bluuebunny/crossref_metadata_2025 huggingface dataset:
Traumatic injuries to enamel formation in rat incisors
Authors: FREDÉN H. , HEYDEN G. , INGERVALL B.
Published: October 2007

abstract – Twenty‐three fullgrown white male rats were fitted with an inclined plane on the mandibular incisors with consequent raising of the bite by 2.5 mm. After an observation period of between 1 and 30 d the animals were killed. In all cases traumatic injuries to the enamel organs were seen. The defects were mainly of four different types. Type 1 occurred in the early maturation zone of the enamel as a local defect with dedifferentiated ameloblasts. Vascular injury was moderate and deformation of the dentin was seen. After 30 d there was still a local defect of the enamel organ. Type 2 occurred apically to the maturation zone and caused a two‐layered ameloblastoma resembling a sandwich. Hemorrhages were common in the surrounding connective tissue, with accompanying appearance of phospholipids in the tissue. After 30 d some restitution of the enamel formation was seen. Type 3 was characterized by fractures of the dentin associated with total ameloblastic injury. Vascular necrosis was seen in the surrounding tissue. After 30 d a new ameloblastoma had developed in some areas. These three types appeared separately or combined. Type 4 occurred as a folding of newly formed apical dentin in areas without differentiated ameloblastoma and was seen in all of the experimental animals.
Effect of soluble plaque factors on inflammatory reactions in the dental pulp
Authors: BERGENHOLTZ GUNNAR , LINDHE JAN
Published: October 2007

abstract – The present investigation was undertaken to determine whether soluble factors from human dental plaque are capable of inducing or mediating pathological alterations in the dental pulp. The experiment was performed in three monkeys and involved 40 teeth in all: 20 test and 20 control teeth. Class V cavities were prepared on the buccal surface close to the marginal gingiva. In the test cavities an extract of human dental plaque was applied once every 5 min during an 8‐h period. The cavities of the contralateral teeth were treated in an identical manner but with Ringer's solution. The animals were sacrificed 10 or 32 h after the initiation of the test. Two hours prior to sacrifice the animals were injected with colloidal carbon and then perfused with 10 % neutral buffered formalin. Histologic examination demonstrates that the pulp tissue response to topical application of a plaque extract was characterized by (1) increased degree of carbon retention — indicative of vascular exudation and (2) enhanced rate of emigration of neutrophils and monocytes.
Haemophili in developing dental plaque
Authors: KILIAN MOGENS , PRACHYABRUED WORALUCK , THEILADE ELSE
Published: October 2007

abstract— Evidence for a possible role played by oral haemophili in the development of dental plaque was sought by studying the occurrence of these bacteria in early dental plaque of smooth surfaces and occlusal fissures in six dental students. The mean number of haemophili per 103 anaerobes in early smooth surface plaque (18 h) and fissure plaque (7 d) was 95 and 22 respectively. Examination of 988 Haemophilus isolates revealed that H. parainjluenzae was the only species in samples of fissure plaque, whereas some samples from smooth surfaces, in addition to the predominating and ubiquitous H. parainfluenzae, yielded growth of the two species H. segnis and H. aphrophilus. It is concluded that haemophili are among the primary colonizers of smooth surfaces of teeth.
A quantitative microradiographic study of oral leukoplakias
Authors: ANNEROTH GÖRAN , FORNANDER BJÖRN , LINDSTRÖM BO
Published: October 2007

abstract— Biopsies from 13 oral leukoplakias and from normal tissue specimens in the contralateral region of each patient were examined histologically and microradiographically. Microradiographs of freeze‐sectioned and freeze‐dried sections were made and quantitative photometric analyses of the distribution of the dry mass concentration in different epithelial cell layers of both normal and pathologic specimens were performed. In each microradiograph, the thickness of the stratum corneum was determined. The results indicated that in oral leukoplakia two main changes occur in the epithelial surface layer, i.e. an increase of the thickness of the surface epithelial cell layer, and a formation of an epithelial surface zone of cell layers with different degrees of keratinization and varying dry mass concentrations.
Initiation and aggravation of denture stomatitis by sucrose rinses
Authors: OLSEN INGAR , BIRKELAND JAN MAGNE
Published: October 2007

abstract— The purpose of this study was to assess whether frequent exposure to sucrose would aggravate or initiate a palatal candidosis in denture wearers. Eight subjects with generalized simple or granular inflammation in the palate (inflammation group) and six with clinically healthy palatal mucosa (control group) carried out 1‐min mouthrinses with 10 ml of a 25% sucrose solution four times daily for 15 d. In the inflammation group an aggravated palatal erythema was seen in two subjects after 7 d, and in another subject after 15 d. Among the controls a generalized simple inflammation had developed in the palate of one subject after 7 d, and in another one after 15 d. An increased number of yeast colonies on palatal and denture agar models and/or hyphae on palatal and denture smears was found in all subjects with clinical signs of aggravated or initiated denture stomatitis.
A pilot study on the effect of toothbrushing on the gingival of a beagle dog
Authors: SANGNES GUDRUN
Published: October 2007

abstract— The maxillary canine and premolar areas of a beagle dog were brushed according to the roll and the scrub toothbrushing techniques. Characteristic, reproducible soft tissue lesions could be associated with the brushing.
Studies on fluoride distribution in infants and small children
Authors: HELLSTRöM INGRID
Published: October 2007

abstract— The fluoride (F) concentrations in hard tissues and blood plasma were determined in biopsy and autopsy specimens from fetuses, infants, and children on varying F intake. In newborn autopsy cases specimens consisting of rib, jawbone with teeth, and blood plasma the F concentrations of bone and dentin were of the same order, those of the enamel lower. Correlations between individual F values in different tissues were all positive, highest for enamel/dentin. Low birth weight entailed only slightly reduced F contents, high water F significantly increased F contents. In the biopsy material (rib and blood plasma) the maximal rib/ash concentration was about 400 parts/106 F. A negative correlation between rib F and plasma F is specially commented on. The possible influence of F on bone development as expressed by blood plasma F and phosphatase activity was investigated in three groups of infants aged 2–6 months, either breast‐fed or fed dry‐milk formulas diluted with drinking waters of different F content. The children of these groups were calculated to ingest F in the ratio of about 1:10:50. The highest F group had higher plasma F values than the two other groups, whereas its alkaline phosphatase was significantly higher than that of the lowest F group only. The influence of disturbances in the skeletal development on F retention was studied in physically handicapped children aged 4–15 years living in a city with about 1 part/106 F in the drinking water. The severely handicapped showed a higher urinary F excretion than the controls.
The occlusal fissure of unerupted third molars as an experimental caries model in man
Authors: FEJERSKOV O. , SILNESS J. , KARRING T. , LÖE H.
Published: October 2007

abstract— The aim of the present Investigation was to establish an experimental model for the study of fissure caries development under conditions as similar as possible to the in vivo situation. Twenty‐one blocks (2×2×3 mm) constituting part of the occlusal fissure were made from unerupted human third molars, and implanted for 60 or 90 d in mandib‐ular molars of students. One milliliter of a 50 70 sucrose solution was applied to the fis‐sures twice a day. After removal, sections were examined microradiographically in polarized light and in the electron microscope As a control, the morphology and enamel structure of fissures from 10 unerupted third molars were studied. After 90 d a subsurface, radiolucent caries‐like lesion was observed in two specimens only. When examined in air in polarized light, however, all sections exhibited caries‐like lesions symmetrically located around the fis‐sures. The 60‐d material showed similar lesions, but not as frequently as the 90‐d speci‐mens. In the control material, half of the specimens demonstrated subsurface lesions as well. The experimental material processed for electron microscopy revealed that the fissure plaque mainly consisted of cocci and small rods. Most often the bacteria were separated from the enamel surface by a pellicle.
Prevalence of gingivitis among children with and without school dental service
Authors: HOLST DORTHE
Published: October 2007

abstract— In order to evaluate the effect of school dental care on the prevalence of gingivitis in children, two groups of children in the 7th grade (approx. age 13—14 years) were compared, only one of the groups having had school dental service. A total of 758 children from eight different provincial towns in Denmark were studied. Gingivitis was recorded by the method of Löe & Silness. The results are given as the average sum of sound, inflamed, and severely inflamed gingival zones and in frequency tables. There were only small differences between those children who had had school dental service and those who had never received it.
Size of nucleus and nucleolus in quantitative electron microscopy on orthokeratinized leukoplakias
Authors: MEYER J. , ALVARES O.A. , WATERHOUSE J. P. , ROED‐PETERSEN B. , PINDBORG J. J.
Published: October 2007

abstract— Eleven leukoplakias of the homogeneous orthokeratotic type and control areas in the same patient were studied by means of standardized electron microscopic preparations of biopsy material and by methods of stereology applied to electron micrographs. In leukoplakias, nuclei and nudeoli were consistently enlarged at three epithelial levels, nucleoli in the basal cells averaging twice the control size. Comparison with specimens of mucosa of the hard palate showed that the enlargement of nuclei and nucleoli in orthokeratinized leukoplakias was in excess of the normal size differential between inherently orthokeratinized and nonkeratinized regions of the human oral mucosa. This suggests an abnormal stimulation of proteinsynthetic activity even in this prognostically “benign” type of leukoplakia.
Urinary fluoride excretion in small children following short‐term fluoride supply with tablets or domestic salt
Authors: HELLSTRÖM I. , ERICSSON Y.
Published: October 2007

abstract – Urinary fluoride (F) excretion has been studied in small children, with some comparisons with adults, following ingestion of F tablets or fluoridated salt (F‐salt) containing 500 mg F/kg NaCl. 24‐h urinary F in 7‐ to 8‐year‐old children in an institution and in 2‐ to 12‐year‐old children in families rapidly increased to average levels of about 0.85 and 0.55 parts/106, respectively, when the children had their meals spiced with F‐salt. Children in families also showed significantly elevated urinary F excretion with two F‐salted meals a day but not with one a day. After taking 0.5 mg F in the form of NaF tablets a group of children without previous F supply attained within 1 d a 24‐h urinary F concentration which was about the same as that in children who had been taking caries‐preventive tablet doses for years. The percentage of a single F dose excreted in the urine within 4 h after the ingestion of F tablets or an F‐salted standard meal was about the same in preschool children and middle‐aged adults. F quantities of the order 1.5–2 mg could be ingested by a child eating a meal comprising strongly F‐salted dishes, and the urine could reach concentrations around 3 parts/106 F during the following 2–4 h. The results obtained support the concept that domestic salt containing about 500 parts/106 F is suitable for clinical testing on a larger scale under Swedish conditions. Calculations of F supplies to children aged 2 months‐7 years with different diets and water and salt F contents are presented as digrams.
Root fractures in permanent anterior teeth with incomplete root formation
Authors: JACOBSEN INGEBORG
Published: October 2007

abstract – A follow‐up study was made of seven teeth with incomplete root formation observed in a group of 66 permanent anterior teeth with root fracture. Three fractures were overlooked on the initial radiographs, two other teeth were suspected of being fractured, and an accurate diagnosis was made in two cases only. All teeth exhibited markedly increased mobility at the initial examination, and slight dislocation of the coronal fragment was found in two teeth. Following reduction (two teeth) and fixation (all teeth), the observation period ranged from 1 1/2 to 19 years. Retained pulp vitality, repair in the fracture area and, most important, approximately normal root development with closure of the apical foramen were observed in all teeth. Even the occurrence of re‐fracture in two seemingly repaired teeth did not jeopardize the long‐term result.
Polarized light microscopy of enamel structure in incisors from newborn infants
Authors: THYLSTRUP A. , FEJERSKOV O. , LARSEN M. JOOST
Published: October 2007

abstract – Enamel structure in human primary incisors was histologically examined in order to compare the observations with those from recent studies on incipient carious and fluorosed enamel. Ground sections from mandibular incisors of five full‐term human infants were examined in polarized light using aqueous media (water, Thoulet's media), alcohols with different refractive indices, and quinoline. Imbibition graphs were made along traverses from the amelodentinal junction (ADJ) to the enamel surface. Quantitative assessments of the birefringence in different media along the traverses indicated a change in the relative volumes of crystallites and surrounding medium with a continuous growth of crystallites toward the ADJ. The influence of organic material is discussed in relation to the differences in calculated form birefringence observed within the specimens. When examined in quinoline, a 30–40‐μm‐thick surface zone appeared distinct positively birefringent, indicating that the outermost enamel reacted as a molecular sieve. Because of the lower content of minerals the interpretation of this zone differed from that of similar “dark zones” observed in carious and fluorosed enamel.
Fluoride reactions with dental enamel following different forms of fluoride supply
Authors: HELLSTRÖM I. , ERICSSON Y.
Published: October 2007

abstract – The reactions with dental enamel of NaF as tablets dissolved in different beverages or supplied with NaCl, simulating domestic salt fluoridation, were studied in tests with enamel surfaces and enamel powder. It was confirmed that powdered enamel can react quite differently from enamel surfaces under certain conditions. Enamel surfaces took up much more fluoride (F) from orange juice than from water or milk, and neither the low pH nor the citrate content of the juice increased the formation of unstable CaF2 in the enamel, as judged from a KOH leaching test. The F uptake by enamel surfaces from 0.25 mM NaF in 175 mM NaCl, corresponding to a dish prepared with salt containing 500 parts/106 F, was about 80% greater than from the same NaF concentration in water. This NaCl concentration did not increase the formation of CaF2 in the enamel, as judged from the KOH test, while 350 mM NaCl caused a moderate increase. The investigations support the administration of NaF tablets with orange juice and the plans for domestic salt fluoridation.
Mandibular kinesthesia in fatigue of human jaw muscles
Authors: CHRISTENSEN L. VESTERGAARD
Published: October 2007

abstract – Fatigue was developed by four human subjects after negative work, and by two subjects after negative/positive work by the jaw muscles. Another four subjects did not develop fatigue subsequent to muscular exercise. In subjects with fatigue, the ability to perceive and/or produce repetitively a predetermined mandibular posture, i.e. mandibular kinesthesia, was impaired by about 285 %. It is suggested that the distorted kinesthesia resulted from either a fatigue‐induced failure of, or a fatigue‐induced persistence of, jaw muscle fibers to contract, which in turn led to distorting flows of afferent impulses from muscle spindles and/or tendon organs.
On the solubility of zinc in the γ‐phase of the silver‐mercury system
Authors: JENSEN S. J. , ANDERSEN P. , OLSEN K. B. , UTOFT L.
Published: October 2007

abstract – By measuring lattice constants of a number of Ag‐Hg‐Zn alloys with γ‐phase structure, it has been shown that apart from a possible two‐phase field there exists a continuous solid solùtion between γ(Ag‐Hg) and γ(Ag‐Zn). A correlation between the Zn‐content in the γ1 phase in set dental silver amalgam and the Zn‐content in the corresponding alloy has been determined.
Evaluation of fissure sealing with a diluted composite sealant and an UV‐light polymerized sealant after 36 months' observation
Authors: ULVESTAD HARALD
Published: October 2007

abstract – The idea of fissure sealing has found wide acceptance in caries prevention. The present investigation was initiated to evaluate the retention of a diluted composite material used as a fissure sealant, compared with the retention of an UV‐light polymerized sealant. After an observation period of 3 years, it seems justified to assume that a diluted composite sealant is a fully acceptable alternative to an UV‐light polymerized sealant, and the former material seemed to have some advantages: a simpler polymerization procedure, an apparently better wear resistance due to ceramic filler particles, and an easier recognition because of a slight discoloration.
Response to an offer of consultation concerning TMJ‐disorder
Authors: HELÖE BERIT
Published: October 2007

abstract – Based on the assumption that there is a correlation between myofascial pain dysfunction (MPD), headache and/or back pain, this study intended to assess the occurrence of MPD among persons reporting pain in their head or back. Another main purpose was to measure the response to an offer of free examination of teeth and jaws and, if needed, also free treatment of TMJ‐disorder. In an electrotechnical company comprising 698 employees, a total of 27 persons attended for examination after the offer had been presented to two groups selected by two different sampling methods. Of the attendants; women, middle‐aged persons, and persons from the upper social strata were overrepresented. These same categories were also the most likely to report headache and/or back pain. Ten individuals out of the 27 attendants claimed to have experienced some TMJ‐disorder., and these individuals tended also to complain about headache and back pain. A major finding was that the response to the offer was clearly affected by social background. The response pattern was much like that known about the seeking of treatment for MPD — and for dental treatment generally.
Benefits and prognoses following 10 years of a fluoride mouthrinsing program
Authors: BIRKELAND J. M. , BROCH L. , JORKJEND L.
Published: October 2007

abstract – This paper is based upon the mean annual amounts of fillings (filled surfaces) and the DMFS among 6/7‐ to 15/16‐year‐old children. Each age group comprised about 450 children. Cross‐sectional recordings were available prior to the start of a caries‐preventive program based on 2‐weekly fluoride rinses. Cross‐sectional and longitudinal DMFS recordings were different during the 10 years of observation. This indicates benefits exceeding the present 70% reduction in need for fillings and 50% improved caries prevalence. The ratio fillings needed for giving the DMFS score among 13‐ to 14‐year‐old children was found to improve from 1.60 to 1.16. Based on the cumulative amounts of fillings and the ratio of fillings DMFS, a DMFS of 15 may be expected in 4 years among children 15–16 years old. This caries prevalence is not markedly different from DMFS recordings among Scandinavian children living in fluoride areas.
The relation between betel chewing and dental caries
Authors: MÖLLER I. J. , PINDBORG J. J. , EFFENDI I.
Published: October 2007

abstract – In the eastern part of Java and on the island of Bali betel chewing is a very common habit confined principally to females. The purpose of the present study was to examine the influence of betel chewing on the prevalence of dental caries. The study, which is based upon 982 villagers, indicates a strong inverse relationship between the prevalence of dental caries and the intensity of betel chewing. The possible mechanisms whereby betel chewing may have a caries‐inhibiting effect are discussed.
Denture stomatitis–yeast occurrence and the pH of saliva and denture plaque
Authors: OLSEN INGAR , BIRKELAND JAN MAGNE
Published: October 2007

abstract – The study comprised 30 denture wearers with generalized simple or granular inflammation in the palate and 30 without (controls). Yeasts, mostly Candida species, were cultivated from the maxillary dentures of all subjects with inflammation and of 23 controls. Hyphae were found in the maxillary denture smears from 28 subjects with inflammation and from 18 controls. Thus it seems unjustified to consider the occurrence of hyphae pathognomonic of denture stomatitis. The pH of whole saliva did not differ in the two groups (inflammation: mean pH 6.5, control: 6.6). There was no clear relation, between the pH of resting saliva and the amount of fungal cultures. Thirty minutes after a mouth rinse with 10 ml of a 25% sucrose solution, the mean saliva pH had dropped equally in both groups. With regard to the denture plaque, samples taken 40 min after the rinse indicated a more pronounced acid production in the plaque associated with inflammation. The pH of “resting” plaque was also lower in the inflammation than in the control group (mean maxillary pH 5.7 and 6.3, respectively, α= 0.002). No association was found between the pH and the occurrence of hyphae in “resting” denture plaque. This supports the view that the pH is of no major importance for filamentation in vivo.
Effect of topically applied neutrophil leukocyte extract on normal gingiva of dogs
Authors: KAHNBERG K.‐E. , HELLDÉN L.
Published: October 2007

abstract – Seven beagle dogs were used to study the gingivitis‐inducing potential of a topically applied neutrophil leukocyte extract and to compare the vascular and cellular reactions with those induced by plaque extract applied in an identical manner. In four dogs neutrophil extract was applied onto the marginal gingiva in one jaw quadrant while Gey's medium was applied to the contralateral gingival units. In the remaining three dogs plaque extract and Gey's medium, respectively, were applied in the same way. After 6.5 h of topical application colloidal carbon (1 ml/kg bodyweight) was injected into a leg vein and after a further 1.5 h biopsies were obtained from the experimental regions. The results show that topical application of an extract from neutrophils induces both an increase in the number of crevicular leukocytes and an enhanced vascular permeability. As in previous studies plaque extract was found to promote the emigration of leukocytes and to alter the permeability of the dentogingival vessels. The vascular and cellular reactions were, however, more pronounced after application of plaque extract than after neutrophil extract.
Variable expressivity of Crouzon's syndrome within a family
Authors: KREIBORG SVEN , JENSEN EIRGIT LETH
Published: October 2007

abstract – Three individuals in two generations affected with Crouzon's syndrome are reported. The proband, a 10‐year‐old boy, had not been diagnosed until the age of 4. His 3‐year‐old sister had not been diagnosed previously and his mother was unaware of having the syndrome and had never received any genetic counseling. The individuals are reported with emphasis on clinical and roentgencephalometric variation. The ultimate goal in teratology is prevention. Currently one of the most important factors related to prevention is genetic counseling in conditions with well‐documented modes of inheritance. The present report describes how the variable expressivity of Crouzon's syndrome within a family had caused diagnostic problems and consequently had delayed genetic counseling.
Scanning and transmission electron microscope study of pellicle morphogenesis
Authors: LIE TRYGGVE
Published: October 2007

abstract – The morphology of pellicle formation was studied using correlated transmission and scanning electron microscopy. Pellicle developed on hydroxyapatite/epoxy resin splints attached to the buccal surfaces of molars and premolars in six young individuals. Splint segments were removed at intervals of 2, 4, 6, 12, 24, and 48 h. Measurements of pellicle thickness revealed that during the first 12 h considerably more material formed on the apatite surfaces than on the epoxy resin areas of the splints. This difference was equalized in 24‐ and 48‐h specimens. Three types of pellicles could be distinguished on the basis of morphologic criteria. A globular pellicle., characterized by a consistent presence of globules of varying size and configuration, seemed to predominate in most subjects. These globules could not be mistaken for bacteria due to their dimensions, contour, and lack of cell walls. A fibrillar pellicle consisted of 3‐ to 7‐nm‐wide fibrils and frequently included some finely globular particles. A granular pellicle displayed a relatively even surface contour and did not exhibit globular or fibrillar structures. In contrast to the two other types, the granular pellicle contained distinct laminations. Apparently, the varying morphology of the early pellicle is a reflection of its complex chemical composition.
A longitudinal radiographic study of the mineralization of 2nd premolars
Authors: RAVN J. J. , NIELSEN H. G.
Published: October 2007

abstract – Odonotogenesis of the 2nd premoiar begins in the majority of cases at the age of 3–31/2 years, although this period can vary more widely than that for other permanent teeth. For this reason, aplasia of this, group of teeth cannot be diagnosed as early and with the same degree of certainty. A group of 104 children aged 3–7 years in whom one or more tooth germs mesial to the 1st permanent molar were not visible in the various age groups was reexamined radiographically in the region where they apparently lacked the development of tooth germs. The second examination tools place 16–24 months after the first, and a comparison was made of the two examinations. The study confirms that the 2nd premoiar can be very late in developing and that the chance of this being so is greater in the maxilla than in the mandible.
Sulfated glycoproteins in the acquired pellicle and in plaque from Macaca fascicularis demonstrated with labeled sulfate
Authors: RÖLLA GUNNAR , EMBERY GRAHAM
Published: October 2007

abstract – A sulfated glycoprotein was demonstrated in 2‐h pellicle material collected from monkeys. Furthermore, a sulfated macromolecule present in plaque extracts was identified as a sulfate glycoprotein by electrophoresis on cellulose acetate strips. The present data indicate that acidic proteins are selectively adsorbed to tooth surfaces in. vivo.
Microflora in the healthy gingival sulcus in man
Authors: SLOTS JÖRGEN
Published: October 2007

abstract – The roll tube culture technique was utilized to examine quantitatively and qualitatively the predominant cultivable microflora inhabiting the clinically healthy gingival sulcus. Seven periodontists aged 32–54 years were included in the study. From a total of 350 isolates, 85 (24.3%) were obligate anaerobes, 53 (15.0%) were Gram‐negative, and 197 (56.3 %) were categorized as rods. Actinomycetes predominated in three samples. Four samples were dominated by Streptococcus species. The flora as revealed in the present study comprised a markedly lower proportion of Gram‐negative organisms than that found at the base of deep periodontal pockets.
Susceptibility of various microorganisms to chlorhexidine
Authors: EMILSON C. G.
Published: October 2007

abstract – The susceptibility to chlorhexidine of bacteria in aerobic, facultatively anaerobic and anaerobic isolates from clinical specimens of wounds, urine, saliva, and dental plaque was studied. Agar diffusion tests using 50 μg chlorhexidine discs and agar dilution tests were performed and the MIC values correlated with inhibition zone diameters, Anaerobic plaque strains were isolated and tested by the agar dilution method in an anaerobic glove box. Regression lines obtained for five agar media demonstrated a good correlation between zone diameters and MIC values. There was a broad range of susceptibility to chlorhexidine among both Gram‐positive and Gram‐negative strains. Low MIC values were noted for staphylococci, S. mutans, S. salivarius and E. coli, while strains of Proteus, Pseudomonas and Klebsiella were less susceptible. S. sanguis showed intermediate susceptibility with both low and high MIC values. Among the anaerobic isolates tested, the strains most susceptible to chlorhexidine were Propionibacterium and Selenomonas, while the least susceptible strains were Gram‐negative cocci resembling Veillonella.
Lipid pattern and fatty acid composition of human palatal oral epithelium
Authors: LEKHOLM ULF , SVENNERHOLM LARS
Published: October 2007

abstract – The lipid pattern and the fatty acid composition of human oral epithelium were studied qualitatively and quantitatively with the aid of thin‐layer chromatography and gas‐liquid chromatography. The material studied consisted of scrapings from the mucosa of the hard palate of nine cadavers and of three volunteers. Two methods for collecting the material were used: A) the epithelium was isolated by the removal of sub epithelial connective tissue from the connective tissue side and B) the epithelium from the epithelial side was carefully scraped off. The lipid pattern of the epithelium was dominated by cholesterol (25 mol %) and phosphoglycerides (total 45 mol %), while triglycerides and free fatty acids constituted 10—15 mol % each. The fatty acid compositions of the lipids were remarkably similar to each other, although the specific characteristics, of each Individual lipid were still noticeable. All lipids showed a large proportion of linoleic acid and a relatively small proportion of other polyunsatured fatty acids. In several respects the lipid pattern and the fatty acid composition of the epithelium were similar to those found in other ectodermal tissues, but they exhibited a number of differences from the corresponding pattern of the rnesenchymal connective tissue.
Evaluation of biologic effects of dental materials using four different cell culture techniques
Authors: HENSTEN‐PETTERSEN ARNE , HELGELAND KRISTEN
Published: October 2007

abstract – The cytotoxicity of fresh and 1‐day‐old silicate cement, composite restorative material and zinc oxide‐eugenol cement (ZOE) was tested using human epithelial cells (NCTC 2544) in four different cell culture systems: (1) 5.1Cr‐release from prelabeled cells after incubation for 4 and 24 h in the presence of the materials, (2) Implanting the materials on an agar overlay and visualizing any cytotoxic effects after 24 h by neutral red vital stain. (3) Cell growth during 5 d in the presence of the materials7hellip; (4) Colony‐forming ability after exposure of the cells for 30 min to medium previously incubated with the materials for 24 h. Freshly prepared and 1‐day‐old ZOE exhibited a prominent cytotoxic effect in all four systems. A less marked effect was found for the composite material in systems 2, 3, and 4, while silicate cement appeared to be the least toxic material in these three systems. Neither silicate cement nor composite showed any cytotoxic effect in system 1 based on51Cr‐release. It is concluded that the effects obtained by the cell culture techniques did not mimic the reactions obtained when the materials are tested under conditions which reflect their clinical use.
Phosphatases and bone growth
Authors: VILMANN H.
Published: October 2007

abstract – By mapping the distribution of resorptive and appositional surfaces in rat skull bones with the help of in vivo staining with alizarin, red S, it has been possible to study the connection between patterns of bone growth and alkaline and acid phosphatase activity on bone surfaces. Alkaline phosphatase activity obviously bears no specific relation to appositional and resorptive surfaces as all surfaces react strongly. Acid phosphatase activity, in contrast, is most marked at sites of resorption.
pH and the effect of fluoride and zinc on protein and collagen biosynthesis in rabbit dental pulp in vitro
Authors: HELGELAND KRISTEN
Published: October 2007

abstract
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The effect of pH in the range 5.6–8.2 on the incorporation of 14C‐proline into the rabbit dental pulp incubated in vitro has been studied. The amount of label in the cold TCA‐pool, total protein, and hydroxyproline (i.e. collagen) of the pulp tissue increased linearly with pH in all three fractions. A similar increase was found in the amount of labeled total protein and collagen recovered from the incubation medium. The results indicated that the uptake of 14C‐proline into the TCA‐soluble pool was the pH‐sensitive step, whereas the incorporation into protein, formation of hydroxyproline, and the release of labeled macromolecules into the medium were not affected to any measurable degree by the ambient pH. In this system, zinc (60 μM) had less effect on the incorporation of 14C‐proline into the different fractions of the pulp tissue at pH 6.6 as compared with pH 7.4, whereas with fluoride (1.3 mM) an increased inhibition of the uptake of 14C‐proline into the TCA‐soluble pool and the incorporation into total protein was found upon lowering the pH to 6.8. The inhibitory effect of zinc and fluoride on the release of labeled total protein and collagen into the incubation medium was not affected when the pH was lowered.
Exact method for clinical measurement of loss of periodontal attachment
Authors: PEDERSEN GERT
Published: October 2007

abstract
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The aim of the present investigation was to develop a clinical method for measuring loss of periodontal attachment, with a measuring unit of less than 1 mm, which did not require surgical intervention, The method was based upon impressions of the pocket area. Sixteen teeth on which the cementoenamel junction was situated below the gingival margin and which were scheduled for extraction for prosthetic reasons were used. Two impressions of the facial gingival pockets of each tooth were taken using steel strips dipped in Coe‐flex® and inserted at the bottom of the pocket. The loss of attachment in relation to the cementoenamel junction was measured in a stereomicroscope with a measuring unit of 0.04 mm. After extraction, the teeth were stained for connective tissue attachment and the loss of attachment was measured. Duplicate measurements and pre‐and post‐extraction measurements of the same situation were compared. The results show that the accuracy and reproducibility of the method is high.
Microorganisms in recurrent aphthous ulcerations
Authors: DONATSKY O. , JUSTESEN T. , LIND K. , VESTERGAARD B. FABER
Published: October 2007

abstract
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Qualitative and quantitative examinations of the cultivable bacterial flora in biopsies from recurrent aphthous ulcerations (RAU), experimental oral ulcerations (EOU), and normal oral mucosa (NOM) were carried out under aerobic and continuous anaerobic conditions. An attempt was made to culture yeasts, mycoplasma, and virus from the biopsies of RAU, which were also tested for the presence of herpes virus antigen by the fluorescent antibody method. The predominant bacteria recovered in RAU were α‐hemolytic streptococci, coagulase‐negative staphylococci, and Neisseria. In EOU the main recoveries were α‐hemolytic streptococci, Corynebacterium, Veillonella, Neisseria, and Haemophilus. In NOM α‐hemolytic streptococci dominated the cultures. Yeasts were only cultured from one patient with RAU. No mycoplasmas or viruses were isolated, nor was herpes virus antigen demonstrated in any of the RAU specimens. The role of the microorganisms in the pathogenesis of RAU is discussed.
Toxicity of some dental cements in a cell culture system
Authors: LEIRSKAR JAKOB , HELGELAND KRISTEN
Published: October 2007

abstract
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A cell culture method has been used to study the effect of zinc phosphate cement (De Trey's Zink Zement Improved®), zinc silicophosphate cement (Fluoro‐Thin®) and polycarboxylate cement (Durelon®) on animal cells. Disks (30 × 1 mm) of the materials were placed in the center of plastic Petri dishes and subsequently incubated with human epithelial cells. Cell multiplication, medium pH and the release of cement constituents were measured. All three cements exhibited a cytotoxic effect, which was most pronounced in the cultures with zinc silicophosphate cement and polycarboxylate cement. The results also indicated that cell growth on the surface of the disks is a more sensitive indicator of cytotoxicity than cell growth around the disks. pH of the medium was only slightly affected in cultures with polycarboxylate cement, whereas a decrease was found in cultures with zinc phosphate cement and especially with zinc silicophosphate cement. A rapid release of phosphate was found in cultures with zinc silicophosphate cement. Zinc was released into the medium from disks of zinc phosphate cement, zinc silicophosphate cement and polycarboxylate cement – exceeding the toxicity level for the present cell line after 24 h. In cultures with zinc silicophosphate cement and polycarboxylate cement the release of fluoride reached toxic levels within the same time interval.
Galvanic series of some dental alloys
Authors: ARVIDSON KRISTINA , JOHANSSON E. GUNNAR
Published: October 2007

abstract
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Galvanic series for different metals in different electrolytes have been published, but never for dental alloys in artificial saline solution. The material classes studied are amalgam, gold alloy, nickel alloy, chromium cobalt casting alloy and temporary crown form. The electrogalvanic potentials were measured and determined in reference to a hydrogen electrode (H2/H+) arbitrarily defined as zero. A galvanic series of the tested materials was arranged in order of their potentials.
Measurements of currents between dissimilar alloys in the oral cavity
Authors: GJERDET NILS ROAR , BRUNE DAG
Published: October 2007

abstract
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A method is described for the measurement of currents generated between dissimilar alloys in the oral cavity. Tests were performed using amalgam fillings versus specimens consisting of a gold alloy, a chromium‐cobalt alloy and a stainless steel alloy. Currents of 0.1–0.3 μA/cm2 of specimen area were measured.
Calcium fluoride formation on enamel and its influence on uptake of fluoride in the apatitic lattice
Authors: LARSEN M. JOOST , JENSEN S. J. , THORSEN ANETTE
Published: October 2007

abstract – Human dental enamel was exposed to a pH 4 buffer containing 150 parts /106 fluoride. It was found that due to the arising degrees of saturation with respect to calcium fluoride and appetites, surface enamel dissolved coincident with a formation of calcium fluoride. The calcium fluoride redissolved while it kept the liquid saturated with respect to tiiis salt. During this second period, fluorapatite was formed while hydroxyapatite dissolved. Finally, all calcium Ouoride was dissolved and the unreacted fluoride was taken up in the apatidc lattice. The results are discussed with reference to the conditions of the oral cavity and enamel solubility experiments.
Quantitative observation on teeth during calcium deprivation in rats
Authors: RASMUSSEN P.
Published: October 2007

abstract – Adult female rats were subjected to severe calcium deprivation by Feeding them a calcium‐deficient diet containing oxalate (Group A). Furthermore, pregnant and lactating animals were subjected to the same diet (Group B). The mandibular teeth were collected for ash determination and for linear measurements. The ash content of the growing incisors was only slightly reduced in Group A, while the reduction in Group B was 27%. Linear measurements demonstrated that the outer dimensions of the incisors were not affected by the calcium‐depriving regimen in either group, while the inner dimensions (pulp cavity) were considerably increased in Group B due to reduced thickness of the dentin mantle. The daily dentin apposition in Group A did not deviate much from the control values, while in Group B it was severely reduced. The thickness of incisor enamel was unaffected by the calcium‐depriving regimen. The ash content of the molars was normal in Group A, but slightly reduced in Group B.
Retention and effectiveness of a chemically polymerized pit and fissure sealant after 2 years
Authors: THYLSTRUP A. , POULSEN S.
Published: October 2007

abstract— Following a single application of a chemically polymerized fissure sealant (Concise Enamel Bond System®) 60% of the sealants were present after 2 years of examination. The effectiveness of the treatment was highly significant and the caries reduction, irrespective of the sealant status, was found to be about 5096. The caries reduction was 98% in sealed pairs where the material was fully retained.
Fine structure of the human secretory ameloblast
Authors: MATTHIESSEN M. E. , RÖMERT P.
Published: October 2007

abstract— The fine structure of secretory ameloblasts in primary tooth germs from a human fetus was investigated. Various aldehyde fixatives produced varying qualities of preservation. The morphology of the best preserved ameloblasts differed from that earlier described, mainly in the following respects: the rough endoplasmic cisternae were lamellated and regularly arranged, the mitochondria were of regular shape and size, and the ground substance was dense and homogeneous. The extensive Golgi complexes, the mitochondria and the rough endoplasmic cisternae in the apical (distal) part of the ameloblast were longitudinally arranged.
Effect of some polyvalent cations on plaque formation in vivo
Authors: SKJÖRLAND K. , GJERMO P. , RÖLLA G.
Published: October 2007

abstract— The purpose of the present study was to investigate the effect of polyvalent cations on plaque formation in a test panel of students. Heavy plaque formers were selected and plaque formation was enhanced by frequent sucrose rinses. Mouthrinses were performed twice daily with 20 mmol/1 SnF2, SnCl2, AlCl3, ZnCl2 and MgCl2, and 40 mmol/1 NaF and NaCl. It was found that SnF2 and SnCl2 exhibited a marked plaque‐inhibiting capacity compared with NaF or NaCl. The aluminum, zinc and magnesium salts also reduced plaque formation, although not to the same degree. Polyvalent cations may‐prevent plaque formation by interaction with negatively charged plaque components essential in the adsorption mechanism, or by inhibiting some enzyme activity essential in plaque formation.
Effect of inorganic ions and surface active organic compounds on the adherence of oral streptococci
Authors: OLSSON JAN , ODHAM GÖRAN
Published: October 2007

abstract— A reduction in the adherence of oral streptococci was observed after topical application of aluminum ions to standardized dentin test pieces whereas pyrophosphate and tripolyphosphate seemed to inhibit the adherence after incorporation in the incubation solution. A pronounced effect was recorded after topical application of surfactants with the positively charged primary amino group as end group. Hydrofluorides of several such aliphatic amines effectively reduced the number of colony‐forming units washed off from the test pieces. Also the free base of hexadecylamine showed a similar effect. Inhibition of adherence was also obtained with long chain esters of lysine, with an optimum at 16 carbon atoms in the alcohol group. These compounds have the advantage of being built up from molecules known to the body.
Effect of dextranase on plaque formation and caries development in the rat
Authors: POULSEN S. , LARSON R. H. , SENNING R. S.
Published: October 2007

abstract— Plaque formation and caries development were studied in 0‐M rats fed Diet 2000 and infected with S. mutans 6715 and fecal flora from older caries‐active rats. Merck dextranase, Beckman dextranase or Beckman glucanase 447 were administered singly or in combination to groups of 12 rats either as an addition to the diet or as a “mouthwash” twice daily, 5 d per week. All enzymes studied were associated with significant inhibition of both plaque formation and caries development, especially on the buccal and lingual surfaces.
Relation of amylase to starch and Lycasin® metabolism in human dental plaque in vitro
Authors: BIRKHED DOWEN , SKUDE GUNNAR
Published: October 2007

abstract— Acid production activity (APA) in plaque suspensions from glucose, boiled soluble starch and hydrogenated starch hydrolysate (Lycasin®) was studied in 11 subjects. Amylase (alpha‐1,4‐glucan 4‐glucanohydrolase, EC 3.2.1.1) activity was measured in plaque and whole saliva samples from the same persons. Lycasin was found to be hydrolyzed by salivary amylase under the formation of di‐ and oligosaccharides, however, with a lower rate than starch. A high correlation was found between APA from glucose and from soluble starch and between APA from soluble starch and plaque amylase activity. No correlation was found between amylase activity in saliva and APA from soluble starch or between amylase activity in saliva or plaque and APA from Lycasin. APA from Lycasin was about 62% and from soluble starch about 76% of the APA from glucose. 0–25% of the total number of cultivable microorganisms from the plaque produced extracellular starch‐degrading enzymes. No correlation was found between number of starch‐degrading microorganisms and APA from soluble starch or between these numbers and the plaque amylase activity. By electrophoreses only amylase fractions of human origin were found in whole saliva, plaque supernatants and plaque suspensions, indicating that the microbial amylase activity in the plaque is low compared with that of salivary origin.
Histochemical and radiologic studies of the human fetal mandibular condyle
Authors: KJAER INGER
Published: October 2007

abstract— Histochemical investigations on the mandibular condyle were performed on 72 human embryos and fetuses of crown‐rump lengths (CRL) ranging from 26 to 186 mm, representing skeletal maturity indices expressed in CNO values (CNO=composite number of ossified bones in the hand and foot) ranging from 0–0 to 19–12. The development of the mandibular condyle is described according to morphology and to histochemical reactions for glyicosaminoglucuronoglycans, collagen, glycogen, alkaline and acid phosphatase, and nonspecific AS esterase. The development is described for (1) the bony component of the mandibular condyle, (2) the condylar cartilage, and (3) the fibrous cover of the mandibular condyle. For each tissue component, maturation steps are set up and included in the total evaluation of the condylar maturity stages. The developmental sequence set up on the basis of the morphologic and histochemical findings was followed by all condyles investigated. From this it may be presumed that the developmental sequence in human mandibular condylar components is constant during the former half of the prenatal period. The material available did not justify a description of skeletal development in the mandibular condyle as a function of fetal size, CRL, or skeletal maturity in the hand and foot.
Effect of chlorhexidine‐coated dressing on plaque formation after gingivectomy
Authors: BAY LENA M. , LANGEBAEK JØRGEN
Published: October 2007

abstract— The aim of this clinical study was to evaluate the effect on plaque formation after gingivectomy when the periodontal dressing Coe‐Pak® was coated with chlorhexidine hydrochloride powder. The study indicates that no additional plaque‐inhibiting effect can be obtained by this method.