bluuebunny/crossref_metadata_2025 huggingface dataset:
Periodontopathic bacteria and salivary microbes before and after extraction of partly erupted third molars
Authors: Rajasuo Ari , Meurmarr Jukka H. , Murtomaa Heikki
Published: October 2007

This study examines the effect of extraction of third molars on suspected periodontopathogenic microbes, salivary acidogenic bacteria, and yeasts. The subjects were 39 healthy conscripts aged 20.2 yr, with symptom‐free, partly erupted mandibular third molars. Microbial samples were taken from the mandibular third molar pericoronal space and from the adjacent gingival pocket of the second molar. The samples were stained by Gram's and Giemsa's methods and studied under a light microscope. Stimulated saliva was collected for assessing mutans streptococci, lactobacilli, and yeast counts by chair‐side kits. All partly erupted third molars were extracted from 20 test subjects; 19 control subjects were left untreated. Microbial samplings were repeated 2 and 5 months postoperatively. Results showed that at base line the total number of Gram‐negative bacteria, Gram‐negative rods, and spirochetes was significantly higher at the third molar than at the second molar sites. The extraction of the third molars caused a significant decrease in the percentage of these bacteria at the second molar sites. High counts of salivary mutans streptococci (CFU≥106) and lactobacilli (CFU ≥ 105) were also significantly less frequent after the operations. Yeast counts were not affected by the extractions. Thus, partly erupted third molars may harbor a periodontally pathogenic microflora and increase the number of salivary acidogenic microbes.
Epithelial α‐naphthyl acetate esterases in the green vervet monkey gingiva before and after periodontal surgery and during tooth eruption
Authors: Juhl M. , Holmstrup P.
Published: October 2007

To provide enzymatic information on de novo formed junctional (JE) and sulcular epithelium (SE), we performed periodontal surgery on 24 teeth. Ten to 14 days postoperatively, all experimental and 16 control teeth were extracted with adjacent buccal gingiva. In addition, specimens from unerupted and partly erupted teeth containing enamel epithelium (EE) were examined. Fixed cryostat sections were cut in series, stained with HE, or incubated with and without substrate for demonstration of α‐naphthyl acetate esterase activity and for control purposes, respectively. The distribution and intensity of the α‐naphthyl acetate esterase activity of newly reformed JE and SE was identical to that of the original JE and SE, i.e. suprabasal and very strong. In contrast, both the oral gingival epithelium (OGE) and the EE displayed a very weak enzyme reaction. These observations indicate that the presence of α‐naphthyl acetate activity of original and reformed JE and SE is probably site specific and of nondevelopmental origin. Heavy inflammation after healing was associated with enhanced epithelial proliferation of OGE and, in addition, marked esterase activity of these proliferations and corresponding OGE. This points at a possible inflammatory induction of the marked esterase activity seen in JE and SE as well as site‐specific, connective tissue influences. Further investigation is needed to elucidate the effect of inflammation on the esterase activity.
Prediction of behavior‐management problems in 3‐year‐old children
Authors: Holst Annalena , Hallonsten Anna‐Lena , Schröder Ulla , Ek Lars , Edlund Karin
Published: October 2007

The aim was to determine power of nondental background factors to predict behavior‐management problems at the first dental visits of 3‐yr‐old children. A total of 273 children from three kinds of residential area – city, town, and rural area – in Sweden took part. The parents were interviewed before the child's dental visit. The behavior of the child was rated by registering the degree of acceptance according to the method of Holst & Crossner. The following steps were rated: entering the dental treatment room, mirror in mouth, probe on fingernail and tooth, air‐blower on hand and in mouth, sitting in the dental chair, and examination. The behavior was then analyzed in relation to the answers of the interviews, and a logistic regression model was used to calculate the power of the variables, separately or combined, to predict behavior‐management problems. Seventy‐six percent of the children cooperated well at the dental examination; 13% reacted reluctantly, and 11% reacted negatively. Two interview variables had statistically significant predictive power: the parent's expectation of a negative reaction from the child in the dental situation and the child's anxiety when meeting unfamiliar people. Sixty‐nine percent of child patients accepted the examination while sitting alone in the chair. Sitting alone used as a predictor for cooperation showed sensitivity 0.80, specificity 0.71, predictive value for positive test 0.44, and predictive value for negative test 0.94.
Reliay of three dental radiometers
Authors: Hansen Erik Keith , Asmussen Erik
Published: October 2007

The light intensity from 80 different curing units was recorded on three dental radiometers. Even though the correlation between the recordings obtained with the three testers was rather high, some units were categorized as good units by one radiometer and poor ones by another. It was also found that, in some case, there was a pronounced difference between the output within the same type of new units. Cavities were made in extracted third molars, filled with a microfilled resin, irradiated for 40 s with 20 of the curing units, and the depth of cure was measured. The radiometers were not able to rank the 20 units in accordance with their depth of cure. We conclude that the three radiometers are not fully reliable. However, they may become very useful tools for monitoring the output from a curing unit if the radiometer and the unit are calibrated.
Thermogravimetric studies on sound and carious human enamel and dentin as well as hydroxyapatite
Authors: Larmas Markku Antero , Häyrynen Hannu , Lajunen Lauri HJ
Published: October 2007

The present study was conducted to investigate the thermal behavior of human sound and carious enamel and dentin. The results were compared to those obtained for pure hydroxyapatite. The volatile decomposition products were identified by mass spectrometry. Solid decomposition products were analyzed by infrared (IR) spectrometry. For both normal and carious enamel, the differential thermogravimetry (DTG) curves revealed three peaks at about 90–100, 330, and 900°C. Both normal and carious dentin revealed two common peaks in their DTG curves, at about 90–100 C and 330°C. An additional peak at 500–600°C was observed in the DTG curve of carious dentin in air atmosphere. This peak completely disappeared in nitrogen (N2) atmosphere. About 11–12% of sound and carious enamel was volatilized in air. The values for sound dentin were 34% and for carious dentin 54% per weight, respectively. Enamel and dentin (apatite protein complex) decomposed at higher temperatures than pure hydroxyapatite in air. In N2 atmosphere, both enamel and dentin are more resistant to thermal decomposition than in air, because organic materials decompose easier in an oxidizing atmosphere than in an inert atmosphere.
Effect on human teeth of renal transplantation: a postmortem study
Authors: Näsström Karin , Möller Bengt , Petersson Arne
Published: October 2007

Extracted teeth from five deceased patients treated by renal transplantation were examined radiographically and histologically, and compared with teeth from healthy persons of approximately the same age. In three of the patients with a renal transplant, the radiographs showed normal pulp chamber sizes, but histologic examination revealed a widened predentin zone, approximately four times greater than in the controls. In two of the patients the radiographs showed marked reduction of the pulp chamber size. The histologic changes of these teeth were mainly an extensive amount of secondary dentin along the pulp chamber walls and the root canals, with a markedly reduced pulp space. One explanation for the difference between the patients was that patients with extensive pulp calcifications were given a higher total amount of corticosteroids than patients with a widened predentin zone.
A modified device for collection and flow‐rate measurement of submandibular‐sublingual saliva
Authors: Nederfors Tommy , Dahlöf Carl
Published: October 2007

The aims of the present study were to measure stimulated submandibular‐sublingual (SM‐SL) salivary flow rate with a modified Block‐Brottman collection device, and, further, to evaluate the reliability of measurements of stimulated SM‐SL salivary flow rate by means of this modified Block‐Brottman device, as compared to measurements of parotid flow rate using modified Carlson‐Crittenden cups. Twenty‐nine healthy female volunteers, aged 36±7 yr, were included. Saliva stimulation was achieved by application of a 3% citric acid solution to the rims of the tongue four times/min, for 3 s every 15 s. On 3 consecutive days, stimulated parotid and SM‐SL salivas were collected for 2 min at 07.30, before breakfast (morning value), and at 10.00, 2 h after a standard breakfast (lunchtime values). SM‐SL saliva was also collected on one occasion for 2 min ± 3. For parotid and SM‐SL saliva, the mean stimulated flow rates were in the morning, 1.50±0.83 and 2.25±1.12 ml/min, and at lunchtime, 1.71±1.16 and 2.54±1.01 ml/min, respectively. For both salivas, lunchtime values were significantly higher than morning values by about 13–14%. Comparing parotid and SM‐SL saliva flow rates, we found the SM‐SL saliva flow rate to exceed the parotid flow rate by about 50% both in the morning and at lunchtime. Variations in flow rate were analyzed by means of ANOVA. Interindividual variance and variance between measurement days and times of day made up 88% of parotid and 83% of SM‐SL total variance. By calculating the variation coefficient, we found this to be smaller for SM‐SL salivary flow rate measurements as compared to parotid flow rate measurements. In conclusion, the results of the present study indicate that our method of collecting stimulated submandibular‐sublingual saliva by means of a modified Block‐Brottman collection device is as reliable as the method of collecting stimulated parotid saliva by means of modified Carlson‐Crittenden cups, and is thus a useful method for future studies of changes in submandibular‐sublingual salivary production.
Clinical study of oral galvanism: no evidence of toxic mercury exposure but anxiety disorder an important background factor
Authors: Herrström Per , Högstedt Benkt
Published: October 2007

A total of 142 women and 76 men with self‐diagnosed oral galvanism who were referred from dentists and medical doctors for clinical evaluation during the last 2 yr are described from the perspective of general medicine. No case of clinically suspected mercury intoxication was found. Mean concentration of mercury in whole blood (B‐Hg) was 17.3 nmol/1, and no value exceeded 50 nmol/1. Amalgam burden and B‐Hg were not associated with clinical signs or symptoms except for a significantly lower mean value of B‐Hg in patients with psychologic main symptoms than in those without (mean 15.4 vs. 18.1 nmol/1). It was possible to make one or several diagnoses in all 218 cases as reasonable alternatives to the concept of oral galvanism. Mental disorder was the main diagnosis in 93 cases (42.7%), including 41 cases of generalized anxiety disorder and 12 cases of panic disorder. A total of 87 patients (40%) did not work because of medical reasons or unemployment. Amalgam removal was recommended in a total of 65 cases (29%), mainly on psychologic indications, but in 22 cases because of oral conditions. The clinical conditions behind the concept of oral galvanism seem to be explicable in terms of general medicine, and no generalized toxic effect of amalgam fillings need be suspected.
Nordic dentists' opinions on the safety of amalgam and other dental restorative materials
Authors: Widström Eeva , Haugejorden Ola , Sundberg Hans , Birn Herluf
Published: October 2007

The safety of amalgam and other restorative materials has caused concern among dental patients in recent years. The aim of this study was to obtain information on dentists' perceived competence in handling different filling materials and their opinions on the safety of these. A random sample of practising dentists in Denmark, Finland, Norway, and Sweden received a mail question‐naire in spring 1990. Answers were received from 1732 dentists (65%). The study showed that the respondents believed that their theoretic knowledge and clinical skills were generally at a high level regarding restorative materials. The risks of the side‐effects of gold, ceramic materials, and glass ionomer were considered to be low by about 90% of the respondents. Amalgam was considered to be significantly more hazardous by the Swedish respondents than the others. Interestingly, composite was considered to be associated with a high risk of side‐effects by about half of the dentists in all Nordic countries. The dentists' opinions were not found to be greatly influenced by their sex, age, or place of residence but rather by their country and service sector. Against the background of the present lack of scientific evidence on the hazardousness of amalgam or other restorative materials for patients' general health, these findings indicate that dentists are influenced by discussions in the mass media about dental treatment and materials and, of course, by the guidelines given by the health authorities in their own countries. Few dentists were shown to be concerned about occupational risks associated with the use of amalgam, and they had not had their own amalgam fillings replaced. Thus, Nordic dentists seem prepared to continue to use amalgam as one of several dental restorative materials while waiting for technically and biologically more satisfactory ones.
Evaluation of three silicoating methods for resin‐bonded prostheses
Authors: Hansson Ola , Moberg Lars‐Erik
Published: October 2007

Three different methods of increasing the bond strength of resin to metal were tested: the original Silicoater technique, the Silicoater MD technique, and the Rocatec system. Metals used for the resin‐bonded prostheses were gold, a cobalt‐chromium (Co‐Cr) alloy, and titanium. Silicoating increased the bond strength to sandblasted specimens. The original Silicoater technique produced the highest bond strengths, especially when used with the Co‐Cr alloy and titanium. The Silicoater MD technique showed the lowest bond strengths for all of the test metals. Storage for 7 days with protective film on the silicoated surface did not affect the bond strength, as compared with specimens bonded immediately. The retention of the resin to the gold specimens (Rocatec system) decreased after thermocycling, but retention to the Co‐Cr alloy and titanium was not affected. Various resin cements were tested and showed the same retention with the exception of Microfill Pontic, which gave a weaker bond. Scanning electron microscope (SEM) and energy‐dispersive X‐ray analysis (EDAX) of the specimens before and after the measurements gave no clear explanation of the differences in bond strengths between the test metals. However, it was concluded that silicoating of the metal surfaces contributed to the retention of the resin by chemical action, as no differences in adaptation of the resin to the metal were seen between specimens pretreated by sandblasting and those which were also silicoated.
Crown retention and cyclic loading (in vitro)
Authors: Gundler Agneta , Lockowandt Paul , Erhardson Svante
Published: October 2007

Cast gold crowns were luted on extracted and prepared human teeth with zinc phosphate cement and subjected to a fatigue test by cyclic loading. The correlation between crown retention and three retention variables was determined by the fatigue test. The results show that the smallest convergence angle tested, 20°, gave better retention than did angles of 40° and 60°, and that surface roughness, surface size, height, and base diameter of the preparations had no influence on crown retention within the parameter sizes tested.
Dentin formation in miniature pigs with special reference to indomethacin and orthodontic treatment
Authors: Giunta Daniela , Keller Johnny , Nielsen Frank Farsö , Melsen Birthe
Published: October 2007

The rate of dentin mineralization and the influence of indomethacin on the dentin mineralization rate during orthodontic treatment was determined in miniature pigs by intravital labeling with tetracycline. The results demonstrated that the dentin mineralization rate in the control animals was 3.8 μm/day, a rate corresponding to that of human teeth. Both indomethacin and orthodontics had an effect on the dentin mineralization rate, indomethacin reducing and orthodontic forces increasing it. In combination, the two factors neutralized each other.
Exaggerated abrasion/erosion of human dental enamel surfaces: a case report
Authors: Westergaard Jytte , Moe Dennis , Pallesen Ulla , Holmen Lisbeth
Published: October 2007

An atypical, rapidly proceeding abrasion/erosion of the labial enamel surfaces of the maxillary and mandibular incisors and canines in a 27‐yr‐old man is reported. Ultrastructural examination of a replica of the teeth showed a practically structureless enamel surface both at the initial examination and after 12 months. However, at the end of the period, minor areas of dentin tubules became visible, indicating that a substantial loss of the tooth substance had taken place. The patient's occupation involved daily environmental contact with proteolytic enzymes. In vitro study of enamel exposed to one of the actual proteolytic enzymes showed dissolution of enamel substance, and it cannot be excluded that enzymatic decomposition of the organic enamel matrix is a contributing cause of the observed exaggerated loss of tooth substance.
Effectiveness of caries removal by the partial tunnel preparation method
Authors: Strand Gunhild Vesterhus , Tveit Anne Björg
Published: October 2007

The tunnel preparation method is designed to remove approximal caries through a channel from the occlusal surface while preserving the marginal ridge. This method entails reduced access to the caries lesion and thereby uncertainty as to the complete removal of caries. The purpose of the present investigation was to study the effectiveness of caries removal in 60 extracted premolars and molars by the partial tunnel preparation method. The glass polyalkenoat (ionomer) filling and the distance to the pulp were also examined. Examination of the sectioned teeth showed residual caries in the axial wall of two teeth and in dentin close to the enamel lesion in 10 teeth. Very few porosities were found within the glass polyalkenoat material and at the interface between the filling and the cavity walls.
Salivary fluoride clearance after a single intake of fluoride tablets and chewing gums in children, adults, and dry mouth patients
Authors: Sjögren Karin , Birkhed Dowen , Persson Leif G. , Norén Jörgen G.
Published: October 2007

The aim of the present investigation was to compare the clearance pattern in saliva and the salivary stimulating effect of a new fluoride (F) chewing gum (Fluorette) with three other F products used in Scandinavia for many years for caries prevention. Concentration of F was determined in whole saliva in three groups of subjects: 1) children, 10–12 yr of age (n= 20), 2) adults (n= 20), and 3) dry mouth patients (n= 15), after a single intake of the two tablets, Dentan and Fludent, and the two chewing gums, Fluomin and Fluorette, all containing 0.25 mg F as NaF. Sucking was allowed until the tablets had been completely dissolved in the mouth. The chewing gums were used for 15 min. Saliva samples were collected from subjects expectorating 0.3–0.5 ml at nine different time intervals up to 45 min after the intake. There were some significant differences in the maximum F concentration, the area under the salivary fluoride concentration curve (AUC) when plotted against time, and the salivary stimulating effect among the four products, but as a whole they were small and probably of minor clinical importance. Among the various groups, the dry mouth patients showed the highest salivary F concentration. Thus, the main conclusion from this study is that the F tablets and chewing gums studied, including the new product Fluorette, had approximately the same clearance pattern in saliva and the same salivary stimulating effect. However, there were great variations among the different subjects.
Presence of mast cells in various oral mucosal sites in juvenile and adult rats
Authors: Matsson Lars
Published: October 2007

The present investigation was designed to study the number of mast cells in various oral mucosal sites in juvenile and adult rats, with special reference to presence of subtypes of mast cells. Fifteen juvenile (1‐month‐old) and 15 adult (6‐month‐old) rats were used. Biopsies were taken from tongue, bucca, marginal gingiva (incisor area), and intestine (jejunum). For optimal preservation of the stainability of subtypes of mast cells, a fixative with low aldehyde concentration and low pH was used. The biopsies were embedded in paraffinwax. The first of three consecutive sections (5 μ) was stained in toluidine blue for 30 s, the second in toluidine blue for 7 days, and the third in astra blue/safranine. The total number of mast cells was represented by all cells positive to toluidine blue after 7 days' staining, or the sum of cells positive to astra blue and safranine. Cells positive to toluidine blue after 30 s were classified as connective tissue mast cells (CTMCs), and those positive after 7 days, but not after 30 s, as mucosal mast cells (MMCs). Cells positive to safranine in the astra blue/safranine staining sequence were classified as CTMCs, and those positive to astra blue as MMCs. Cells with intermediate staining characteristics in the astra blue/safranine staining sequence were recorded separately. The total number of mast cells in the tongue, buccal mucosa, and gingival mucosa was significantly higher in the juvenile than in the adult rats. In the buccal and gingival mucosa, more than twice as many mast cells were found in the young animals. In the intestine, however, the juvenile rats showed a significantly lower number of mast cells. In general, a higher number of cells with histochemical characteristics similar to the MMCs of the intestine was found in the oral sites of the juvenile animals. The differences in the total number of mast cells and the different composition of the mast cell population in the two age groups may indicate an age‐related difference in the potential for biologic reactions involving mast cells.
Reflectometry: a new method for quantitative determinations of intraoral film formation
Authors: Vassilakos Nikolaos , Glantz Per‐Olof , Arnebrant Thomas
Published: October 2007

A simple optical method ‐ reflectometry ‐ is described to determine the thickness and mass of salivary films formed on solid surfaces at oral exposure. Reflectometry is based on the fact that p‐polarized light is reflected with minimum intensity at an interface when the angle of incidence equals the so‐called pseudo‐Brewster angle. Hydrophilic and hydrophobized silica surfaces were used as substrates and the reflectometer was calibrated against a null ellipsometer. A linear relation was found between the square of the ellipsometrically measured thickness of silicon oxides on silicon substrates and the reflectometrically registered intensity of the reflected light at these surfaces. Thirty volunteers participated in the study of the thickness of films formed on the test substrates at oral exposure. The test silica surfaces were positioned in the vestibular sulcus of each test subject for periods of 1, 5, 15, 30, 60, and 120 min. The results show that films formed on hydrophobic surfaces leveled‐off to a thickness value of 140 Å after 60 min. Films formed on hydrophilic surfaces, however, reached a plateau value of approximately 100 Å after only 300 min. Reflectometry seems to be an accurate and valid, yet inexpensive and quick method for quantitative investigations and thickness measurements of early salivary pellicles in large subject groups.
Polymorphonuclear leukocyte chemiluminescence induced by Actinobacillus actinomycetemcomitans and Haemophilus aphrophilus in serum and saliva
Authors: Holm Anders , Kalfas Sotirios
Published: October 2007

The ability of different strains of Actinobacillus actinomycetemcomitans (A.a.) and Haemophilus aphrophilus (H.a.) to trigger activation of an oxidative burst in human polymorphonuclear leukocytes (PMNL) was examined by measuring the luminol‐amplified light emission ‐ chemiluminescence (CL) ‐ from these cells. Bacterial cells were incubated with PMNL from one healthy subject, in the presence of either active serum, heat‐inactivated serum, saliva, or saliva and active serum. In the presence of active serum, all five H.a. strains and two out of five A.a. strains triggered a CL response. The CL induced in the presence of heat‐inactivated serum was considerably less than that achieved with fresh serum. In the presence of only saliva, all strains induced considerably weaker CL responses than those induced in the presence of saliva with active serum. In the presence of serum, intracellular reactions appeared to be the main source of CL, while addition of saliva and active serum increased the extracellular CL. The results indicate that strain‐dependent differences exist among A.a. strains in their ability to trigger the oxygen‐dependent bactericidal mechanisms of human PNML. In contrast, the CL patterns of H.a. strains were equivalent. Various factors in the environment, such as activated complement and salivary compounds, affect the interaction of these species with neutrophils.
DNA probe detection of periodontopathogens in advanced periodontitis
Authors: Söder Per‐Östen , Jin Li Jian , Söder Birgitta
Published: October 2007

Species‐specific DNA probes were used to determine the presence of Actinobacillus actinomycetemcomitans (A.a.), Porphyromonas (Bacteroides) gingivalis, Prevotella intermedia, Treponema denticola. Eikenella corrodens, Fusobacterium nucleatum, and Wolinella recta in subgingival plaque from deep pockets/sites of patients with advanced periodontitis. The subjects were 20 patients with severe adult periodontitis, 13 men and 7 women (mean age 45.6 ± 6.7 yr). For each subject, 9–10 subgingival sites with the deepest probing depths from each quadrant were sampled by the paper point method, a total of 198 sites, with mean probing depth 7.2 ± 1.6 mm and clinical attachment level 9.5 ± 2.7 mm. A.a. was present in at least one site in 75% of the subjects; P. gingivalis was found in 95%; P. intermedia and W. recta were found in 90%, respectively; and T. denticola, E. corrodens, and F. nucleatum were found in all subjects. In the 198 samples, A.a. was detected in 25.8%, P. gingivalis in 51.5%, P. intermedia in 64.1%, T. denticola in 60.6%, E. corrodens in 72.9%, F. nucleatum in 74.7%, and W. recta in 65.7%. The predominant combination was the simultaneous presence of P. intermedia, T. denticola, E. corrodens, F. nucleatum, and W. recta in 89.5% of the subjects and 46.8% of the sites. Of these sites, 51.1% showed the combined presence of P. gingivalis and 28.4% that of both A.a. and P. gingivalis. None of the seven bacteria could be detected in 14.4% of the total sites sampled. The present study indicates that severe destructive adult periodontitis is a multibacterial infection and that certain combinations of periodontopathogens seein to be important in the pathogenesis of the disease.
Miconazole chewing gum for treatment of chronic oral candidosis
Authors: Rindum Judith L. , Holmstrup Palle , Pedersen Morten , Rassing Margrethe R. , Stoltze Kaj
Published: October 2007

A chewing gum containing the antifungal drug miconazole may be convenient for topical treatment of oral candidosis. Therefore a trial was performed to examine the effect and tolerance of miconazole chewing gum in comparison with miconazole gel in the treatment of oral candidosis. The study group consisted of 32 patients with oral candidosis harboring yeasts, predominantly Candida spp. Half of the patients chewed one piece of chewing gum (dose: 3.6 mg of miconazole) four times daily; the other half dispersed a 2% gel (dose: 50 mg of miconazole) in the oral cavity four times daily. After 6 wk of treatment, there was no clinical evidence of yeast infection in either of the two groups. No significant differences between the two groups were found in clinical, mycologic, and cytologic investigations conducted after 3 and 6 wk of treatment or at the follow‐up examination 4 wk after termination of the treatment. The results indicate that miconazole released from chewing gum is as effective as miconazole gel. The chewing gum reduced the dosage of miconazole for treatment of oral candidosis, and the patients approved the chewing gum as a pleasant medicament.
Maximal contraction force and endurance of human jaw‐closing muscles in isometric clenching
Authors: Waltimo Antti , Kemppainen Pentti , Könönen Mauno
Published: October 2007

Maximal unilateral bite force and endurance times from maximal bite force to the 75% and 50% levels of maximal values were recorded for 13 men and 15 women with bite openings of 10 and 14 mm. Measurements were made both from right and left molar regions and from the incisal region. Bite force values were significantly higher than previously measured in endurance tests by devices with unilateral housings. Men achieved greater bite force than women in the molar region in every trial. The general assumption that women's muscles are superior to those of men in static endurance when both are working at the same percentage of maximal voluntary contraction was not supported by this work for jaw‐closing muscles. The endurance times to 75% and 50% levels of maximal bite force were shorter than could be expected from previous reports, and endurance times to the 50% level were even shorter than those reported for muscles of limbs.
Mercury in primary teeth in preindustrial Norway
Authors: Eide Rune , Wesenberg Gro R. , Fosse Gisle
Published: October 2007

Seventy‐nine primary (deciduous) teeth were excavated in 1978 underneath the floor of the stave church in Uvdal, Buskerud County, Norway. The mercury content of 57 teeth was measured by means of cold vapor atomic absorption spectrophotometry. As a comparison, 124 primary teeth from modern Norway were analyzed. A significant statistical difference was found between the two sets of material. In the Uvdal material a correlation was found between the mercury and copper contents. For the modern material a correlation was found between mercury and lead, and between mercury and zinc. The authors maintain that the values found for the Uvdal material represent base‐line values for mercury in primary teeth, and probably reflect uptake from natural environmental sources only. Furthermore, these values may be used for reference in studies of other preindustrial, as well as modern, primary teeth. Our findings also indicate a higher level of mercury in modern than in preindustrial primary teeth in Norway.
Characterization of fibronectin and fibrin(ogen) fragments in gingival crevicular fluid
Authors: Talonpoika J. T. , Söderling E. , Paunio K.
Published: October 2007

A total of 49 crevicular fluid (CF) samples were collected with paper strips from 12 healthy adults. Each sample was eluted into sterile saline and two aliquots were drawn for SDS–PAGE, one for fibronectin and one for fibrin analysis. Peptides were transferred to nitrocellulose membranes, and fibronectin and fibrin were detected using specific antibodies. The relative amounts of different molecular forms of fibronectin and fibrin were analyzed using a laser densitometer. After the sample collection, Plaque Index, Papilla Bleeding Index and pocket depth were measured. Bone loss was estimated from the orthopantho‐mograms. Fibronectin fragments were seen in all CF samples. Intact fibronectin was seen in 21 samples, of which 76% were collected from periodontitis‐affected sites. There was a positive correlation between the proportion of intact fibronectin and the clinical parameters. Intact fibrin and fibrin fragments were seen in all samples. Fibrin‐positive material with larger molecular weight than intact fibrin was also seen in all samples. A negative correlation was found between the proportion of intact fibrin and the clinical parameters. There was no correlation between total amounts and concentrations of fibronectin and fibrin. Molecular forms of fibronectin and fibrin may affect the pathogenesis and healing of periodontal diseases, since the biologic effects of the fragments of these molecules differ from those of the intact molecules.
Salivary stimulation by chewing gum and lozenges in rheumatic patients with xerostomia
Authors: Risheim Helge , Arneberg Pål
Published: October 2007

The effect of chewing gum and lozenges in relieving the signs and symptoms of xerostomia was studied in a 2‐wk cross‐over clinical trial in 18 rheumatic patients with dry mouth symptoms and low salivary flow rates. Resting flow was measured before (PRESTIM) a chewing stimulated flow rate test (STIM), and also 5 min after (POSTSTIM). STIM flow (mean 1.0 ml/min) was not affected by the test regimens. In the lozenge regimen, mean PRESTIM flow in the group increased from 0.11 to 0.14 ml/min and POSTSTIM from 0.10 to 0.13. In the chewing gum regimen, PRESTIM flow (mean 0.13 ml/min) did not change, whereas POSTSTIM flow increased from 0.13 to 0.16 ml/min. In terms of patients' preferences, chewing gum and lozenges were ranked equal. Both these physiologic stimuli had few side‐effects. Subjective symptoms were relieved in about one‐third of the subjects, but relief was not always verified by improved flow rates. The regimens were not found to influence buffering capacity; salivary counts of mutans streptococci, lactobacilli, and Candida; or oral sugar clearance time.
Radiographic screening examination: frequency, equipment, and film in general dental practice in Denmark
Authors: Hintze Hanne
Published: October 2007

The aim of the present study was to evaluate types and frequencies of radiographic screening examinations, and radiographic equipment and film used in general dental practice in Denmark. A questionnaire was mailed to 400 randomly selected dental practitioners. A total of 258 questionnaires were returned, out of which 249 were analyzed. Two‐thirds of the respondents performed radiographic screening examinations, of which bitewing‐screening was the one most frequently used for first‐visit and regular patients. The more recent their graduation year, the more apt were dentists to perform radiographic screening examinations. More than 40% of the dentists had radiographic units operating at a voltage capacity of 60–70 kV, and more than 50% had facilities for automatic or semiautomatic processing. Only one‐quarter of the respondents used the Kodak Ektaspeed film (E‐speed film). The results show that radiographic procedures and film used in general dental practice are not always in accordance with guidelines and recommendations.
Histochemical characterization of pig masseter muscle: an animal model
Authors: Tuxen Anette , Rostrup Egill
Published: October 2007

Masseter muscle autopsies were obtained from six different areas of six pigs. The autopsies were stained for the demonstration of myosin ATPase activity by means of a conventional histochemical technique. As compared with human masseter, the pig masseter muscle contained more type II fibers. But, like the human masseterMasseter muscle autopsies were obtained from six different areas of six pigs. The autopsies were stained, the pig muscle had a varying distribution of fiber types in the different autopsy areas, a distribution which might be the result of an adaptation to carry out special functions such as chewing, swallowing, and jaw posture. The fiber type distribution in the pig masseter also varied among individuals, probably reflecting various levels of utilization of the muscles besides different genetic influences. Moreover, pig masseter contained fibers of intermediate staining intensity (IM fibers), a fiber type rarely seen except in human masticatory muscles. In conclusion, we consider the pig masseter to be a useful animal model to study muscular adaptations to altered function in the orofacial region.
Social indicators of dental caries among Sierra Leonean schoolchildren
Authors: Nörmark Sten
Published: October 2007

Most of the caries of African child populations is found in limited fractions of that population. The purpose of the present study was to analyze the caries situation of Sierra Leonean schoolchildren in relation to demographic, socioeconomic, and behavioral variables, in order to develop an appropriate index for prediction of caries. A total of 610 students from primary class 1 (mean age: 7 yr) and secondary form 1 (mean age 15 yr) were dentally examined by three examiners and interviewed by their teachers. Intra‐ and interexaminer reproducibilities were 82 and 70%, and interinterviewer reliability was 67–100% for the individual questions. Urban students had more caries than rural. In class 1, dmfs + DMFS was 4.1 and 1.8, respectively; in form 1, DMFS was 5.3 and 3.5. Two tribes (the Fulas and the Madingos) had higher caries means than the rest, especially in class 1, where dmfs + DMFS was 6.5 and 2.4, respectively. Form 1 students with literate parents had a higher caries mean, and class 1 pupils with defective school uniforms a lower mean. The apparently high‐risk groups did not consume more sweet snacks or clean their teeth less frequently. There was clearly more caries among the quartiles of children with most visible plaque on molars, but all social and demographic subgroups had similar amounts of plaque. Multivariate analyses of class 1 children showed that pupils living in urban areas, Fulas and Madingos, and children wearing complete school uniforms had caries significantly more frequently, other factors being equal. In form 1, urban students, rural Fulas and Madingos, students with literate parents, and urban students consuming sweet snacks frequently had significantly more caries. Social criteria were sufficient to identify rural children with high caries experience, but insufficient in urban areas.
Experiments with a toothpaste containing polydimethylsiloxan/triclosan
Authors: Rölla Gunnar , Gaare Dagrun , Ellingsen Jan Eirik
Published: October 2007

Polydimethylsiloxan (silicone oil) adsorbs to solid surfaces and to teeth because of its low surface tension, forming a thin, resistant layer. Triclosan is a lipidsoluble, antibacterial substance which is added to toothpastes and mouthwashes to inhibit plaque. Triclosan can be dissolved in silicone oil, conferring an antibacterial property on the layer of silicone oil which forms on solid surfaces. The aim of the present study was to determine whether a toothpaste containing triclosan/silicone oil has any effect on established gingivitis in a test panel of 33 teenagers. This toothpaste and a placebo paste were randomly distributed to the panel, and the number of gingival bleeding points was recorded. No instruction in oral hygiene was given. The panel was then examined 4 wk later and the number of bleeding points again recorded. It was found that the reduction in bleeding points was significantly higher in the group which had used the triclosan/silicone oil paste than in the placebo group. Deposition of a lipid‐soluble, antibacterial agent in a layer of silicone oil which adsorbs to the tooth surfaces because of its physical properties represents a new and promising principle in preventive dentistry.
An in vitro study of salivary film formation at solid/liquid interfaces
Authors: Vassilakos Nikolaos , Arnebrant Thomas , Glantz Per‐Olof
Published: October 2007

The aim of this study was to use the technique of in situ null ellipsometry to study some aspects of salivary film formation at solid/liquid interfaces. Experiments were performed in a fused quartz cell, and hydrophilic plasma cleaned silica and methylated hydrophobic silica surfaces were used as substrates. Samples of unstimulated whole saliva were allowed to adsorb on the test surfaces for 30 min. After the adsorption period, rinsing was performed for 5 min. Recordings were continued for another 30 min, and then new saliva samples were added in the cell. The results showed that statistically significant higher amounts were adsorbed on the hydrophobic than on the hydrophilic surfaces. The adsorbed films on both types of tested substrates consisted of loosely associated parts which were removed after rinsing and of more tightly adsorbed fractions. A significantly larger fraction was desorbed from the films adsorbed on the hydrophobic than on the hydrophilic surfaces. When saliva was introduced again in the cell, it was shown that the amounts adsorbed attained the values obtained before the rinsings. Increase in the concentration of saliva in the cell without previous rinsing did not cause any further increase in the mass of the adsorbed film.
Increased rate of salivary epidermal growth factor secretion in patients with juvenile periodontitis
Authors: Hormia Marketta , Thesleff Irma , Perheentupa Jaakko , Pesonen Kristiina , Saxén Leena
Published: October 2007

We compared salivary epidermal growth factor (EGF) concentrations in patients with juvenile periodontitis (JP) and periodontally healthy controls. In initial screening of 45 JP patients and a group of healthy controls, significantly higher salivary EGF concentrations were measured in the JP patients. Subsequently, 17 JP patients who had high EGF concentrations in some of their salivary samples were chosen, and a group of age‐ and sex‐matched controls was selected. We then examined their EGF concentrations and EGF secretion rates under standardized conditions in stimulated and unstimulated saliva and studied the expression of EGF receptor (EGF‐R) in their gingival tissues. The results showed that the mean EGF concentration (pmol/ml) was slightly higher in JP patients than in controls. However, the difference was statistically significant only in stimulated saliva and when calculated per milligram salivary protein. When EGF release was measured as the rate of EGF secretion (pg/min), significantly higher values were observed in JP patients than in controls both in unstimulated and stimulated saliva. Immunofluorescence microscopy (IF) of gingival samples from JP patients and their controls revealed no quantitative or qualitative differences in the expression of EGF‐R. Our results demonstrate the complex nature of salivary EGF release. The elevated rate of salivary EGF secretion in JP patients may be associated with the pathogenetic mechanisms of juvenile periodontitis.
Collagen I carboxyterminal propeptide in human gingival crevicular fluid before and after periodontal treatment
Authors: Talonpoika J. T. , Hämäläinen M. M.
Published: October 2007

The amount of procollagen I carboxyterminal propeptide (PICP) in crevicular fluid (CF) was measured in three periodontitis patients. Samples were collected from 29 sites before treatment (scaling, root planing, and curettage) and 2, 5, 10, 20, and 40 days after treatment, by placing two paper strips in periodontal pockets for 5 s. The amount of fluid in strips was measured by the Periotron device. Control samples were collected from subjects with minimal gingival inflammation. PICP was extracted into saline solution and determined by a radioimmunologic method. Plaque index, papilla bleeding index, and pocket depth were recorded before and 40 days after treatment. The CF PICP mean concentration was 4.2 mg/1 in the pretreatment samples. Five days after treatment a statistically significant increase in PICP concentration was seen in all subjects. The peak appeared on days 5 or 10 in 27 sites. The mean peak PICP concentrations of the subjects were 5‐10 times higher than the pretreatment values. Twenty days after treatment, mean PICP concentration decreased to pretreatment level. PICP concentrations did not correlate with the clinical parameters. In control samples PICP amounts were below the detection limit. CF PICP is a new marker of type 1 collagen metabolism in periodontal tissues. It was concluded that elevated PICP concentrations in CF after periodontal treatment reflected increased type I collagen synthesis in periodontal tissues and that the peak in type I collagen synthesis takes place 5‐10 days after treatment.
Variables related to masseter muscle function: a maximum R2 improvement analysis
Authors: Bakke Merete , Stoltze Kaj , Tuxen Anette
Published: October 2007

A multiple linear regression analysis, with stepwise maximum R2 improvement technique by forward selection and pair switching, was used to select the occlusal, morphologic, and histologic variables which explained most of the variation in bite force and electric masseter muscle activity. The variables comprised tooth contact and facial morphology together with thickness and fiber characteristics of the masseter muscle. The study included 13 healthy women, 21–28 yr of age, with a minimum of 24 teeth and no serious malocclusion. Significant exploratory models (R2: 0.55–0.85) were shown concerning bite force, and electromyographic amplitude during resting posture, maximal voluntary contraction (ICP), and unilateral chewing, as well as contraction time (chewing side). Muscle thickness and molar contact had a significant, positive effect on the level of forceful muscle contraction. The explorative model both demonstrated explicable relations, and offered better insight into interrelations than did univariate analysis.
Trabecular bone mineral density of mandible and alveolar height in postmenopausal women
Authors: Klemetti Esa , Vainio Pauli , Lassila Veijo , Alhava Esko
Published: October 2007

Mineral density of the trabecular bone of the mandible was determined by single‐energy QCT (quantitative computed tomography) for 74 totally or nearly edentulous menopausal women. These results were compared with the bone mineral densities (BMD) of their lumbar area (L2–L4) and femoral collum, measured by dual‐energy x‐ray transmission, Lunar DPX. The remaining height of the residual ridge at the symphysis of the mandible was measured on computed tomography (CT) lateral projection view, and an index of the residual ridge status was introduced. To determine whether general osteoporosis status affects the remaining height of the residual ridges, we compared these values with all results for bone mineral density. The BMD of the lumbar area and that of the femoral collum correlated well with each other, but the BMD of the trabecular bone of the mandible did not correlate with either of the other two BMD measurements. Measurements of residual ridge height did not correlate with any BMD values. The effect of possible bone loss earlier in life is no longer apparent in mandibular height or trabecular BMD over 20 yr after tooth extractions.
Longitudinal relationship between incisal tooth wear and periodontal condition
Authors: Silness John , Johannessen Gerd , Röynstrand Torgeir
Published: October 2007

The purpose of the study was to examine the relationship between the longitudinal development of incisal tooth wear and periodontal conditions in 51 persons. Stone casts obtained at the ages of 15 and 27 yr were used to assess incisal wear according to a graded scale, the Incisal wear Index (Iwl). The wear increase after 12 yr, ΔIwI, was related to the various health index scores at the age of 15 yr, including the Plaque Index (PII) and Gingival Index (GI) systems. The chi‐square tests showed a statistically significant association between AIwI and periodontal condition in 15‐yr‐olds. Thus, relatively low P1I and GI values were accompanied by relatively high AIwI values. It was concluded that in 15‐yr‐olds, P1I and GI levels are clinical predictors of future wear (ΔIwI) of maxillary and mandibular central incisors. Pocket depth (PD) was a less valuable clinical predictor of such wear.