bluuebunny/crossref_metadata_2025 huggingface dataset:
In vitro studies of fluoride uptake in human enamel
Authors: LARSEN M. JOOST
Published: October 2007

abstract— In a closed agitated system, which included an enamel surface and a continuously magnetically stirred buffer at pH 4.0, 5.0, 6.0 and 7.0, the reaction (Ca5(PO4)3OH)S+F−→(Ca5(PC4)3F)S+OH− was investigated kinetically by measuring the fluoride ion activity. The buffers initially contained 1 part/106 fluoride. Six experiments were carried out at each pH. It was found that the reaction followed first order kinetics. The rate of the reaction was very slow at pH 7.0, but increased considerably when pH was lowered, and at pH 4.0 it was 100 times that at pH 7.0. In supplemental experiments it was found that reducing the area of the enamel surface reduced the rate of the reaction. The results are discussed with reference to equilibrium conditions in water‐apatite systems, assuming that equilibrium cannot be attained when hydroxyapatite is dissolving and fluorapatite is being formed. The findings are considered to explain the increased amount of fluoride present in the residual apatite in developing carious lesions, and may initiate new principles in the local treatment of teeth with fluorides.
Radiography of the temporomandibular joint after oblique sliding osteotomy of the mandibular rami
Authors: HOLLENDER LARS , RIDELL ARNE
Published: October 2007

abstract— A radiographic follow‐up of the temporomandibular joint in 25 patients subjected to oblique sliding osteotomy of the mandibular rami showed a remodeling of the condylar head. Distinct double contours in the posterior part of the condylar heads were found in 30 out of 36 joints with a forward‐inferior displacement of the condylar head.
Structure of experimental in vitro and in vivo lesions around composite (Addent XV®) fillings
Authors: HALS EINAR , KVINNSLAND INGER
Published: October 2007

abstract— In the in vitro experiments of the present study Class V Addent XV® fillings were inserted on buccal surfaces of 32 permanent human teeth. Lesions were produced by placing acidified gelatin around the fillings. In the corresponding in vivo experiments, caries was produced around similar fillings in 17 permanent teeth. In both series, sections of the teeth with the fillings in situ were studied by polarized light microscopy and microradiography. All teeth showed “outer lesions”, but the tendency to development of “cavity wall lesions” was negligible. A comparison with lesions produced previously in corresponding experiments with silver amalgam and silicate fillings has been done.
Effect of chlorhexidine mouthrinse and periodontal treatment upon bacteremia produced by oral hygiene procedures
Authors: MADSEN KAI LYNGGAARD
Published: October 2007

ABSTRACT – Toothbrushing for 21/2 min and the use of toothpicks for 21/2 min produced bacteremia with streptococci in seven out of 13 patirnts with destructive periodontitis and in dontitis group and the “gingivitis” group was not significant, but there scemed to be more frequent bacteremia in the periodontal group. No correlation could be established between plaque‐index, gingival‐index and positive bacteremia. Barteremia seemed to be due primarily to pockets and interdental ulcerations. The use of chlorhexidine as a mouthriuse for 7 d did not reduce the bacteremia caused by the oral hygiene procedures in either of the two groups. After periodontal treatment no bacteremia was detected in the periodontitis group, whereas no reduction was obtained in the gingivitis group.
Pluricolor fluorescent labeling of mineralizing tissue
Authors: SOLHEIM TORE
Published: October 2007

ABSTRACT – The properties of different tetracyclines, alizarin red S, calcein, Procion H‐8B® and hematoporphyrin as fluorescent bone and dentin markers have been tested on growing Wistar rats after intraperitoneal injections. Tetracycline, alizarin red S, calcein and Procion H‐8B were individually identifiable by means of appropriate filter combinations of the microscope. This approach may be useful in prolonged studies of bone growth and reactions. If a fifth marker is needed, mixed injection of tetracycline and Procion H‐8B is recommended. In doses necessary for fluorescence examination, the above recommended substances may be regarded as practically nontoxic. In the dentin, tetracycline and calcein seem to be the best fluorescent markers. Hematoporphyrin is not recommended because of poor labeling properties and general toxicity with weight reduction of the animals.
Mineral content of developing rat incisor enamel
Authors: HALSE A. , SELVIG K. A.
Published: October 2007

ABSTRACT – The contents of Ca and P in developing enamel of the continuously growing rat incisor were examined by the electron microprobe. A longitudinally sectioned, epoxy res‐in‐embedded maxillary incisor from a 5‐month‐old rat was analyzed by linear scans across the enamel at intervals from the growing end. Near the growing end, concentrations of approximately 2 % Ca and 1 % P were found close to the ameloblast‐enamel junction, increasing to 18 % Ca and 9 % P near the dentino‐enamel junction. With increasing distance from the growing end, a successive increase of the mineral content was observed, together with a leveling out of the concentration gradients from the enamel surface to the amelo‐dentinal junction seen at earlier stages of mineralization. Mature enamel contained about 35 % Ca and 17 % P. The results were discussed in the light of previous electron microscopic observations of the same specimen material. It was concluded that in analysis of mineralized tissues in an early stage of development, the mineral content as found by the electron microprobe technique can be considered a valid approximation of the true situation. This technique may also be applied to the study of hard tissues in varying stages of demineralization.
Incorporation of iron in rat incisor enamel
Authors: HALSE A. , SELVIG K. A.
Published: October 2007

ABSTRACT – The electron microprobe technique was used to study the accumulation of iron in rat incisor ameloblasts as well as the subsequent release of iron from the cells and deposition into the outer layer of the enamel. Starting about 3 mm from the developing end, a gradual accumulation of iron occurred in the ameloblasts. At a stage where the iron content of the cells had reached a maximal level, and the calcium content of the adjacent hard tissue had reached the level of mature enamel, the initial incorporation of iron in the enamel was seen. In the iron incorporation zone the iron content of the enamel increased from less than 0.1 % to about 9 % and the iron content of the ameloblasts was gradually reduced. Concomitant with the increase of iron in the enamel, a decrease of the calcium content was observed in the same region, indicating a withdrawal of calcium from the enamel. Since the incorporation of iron occurs at a stage where the enamel is highly mineralized, the processes involved can hardly be explained as an interaction with the organic matrix. The key to the understanding of these processes should therefore be sought in the adjacent cell layer.
Elimination of hyalinized periodontal tissues associated with orthodontic tooth movement
Authors: RYGH PER
Published: October 2007

ABSTRACT – The elimination of orthodontically produced hyalinized tissue in the marginal region of the periodontal ligament has been studied with the electron microscope. From a material of 67 rats in which the first molar had been moved buccally with a fixed appliance for a period of 30 min to 28 d, 20 specimens representing experimental periods of 48 h to 14 d revealed that the hyalinized structures disappeared concomitantly with an invasion of cells and blood vessels from the neighboring periodontal ligament. The removal of collagen, cell remnants and degraded vascular elements apparently was mediated by different forms of cellular activity. Breakdown of collagen fibrils was observed around cell processes as well as in inclusions within the cytoplasm of the invading pioneer cells. Penetration of new blood vessels seemed to be an important factor in the elimination of hyalinized tissue. Remnants of cells and erythrocytes were removed by phagocytic activity, while more extensive amorphous masses of vascular components were eliminated by foreign body giant cell activity. Identification of the invading cells has been discussed in relation to current concepts of connective tissue cell differentiation.
On the mechanism of cytotoxicity of silver and copper amalgams in a cell culture system
Authors: LEIRSKAR JAKOB
Published: October 2007

ABSTRACT – Silver and copper amalgams show a pronounced cytotoxic effect on monolayer cultures of human epithelial cells (NCTG 2544). Analyses of the medium from silver amalgam cultures showed that, zinc was released in substantial amounts (14 μg/ml after incubation for 24 h). Small amounts of mercury and possibly also some silver were released, whereas release of copper and tin could not be. detected. Toxicity tests showed that 10 μg Zn2+/ml reduced the number of cells by 96% after incubation for 24 h. In the copper amalgam cultures about. 100 μg copper and 5 μg, cadmium per ml medium were found after 24 h. Only small amounts of mercury were released, Toxicity tests showed an increasing effect of Cu2+ and Cd2+ with tune. With 50 μg Cu2+/ml the number of cells was reduced by 73% after incubation for 24 h, and after 3 d a similar effect was found with 25 μg/ml. With 10 μg Cd2+/ml no cells were left after 24 h, whereas after 3 d 1μg/ml reduced cell growth by more than 80 %.
Presence in dental plaque of a polysaccharide antigen of the anaerobic oral filamentousorganism Eubacterium saburreum
Authors: HOFSTAD TOR
Published: October 2007

ABSTRACT – Plaque samples were examined by double diffusion in agar for the presence of PS L44, a surface antigen of Eubacterium saburreum. The antigen was detected in eight ofnine samples
Antimony, arsenic, bromine and mercury in enamel from human teeth
Authors: RASMUSSEN E. G.
Published: October 2007

ABSTRACT – The concentrations of antimony, arsenic, bromine, and mercury have been determined in enamel from ancient and contemporary human teeth. Fifty‐two enamel samples were analyzed: 10 from 2300–1500 B.C., 8 from 400 B.C. ‐ 200 A. D., 3 from 800–1100 A. D., 14 from 1100–1400 A. D., 5 from the 1850′s, and 12 from the present time. All teeth were taken from dated skulls or young patients with no fillings. The samples weighed between 30 mg and 60 mg. The concentrations of the four elements were determined after neutron activation and radiochemical separation by means of a Nal(TI) scintillation well detector and a T. M. C. 400‐channel analyzer. The ranges of concentrations were antimony: < 0.001–1.59 μg per g enamel; arsenic: < 0.001–0.406 μg per g; bromine: 0.87–7.3 μg per g; mercury: <C 0.001–1.88 μg per g enamel. It was not possible to group the samples according to differences in concentrations of each of the four elements.
Scanning electron microscopic study of tooth surfaces in pathologic pockets
Authors: SAGLIE REINALDO , JOHANSEN JAN R. , FLÖTRA LEIV
Published: October 2007

ABSTRACT – The surface morphology of the pathologic pocket area of human teeth has been studied with the scanning electron microscope. The topography and morphology of adherent bacterial plaque, epithelial attachment remnants, the completely and partially lyzed connective tissue zone, the most coronal intact connective tissue fibers and the exposed cementum surface are described.
Differential thermal analysis of oral and palmar epithelium
Authors: KAABER SVEND
Published: October 2007

ABSTRACT – Differential thermal analysis has been used to study the number and thermal range of the water‐binding sites in epithelial samples from monkey oral mucosa and palmar epidermis in their hydrated, dehydrated and reliydrated states. Hydration occurred in phosphate buffered saline. Dehydration was performed over saturated salt solutions, and rehy‐dration over water. Hydrated and slightly dehydrated palatal and buccal epithelium demonstrated one free‐water fraction and two bound‐water fractions with endothermal transitions at 103°, 140–160° and 185°C respectively. In rehydrated oral epithelium only one endothermal transition at 135°C was observed. Hydrated and slightly dehydrated palmar epithelium exhibited a similar free‐water fraction at 103°, and three bound‐water fractions at 114°, 135° and 185°C. Rehydrated palmar samples exhibited transitions at 135° and occasionally at 114°C. Dehydrated oral and palmar samples lost their thermal activity gradually. The origin of the bound‐water fractions released at 114° and 135–160°C are discussed.
Observations on the microstructure of the composite filling materials Concise® and Addent XV®
Authors: GJERDET NILS‐ROAR , HALS EINAR
Published: October 2007

ABSTRACT – The purpose of this study was to undertake a microscopic analysis of the structure of Concise® and Addent XV® with reference to matrix and fillers. The material consisted of 60 30–100 μ thick ground sections of teeth in which Class 5 Addent XV or Concise fillings had been inserted. The sections were studied by polarized and UV light (fluorescence) microscopy and contact microradiography. The structure of Concise differed greatly from that of Addent XV. Whereas the fillers of Concise displayed a strong birefringence, those of Addent XV were weakly birefringent. On the other hand, differentiation between fillers and matrix was difficult with Concise but easy with Addent XV. In Addent XV there was an indication of compression zones of the matrix bordering the fillers and accidental airspaces. A 20–300 μ wide rim of matrix at the borders of the fillings showed stronger birefringence than the bulk of the matrix. This birefringence remained unchanged during imbibition of the sections in the air (n = 1.0) and watery media (n= 1.33–1.62) series, but was altered by imbibition in alcohol. New type Addent XV available since January 1973 appeared structurally equal to Concise.
Papain‐induced changes in the cranial base of rats
Authors: SGHRAMM J. E. , MELSEN B. , LA COUR S.
Published: October 2007

ABSTRACT – Alterations of the cranial base induced by parenterally administered papain were studied on rats by means of a new microradiographie technique. The material consisted of 28 males and 36 females, randomly divided into one papain injected group and one saline injected. The experiment started when the rats weighed 90 ± 5 g, and daily injections were given for 12 d. Differences between experimental and sham‐operated animals were most pronounced in the males. Apart from the length of the presphenoid bone, all measurements in males were reduced, whereas in females only the total length of the skull, nasal length and length of the basisphenoid bone were significantly smaller in the papain than in the saline injected animals. The influence of papain on angular measurements was also greater in males than in females, akhough the type of alterations found was the same. It is suggested that the alterations are caused by changes in the degree of differentiation in synchondral growth.
Caries reduction 1.5 years after application of a fissure sealant as related to dietary habits
Authors: MEURMAN J. H. , LUOMA H. , HEIKKIL H. , RAUTIO P.
Published: October 2007

abstract— Findings 1.5 years after the application of the sealant revealed that among the 200 sealed permanent first molars, 2.5% of the sealants were lost or partly missing, while 95% of the sealants remained in good condition. During the test period, 7 of the 200 sealed permanent fissures had become carious, while 64 of the respective control fissures had decayed. The percentage effectiveness of the prevention by the present method was 85%. Four out of five molars that had lost the sealants became carious, but of the 190 molars having sealants in good condition, only three were diagnosed as carious. All teeth reported as contaminated with saliva at the sealing session had lost the material. No correlation could be found between the type of food eaten or oral hygiene habits of the subjects and the retention of the sealants.
Degrees of saturation with respect to apatites in fruit juices and acidic drinks
Authors: LARSEN M. JOOST
Published: October 2007

abstract— Some fruit juices and carbonated acidic drinks, recognized as agents causing dental erosions, were analyzed for calcium, phosphate, fluoride and pH. Ionic activity/concentration products for hydroxyapatite and fluorapatite were calculated. It was found that all liquids analyzed were unsaturated with respect to both apatites, which explains their erosive effect.
One‐hour compressive strength of dental amalgam
Authors: ESPEVIK S.
Published: October 2007

abstract— The one‐hour compressive strength of 22 commercially available dental amalgams has been measured. Large differences between different alloys were observed. It was recognized that an intermediate one‐hour compressive strength is probably the most desirable in view of the other properties which are involved.
The location of zinc in dental silver amalgam
Authors: JENSEN S. J. , ANDERSEN P. , OLESEN K. B. , UTOFT L.
Published: October 2007

abstract— The phases in amalgams prepared from alloys of varying zinc content and with varying alloy‐to‐mercury ratios have been determined by means of X‐ray diffraction. By measuring lattice constants of the phases in these amalgams it has been established that the major part of the zinc, is dissolved in the γ1 phase.
A 3‐year clinical follow‐up study of pulpotomized primary molars treated with the formocresol technique
Authors: RöLLING INGE , THYLSTRUP ANDERS
Published: October 2007

abstract— The purpose of the present investigation was to evaluate the prognosis of primary molars treated with pulpotomy employing formocresol. The material consisted of 98 primary molars. The study included clinical and radiographic observations 3, 12, 24 and 36 months after treatment. The survival rate at the 3‐month follow‐up was 91%, whereas the rate was 83%, 78% and 70%– 12, 24 and 36 months respectively after the treatment. The results were computed according to the life table method.
Blood group antigens A and B in ameloblastomas, odontogenic keratocysts and non‐keratinizing cysts
Authors: VEDTOFTE P. , DABELSTEEN E.
Published: October 2007

abstract— The expression of blood group antigens A and B has been studied in 8 ameloblastomas, 16 odontogenic keratocysts from patients with basal cell nevus syndrome, 11 odontogenic keratocysts from patients without the syndrome, and 12 non‐keratinizing odontogenic cysts, using a double layer immunofluorescence staining technique. The amount of antigen in the lesions was compared with the content of antigen in normal buccal mucosa from each patient. All ameloblastomas reacted negatively, three cysts from the patients with the basal cell nevus syndrome reacted negatively, and the odontogenic keratocysts from patients without the syndrome as well as the non‐keratinizing odontogenic cysts all gave a positive reaction.
Microscopic features of the lateral periodontal cyst
Authors: SHEAR M. , PINDBORG J. J.
Published: October 2007

abstract— The lateral periodontal cyst is of developmental odontogenic origin and must be differentiated from the gingival cyst of adults, a primordial cyst in a lateral periodontal position, and a cyst of inflammatory origin. This paper is based on a histologic study of five cases. Four were in the mandibular premolar region and one in the lateral incisor‐canine region of the maxilla. The cysts are lined by a thin non‐keratinized epithelium which resembles the reduced enamel epithelium. Many of them are characterized by the presence of localized plaque‐like thickenings of their epithelial linings, consisting of fusiform or large swollen, edematous cells. These epithelial thickenings appear to result from a localized proliferation of basal cells. The lateral periodontal cyst may arise initially as a dentigerous cyst which develops by expansion of the follicle along the lateral surface of the crown and comes to lie on the lateral aspect of the root if tooth eruption is normal. Alternatively, it may arise from the cell rests of Malassez.
Enamel damages caused by contracting restorative resins
Authors: JÖRGENSEN KNUD DREYER , ASMUSSEN ERIK , SHIMOKOBE HIROKATA
Published: October 2007

abstract— Several observations have shown that contraction stresses in restorative resins bonded to the enamel of cavity walls readily broke the enamel surrounding the cavities. The forces studied were caused by polymerization contraction, thermal contraction or elastic hysteresis. The bonding was obtained mainly by etching the cavity walls by phosphoric acid.
Dose and age dependent variations in effect of tetracycline on enamel formation in rat
Authors: WESTERGAARD J. , NYLEN M. U.
Published: October 2007

abstract— Incidence of rats with gross enamel lesions in response to tetracycline hydrochloride (TC) was studied in relationship to age, tooth type, and concentration of antibiotic in the injection fluid. Incidence was defined as percentage of animals with defects in at least one incisor or one molar. Serum levels were measured at various intervals in 4‐ and 75‐day‐old rats, which received a single i.p. injection with 130 mg/kg bw in concentrations of either 13 or 25 mg/ml saline. The study confirmed that the effect of TC on enamel varied with age of the animal and that the molar responded more readily than the incisor. Furthermore, the incidence was higher the higher the concentration of antibiotic. This effect appeared tied to a direct relationship between concentration and serum level. Serum levels declined more slowly in the younger than in the older rats, resulting in significantly higher levels 6, 24 and 48 h after dosing, which correlated with a more extensive labeling of the dentin in the young rats. The possible roles of serum levels, capillary supply and cell susceptibility are discussed in relation to differences in response with animal age, between tooth types, tooth surfaces and with age of the secretory cells.
Clinical kinesthetic experiments on the lateral pterygoid muscle and temporomandibular joint in man
Authors: CHRISTENSEN L. VESTERGAARD , TROEST T.
Published: October 2007

abstract— The possible kinesthetic function of proprioceptors in the lateral pterygoid muscle was clinically assessed after anesthesia of muscle and temporomandibular joint receptors, respectively. A mandibular posture was actively and repetitively produced with an average accuracy of 2.5 mm, while the accuracy decreased by about two‐fold after narcotization. It is suggested that muscle spindles in the lateral pterygoid muscle as well as mechanoreceptors in the temporomandibular joint capsule are active in the perception and/or control of mandibular postures.
Creep of dental amalgam
Authors: ESPEVIK S. , SöRENSEN S. E.
Published: October 2007

abstract— The steady‐state creep rates of dental amalgams were measured and the creep rates were correlated with the microstructure of the amalgams. The influence of manipulation variables on creep rate and microstructure was evaluated. The samples were either mechanically or hand triturated, hand condensed, and stored at 20°C for 7 d. The specimens were subjected to a constant tensile load for 24 h, and the elongation was measured with a displacement transducer. The smallest creep rate was found on a spherical amalgam, and the highest on an amalgam made from a preamalgamated fine grain alloy. A correlation between microstructure and creep rate could be demonstrated. The amount of γ2 phase did not seem to influence the creep rate. Amalgams that had large closely packed γ particles surrounded by a small volume fraction of γ1 phase exhibited a low creep rate. Amalgams that had small broken up γ particles surrounded by a large volume fraction of γ1 exhibited a high creep rate. Abusive manipulation of lathe‐cut amalgam alloys resulted in high creep rates, small broken up γ particles and a high volume fraction of γ1.
Morphology of growing bone surfaces
Authors: RASMUSSEN P. JERSILD , SARP O. PLOUG , VILMANN H.
Published: October 2007

abstract— The relation between bone surface patterns and the rate of bone formation and destruction was studied by observing surface sections and ground sections. The material used consisted of the dried skulls of three pigs. Observations on surface sections revealed two principal types of bone surface patterns, i.e. a type characterized by smoothness and regularity and a type characterized by roughness and irregularity. Observations on corresponding ground sections revealed that these patterns represent appositional surfaces and resorptive surfaces, respectively. Within each type of surface pattern, variations occurred. As judged from the corresponding ground section, these variations might express variations in growth rates.
A morphologic description of a dry skull with mandibulofacial dysostosis
Authors: DAHL ERIK , KREIBORG SVEN , BJÖRK ARNE
Published: October 2007

abstract— The morphology of an East Indian, dry skull exhibiting the characteristics of mandibulofacial dysostosis (MFD) is described. The skull was small, but the shape of the calvarium was essentially normal. Extensive anomalies were registered in the sphenoid bone, the temporal bone, the zygomatic bone, the maxilla, and the mandible. A lateral cephalo‐metric radiograph of the skull was compared with a mean value diagram of adult Danish males in order to illustrate the morphologic aberrations of the MFD skull. The etiology and pathogenesis of the syndrome are discussed.
Comparison of five growth media and two anaerobic techniques for isolating bacteria from dental plaque
Authors: SLOTS JÖRGEN
Published: October 2007

abstract— Five agar media in combination with the Hungate roll tube technique and conventional anaerobic jar technique (Baird & Tatlock(r) jars) were evaluated to determine the most suitable medium for non‐selective isolation of the viable microorganisms in dental plaque. The highest colony count was obtained by using “Modified Medium 10” with the roll tube technique. About twice as many plaque colonies were recovered by roll tube technique as by the conventional anaerobic technique. With the MM 10 roll tube technique, 7 d of incubation revealed only 93% of the colonies that could be detected after 14 d of incubation.
pH changes in dental plaque caused by sweetened, iron‐containing liquid medicine
Authors: LöKKEN P. , BIRKELAND J. M. , SANNES E.
Published: October 2007

abstract— Five commercially available liquid iron medicines and a 5% aqueous sucrose solution were tested in a randomized cross‐over study with six subjects at intervals of 3–4 d. The pH in plaque was measured in minute samples taken 5 min before and 5, 10, 20, and 40 min after oral intake of 10‐ml volumes of the test solutions. The iron‐containing medicines differed with respect to pH (2.8–7.0), buffer capacity, viscosity, and iron content; two contained sorbitol (28 and 42%) and three sucrose (9, 17, and 47%). As expected, all sucrose‐containing preparations produced a significant decrease in pH, while no appreciable pH changes followed those with sorbitol. The pH readings after 5 min were affected by the sucrose content rather than the initial pH of the solutions. The decrease in pH was of shorter duration after exposure to the sucrose‐containing iron medicines than after the 50% aqueous sucrose solution.
Application of chlorhexidine by oral irrigation systems
Authors: AGERBAEK NINA , MELSEN BIRTE , RöLLA GUNNAR
Published: October 2007

abstract— Low concentrations of chlorhexidine (0.006%) were found to inhibit plaque formation when 750 ml was applied twice daily by oral irrigation systems. The procedure took 1–2 min and may be a convenient method of maintaining oral hygiene in patients in whom normal mechanical cleansing is difficult.
Caries frequency in children with controlled diabetes
Authors: MATSSON L. , KOCH G.
Published: October 2007

abstract— The frequency of caries was assessed in 33 diabetic children in whom the diabetes required insulin and dietary restriction and had been diagnosed before eruption of the permanent teeth. The frequency of caries and the number of erupted teeth were obtained from the dental records of the school dental service. Age‐ and sex‐matched non‐diabetic classmates served as controls. The mean number of DFS at the last dental examination of the diabetic children was 13.4, compared with 20.5 in the controls. The difference was largest in 12‐ to 14‐year‐old children, particularly in the premolar region, where the mean number of carious and filled surfaces in the diabetics was 2.6 compared with 5.9 in the controls. In all age groups, proximal carious lesions were less common in the diabetics than in the controls. No notable difference was found between the mean number of erupted teeth in the diabetics and that of the controls, except among the 12‐ to 14‐year‐old children. In that age group the diabetics had, on the average, 6.0 erupted premolars compared with 7.3 in the controls and 2.7 erupted permanent second molars compared with 3.5 in the controls. The results indicate that the dietary restriction observed by the diabetics had a favorable effect in promoting a lower caries frequency on all groups of teeth and on most tooth surfaces.
The effect of pH upon fluoride uptake in intact enamel
Authors: FRIBERGER PETTER
Published: October 2007

abstract— The relationship between pH and fluoride uptake in intact enamel of permanent premolars was investigated by using: (1) a sodium fluoride dentifrice, (2) a potassium fluoride+manganese chloride dentifrice, and (3) a sodium fluoride solution of the same fluoride concentration. The first part of this paper deals with the in vitro uptake of fluoride from dentifrice slurries and from sodium fluoride solutions of different pH ranging from 7.1 to 4.5. This investigation showed that there was no significant difference between the agents but that the effect of the pH was significant. The uptake of fluoride in the form of fluorapatite was more than five times larger at the lower pH level. The second part of the paper deals with the rate of fluoride uptake (increase in fluoride content) from dentifrices in the same pH range. It was shown that the three agents gave the same initial rate of fluoride uptake (about 50 parts/106/min) at pH 6 and that the rate of fluoride uptake in the outer layer of the enamel was proportional to the hydrogen ion activity.
Determination of inorganic pyrophosphatase in rat odontoblast layer by a radiochemical method
Authors: GRANSTRÖM GÖSTA , LINDE ANDERS
Published: October 2007

abstract— The enzyme inorganic pyrophosphatase (PPiase, EC 3.6.1.1) from the odontoblastic layer of rat incisors has been studied by means of a radiochemical micromethod. The enzyme was incubated with 32P‐pyrophosphate in tris‐HCl buffer at 37°C. The reaction was linear with time for at least 45 min, and the pH optimum was found to be 8.8, independent of the amount of pyrophosphate present. Heating the enzyme at 56°C inhibited the enzyme activity rapidly, Mg2+ ions activated the enzyme by 15% at an ion concentration of 4 mM, while higher concentrations were inhibitory. Ca2+ ions and PO43− ions inhibited the enzyme at all concentrations. F‐ ions did not affect the PPiase at concentrations below 8 mM, whereas higher concentrations had an inhibiting effect. Urea was found to inhibit the enzyme at concentrations above 1.5 M, while EDTA was a strong inhibitor at very low concentrations. The characteristics of PPiase agree well with the properties of the enzyme non‐specific alkaline phosphatase (EC 3.1.3.1.) studied earlier.
Bioluminescence assay of enzymes obtained from buccal epithelium by superficial scraping
Authors: HAMMAR H. , WETTERMARK G. , WLADIMIROFF W.
Published: October 2007

abstract— A method is presented for the simultaneous assay of buccal enzymes by measuring reduced nicotinamide adenine dinucleotide and adenosine triphosphate with the aid of the bioluminescence of luciferase extracts. The activity of glucose‐6‐phosphate dehydrogenase (G6PDH) was shown earlier to be increased in homogeneous leukoplakias of the oral mucosa. Since smoking has been implicated as an etiologic factor of leukoplakia, G6PDH was measured in the normal buccal epithelium of cigarette smokers. No difference was found in the activity of G6PDH between smokers and nonsmokers when related to the activity of pyruvate kinase, which is known to be invariable in healthy and leukoplakic oral mucosa. A new compact kinetic luminescence analyzer is briefly described.
Glycoproteins in fluid from non‐keratinizing jaw cysts
Authors: SKAUG N.
Published: October 2007

abstract – Fluid from 47 non‐keratinizing jaw cysts and autologous serum were separated by electrophoresis on cellulose acetate membranes and stained for glycoproteins. All cyst fluids contained glycoproteins, but the separation patterns differed from those of serum. The major carbohydrate‐bearing fractions of cyst fluid migrated with a2‐ and γ‐globulins, while in serum a2‐ and β‐glycoproteins contained most bound carbohydrates. The appearance of the γ‐globulin patterns indicated local synthesis and accumulation of cyst fluid γ‐globulins. The other glycoproteins most likely had escaped from plasma. Electrophoretograms of cyst fluid stained for glycosaminoglycans revealed that cystic glycoproteins often were complexed with glycosaminoglycans, causing more or less distorted separation patterns.
Distribution of cadmium in developing teeth and bone of young rats
Authors: BAWDEN JAMES W. , HAMMARSTROM LARS E.
Published: October 2007

abstract – 109Cadmium was injected intraperitoneally into 10‐d‐old rats. The rats were terminated at 1, 4, 24 and 96 h postinjection. Distribution of the tracer was studied by autoradiographic techniques, with particular attention directed to the dental tissues. Considerable accumulation of 109cadmium occurred in the cells of the enamel organ and to a lesser degree in the odontoblasts. Slight uptake of the tracer in the enamel and dentin was observed. The injected cadmium was also accumulated in the growing bone. Microautoradiography seemed to indicate that the isotope was preferentially localized in the osteoblasts.
The predominant cultivable organisms in juvenile periodontitis
Authors: SLOTS JÖRGEN
Published: October 2007

abstract— Quantitative and qualitative examinations of the predominant cultivable microflora of the advanced tissue destruction (pocket) associated with juvenile periodontitis and of control pockets without loss of attachment were carried out by using anaerobic tube culture technique. The microflora from the control sites consisted primarily of streptococci, Gram‐negative rods, and Gram‐positive rods. In contrast, the test pockets had a relatively stable and characteristic microflora, dominated by various Gram‐negative, anaerobic rods. The Gram‐negative rods were divided into main groups, but a satisfactory classification of many of these microorganisms could not be performed with the methods used and the data available. The predominating Gram‐negative rods differed from individual to individual. The role of the Gram‐negative rods in the etiology of juvenile periodontitis is unknown. Some potential pathogenic mechanisms of these microorganisms are discussed.
Effect of formaldehyde‐containing drugs on human dental pulp evaluated by enzyme histochemical technique
Authors: MEJARE INGEGERD , HASSELGREN GUNNAR , HAMMARSTROM LARS E.
Published: October 2007

abstract— The in vivo effect of formaldehyde on pulp tissue in short‐term studies cannot be established by using routine histologic techniques because the tissue is exposed to a fixative in vivo as well as during the histologic preparation. The pulps of permanent pre‐molars were amputated and zinc oxide with 4% formaldehyde or formocresol was used as wound dressing. The observation periods varied from 1 to 16 d. After extraction the teeth were freeze‐sectioned, freeze‐dried and then incubated for histochemical demonstration of some oxidative and hydrolytic enzymes. A demarcated border between apically stained and cervically nonstained pulp tissue was found in sections incubated for oxidative enzymes. When formocresol, which has a high concentration of formaldehyde, was used, the border was situated closer to the apex. This was also the case when the observation period was increased. The incubation for lactate dehydrogenase gave a high staining intensity. Thus the use of frozen sections in combination with the histochemical method for the demonstration of lactate dehydrogenase appears to be suitable for the study of the penetration of formaldehyde in pulp tissue in short‐term studies.
pH and the cytotoxicity of fluoride in an animal cell culture system
Authors: HELGELAND KRISTEN , LEIRSKAR JAKOB
Published: October 2007

abstract— To investigate the mechanism for the toxicity of silicate cement as observed in a cell culture system, the effects of pH and fluoride were tested on human epithelial cells (NCTC 2544). At pH 7.3, fluoride concentrations from 15 to 25 μg/ml (0.79 to 1.3 mM) had a growth inhibitory effect. When pH of the incubation medium was lowered in the range 7.0 to 6.4, an enhanced cytotoxic effect of fluoride was found, and even at 5 to 10 μg/ml growth inhibition occurred. Concomitant with the enhanced cytotoxicity of fluoride at low pH, there was an increased utilization of glucose and formation of lactate. Upon lowering the pH of the incubation medium from 7.4 to 6.7 a twofold increase in the intra‐cellular concentration of fluoride was found.
A 24‐month evaluation of fissure sealing with a diluted composite material
Authors: ULVESTAD HARALD
Published: October 2007

abstract— The idea of pit and fissure sealing has found wide acceptance in caries prevention. The present investigation evaluates the retention of a diluted composite material (Concise Enamel Bond system®) used as a pit and fissure sealant. On the basis of a clinical evaluation in 69 children of the retention of the material in pits and fissures for 24 months, it seems justified to assume that a diluted composite material is an acceptable alternative to other fissure‐sealing materials.
A radiographic study of mineralization of permanent teeth in a group of children aged 3—7 years
Authors: NIELSEN H. G. , RAVN J. J.
Published: October 2007

abstract— The purpose of the present study was, by using a standardized radiographic technique, to assess the time of selected mineralization stages of all permanent teeth except the second and third molars in a group of 580 children aged 3–7 years. A complete radio‐graphic examination, consisting of nine intraoral films, was made of each child, using Eggen's film holder. According to degree, mineralization of the teeth was subdivided into nine stages. The cap relation between the two variables, mineralization stage and chronologic age, was calculated by linear regression analysis. The hypothesis of the present study, that linearity exists between the two variables, was confirmed within and close to the investigated age group.
Phases in preamalgamated silver Samalgam alloy
Authors: JENSEN S. J. , VRIJHOEF M. M. A.
Published: October 2007

abstract— The phase content of six preamalgamated alloys available on the dental market has been determined by means of X‐ray diffraction. The β1‐phase was found in five alloys.
Sucking habits and occlusion in 3‐year‐old children
Authors: RAVN J. J.
Published: October 2007

abstract – The material for the present study comprises plaster models of 310 Copenhagen children, impressions for which were taken during the month each child attained the age of 3 years. The occlusion was related to information concerning the child's sucking habits up to the time of the study. The effect of sucking habits on sagittal occlusion was observed in the canine region and the molar region. A higher proportion of distal canine relationships was recorded in children who continued to suck dummies at the age of 3 years than among finger‐suckers or children who had never sucked. In the primary second molar region no significant difference was recorded between the various sucking groups. The open bite is clearly dominant among children who persist with a sucking habit.
Effectiveness of fissure sealant 3 years after application
Authors: MEURMAN J. H. , HELMINEN S. K. J.
Published: October 2007

abstract – Findings 3 years after the application of a fissure sealant revealed that of the 166 sealed permanent first molars, 7.8 % of the sealants were missing or partly missing, 14.5 % were in fair condition, and 77.8 % had remained in good condition. During the 3‐year test period, 7.8 % of the sealed permanent molars had become carious, while 63.3 % of the respective control teeth had decayed. The teeth which had sealants in good condition showed no caries, whereas 92.3 % of the teeth which had sealants missing or partly missing showed carious fissures. The net gain in the study was 104, and the percentage effectiveness of the method was 88.1 %. The treatment effect was found to be very significant when analyzed on the basis of homologous paired test‐control teeth (P < 0.001). The sealing of pits and fissures was found to have a positive treatment effect on 60.2 % of the subjects when evaluated on an individual basis (0.1 < P < 0.05).
Surface potential and adherence of oral streptococci to solid surfaces
Authors: OLSSON JAN , GLANTZ PER‐OLOF , KRASSE BO
Published: October 2007

abstract – Strains of oral streptococci belonging to the same species but with different ζ‐potential adhere with different strengths or become desorbed at different rates. However, strains of various species but with approximately the same ζ‐potential also adhere differently. The adherence was found to be affected by the presence of polyvalent counter ions in the suspending medium. This seemed to be related to a change in the surface potential of the microorganisms studied.
Influence of maturation status and tooth type of permanei teeth upon electrometric and thermal pulp testing
Authors: FULLING H.‐J. , ANDREASEN J. O.
Published: October 2007

abstract – The threshold values of developing teeth were determined for two commonly used electrometric pulp testers (Siemens sirotest® and Bofors Pulp Tester®) and a new thermal test based on carbon dioxide snow (Odontotest®). The teeth examined were divided into 7 stages according to maturation status. This study showed that teeth in Stages 3–5, i.e. until completion of root formation, show an increased electrometric threshold value. The Siemeans tester appeared to be equal to the Bofors tester with regard to reliability. The Odontotest was the most reliable method examined, giving a consistent positive response in all examined teeth.
Influence of splints and temporary crowns upon electric and thermal pulp‐testing procedures
Authors: FULLING H.‐J. , ANDREASEN J. O.
Published: October 2007

abstract – The influence of different splints and temporary crowns upon the reliability of electric and thermal pulp‐testing procedures was examined in 10 patients with vital maxillary central incisors and 10 patients with unilateral pulp necrosis of a central incisor. The pulp‐testing procedures were: (1) Bofors Pulp Tester®, (2) Siemens Sirotest®, (3) heated guttapercha, (4) ice, and (5) carbon dioxide snow (Odontotest®). The splints or temporary crowns were: (1) silver cap splint, (2) acrylic cap splint, (3) Hawley orthodontic plate, (4) Saur's arch bar, (5) orthodontic bands, (6) stainless steel crown, and (7) stainless steel crown with labial surface removed. A reliable electrometric pulp response could only be elicited if the pulp tester was applied directly upon enamel and preferably upon the incisal edge. In this instance metal splints or partial steel crowns applied to the tooth had no effect on the pain threshold. A false positive reaction in case of pulp necrosis was only elicited when the electrode was placed directly upon metal which contacted neighboring vital teeth. The use of ice and heated guttapercha appeared to be of limited value, due to inconsistent pulp responses. Carbon dioxide snow gave a reliable response, unless applied on the incisal edge.
Intraoral spread of the antimicrobial effect of a chlorhexidine gel
Authors: SAXÉN LEENA , NIEMI MAIJA‐LIISA , AINAMO JUKKA
Published: October 2007

abstract – The, aim of the study was to determine the range of the antimicrobial effect of Hibitane Dental Gel® (ICI, Macclesfield, England), containing 1 % chlorhexidine, when used as a dentifrice while brushing. A standard toothpaste with no claim for antibacterial activity (Pepsodent®) was used as a control. Twenty‐four dental students brushed their teeth during two 4‐day periods using the closed mouth technique, i.e. they kept their teeth tightly clenched and brushed only the facial tooth surfaces twice daily. Before and after each test period the lingual and linguomesial surfaces of the mandibular teeth were scored for clearly visible plaque. The facially applied chlorhexidine gel had no more effect on plaque growth lingually than the standard toothpaste which was used as control. The lack of effect of the gel was suggested to be due to an insufficient spread and penetration capacity of its antimicrobial component.
Clinical evaluation of amalgam restorations
Authors: MJÖR IVAR A. , HAUGEN ELLEN
Published: October 2007

abstract – The good reproducibility of a clinical evaluation system for restorations was confirmed, but the system was not considered suitable for detection of minor differences between amalgam restorations. A modified system for evaluation was therefore developed. It was based on the same principles but included more characteristics. The modified system was evaluated in practice on 246 amalgam restorations. The level of agreement between two examiners reached about 70 % after an initial training period. The results demonstrate the need for calibration of examiners and the importance of a detailed definition of criteria.
Root caries: distribution and uptake of elements in lesions adjacent to silicate or amalgam restorations
Authors: HALS EINAR
Published: October 2007

abstract – In carious lesions adjacent to silicate or amalgam restorations outer lesions of the cementum showed the same content and distribution of Ca, P, Mg, and S as did primary lesions in this area, but differed from these in having an increased content of Zn., Al, and probably F (silicate cases) and Zn, Sn, and Cu (amalgam cases). The cementum walls showed an uptake of ions largely similar to that previously described in dentinal walls.
Antimicrobial effect of four different toothpastes
Authors: SJÖBLOM MONICA , AINAMO ANJA , AINAMO JUKKA
Published: October 2007

abstract – The study was undertaken to evaluate the antimicrobial effect of a commercial toothpaste, claimed to contain active chlorhexidine gluconate. Two traditional toothpastes and a 0.5 % chlorhexidine gel were used as negative and positive control pastes. To exclude the effect of mechanical cleaning, all the agents were applied twice daily to the tooth surfaces by means of individually constructed acrylic cap splints. Ten dental students used each paste in a 4‐week cross‐over double‐blind study comprising four test periods of 4 d duration. The students were allowed normal mechanical oral hygiene during the 3 d between the test periods. At the beginning and the end of each test period the tooth surfaces in the right halves of the jaws were scored for the Plaque Index, after which disclosing solution was used and the teeth of the left halves of the jaws were scored for stained plaque. Of all the toothpastes tested, only the chlorhexidine gel exhibited an antimicrobial effect comparable to that of efficient mechanical oral hygiene measures. The effect of the toothpaste with claimed chlorhexidine content did not differ from that of the two traditional toothpastes.
Pulpal reactions to surface‐sealed silicate cement and composite resin restorations
Authors: SKOGEDAL OLE , ERIKSEN HARALD M.
Published: October 2007

abstract – The effect of surface sealing and presence of bacteria in connection with pulpal response to silicate cement and composite resin restorations was tested in monkey teeth. Surface‐sealing of silicates reduced the pulpal reactions to this material, whereas no such effect was observed when composites were sealed. Bacteria regularly occurred on the cavity walls except underneath zinc oxide/eugenol (ZOE) fillings and when silicates were sealed with ZOE. The frequency of bacteria was higher in teeth with unacceptable pulpal responses (44 of 49) than in teeth with acceptable reactions (48 of 79).