bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinical effects of glazing denture acrylic resin bases using an ultraviolet curing method
Authors: BUDTZ‐JÖRGENSEN EJVIND , KAABER SVEND
Published: October 2007

Abstract – Control of denture plaque accumulation is essential to obtain and maintain a healthy oral mucosa in denture wearers. The present study was designed to study the effect on denture plaque accumulation and denture stomatitis of coating the fitting denture surface by a glaze. Twenty‐one subjects wearing complete dentures participated in the study. Glazing of the denture surface was performed using a Perma Cure System. Plaque accumulation was studied clinically and using a semiquantitative microbiologic technique. Plaque accumulation on the glazed and the non‐glazed halves of the fitting denture surface was compared after 1 wk. There was significantly less plaque on the glazed half of the denture (P<0.001), and the calculated number of CFU of bacteria/cm2 was significantly lower from the test area of the glazed half than from the test area, of the non‐glazed half of the denture (P<0.001). When the patients were reexamined 1 month after the entire fitting denture surface bad been glazed plaque scores, yeast scores and number of CFU of bacteria/cm2 were not significantly different from those observed before glazing. There was a reduction of the erythema of the palatal mucosa in 14/19 patients with denture‐induced stomatitis. The study indicates that coating of the fitting denture surface by a glaze may be a means to improve denture cleanliness; however, the present glazing system should be further developed to produce a more uniform glazing.
Erupting third molars and salivary lactobacilli and Streptococcus mutans counts
Authors: MEURMAN JUKKA H. , RYTÖMAA INKERI , MURTOMAA HEIKKI , TURTOLA LAURI
Published: October 2007

Abstract — The salivary lactobacilli and Streptococcus mutans county in 217 university students of 25.4‐yr‐old were studied with regard to the state of eruption of their third molar teeth. Statistically significantly higher counts of both bacterial species were found in students who had one or more third molars partly erupted, compared with those whose third molars were lacking or fully erupted. No other parameters studied such as salivary flow rate or buffering capacity of the saliva were found to explain the high bacteria1 counts. These findings should be taken into consideration when interpreting salivary microbial counts in young adults. Also, special interest should be focused into these aspects at oral hygiene and dietary counseling of young patients.
In vitro studies of monocyte function in two siblings with Papillon‐Lefèvre syndrome
Authors: PREUS HANS R. , MÖRLAND BERIT
Published: October 2007

Abstract — Blood monocytes were isolated from two siblings with Papillon‐Leferve syndrome (PLs) and compared to corresponding cells from their healthy cousin. The number ofmonocytes isolated were within normal limits in all three test participants. Aggregating tendency was increased when PLs monocytes were cuitured in ihe presence of autologous sera. The monocyre ability or specific immune phagocytosis was decreased in PLs patients. The mnonocyte marphology, non‐specilic phagocytosis, lysosomal enzyme activities, and response to E. coli endo‐toxin were similar in patients and control.
Influence of projection angles upon position of cementoenamel junction on radiographs
Authors: SEWERIN IB , ANDERSEN VIBEKE , STOLTZE KAJ
Published: October 2007

Abstract — The CEJ on radiographs is often used as a reference point in the assessment of alveolar bone loss. The aim of the present study was to test the stability of the radiographic CEJ (“RCEJ”) in relation to the alveolar west under varying angulations of the central X‐ray beam. In an experimental model four types of extracted teeth were radicrgraphed al 0° and 20° vertical angulation and at 15 horizontal angulations varying from a 17.5° mesial view to a 17.5° distal view. The buccal alveolar bone margin was simulated by a steel needle. RCEJ‐“crest” distances were read at a × 10 magnification. Changing the vertical angutation from 0° to 20° reduced the RCEJ‐“crest” distances far all tooth types (range ofaverage reduction 2.2–4.1 mm). HorizontaE angulations without concomitant vertical angularion had a significant effect but where without clinical significance. Horizontal anglslations in combination with a 20° vertical angulation bad a considerable influence; in a mesial view, mesial RCEJ‐“crest” distances decreas‐ed and distal ones increased, and vice wna in a distal view. The deviations from the true CEJ‐crest distance demonstrated may be of clinical significance, and a critical attitude to alveolar bone loss measures on radiographs using the RCEJ as reference point is recommended.
Identification of cellulose fibers in oral biopsies
Authors: KOPPANG HANNA STRÖMME , KOPPANG ROLF , SOLLHEIM TORE , AARNES HALVOR , STÖLEN STEINAR ÖRBECK
Published: October 2007

Abstract – Oral biopsies comprising five periapical cysts, three cases of exuberant granulation tissue in extraction sockets and one case of a mandibular radiopaque structure, all displaying material consistent with cellulose fibers on routine histologic examination, were subjected to histochemical, polarization, fluorescence and scanning electron microscopical, energy dispersive X‐ray and chemical investigations. Routine screening of periapical lesions with polarization microscopy and identification of possible cellulose fibers with Calcofluor White is advocated. Further, attention is drawn to endodontic paper point material as an etiologic factor in postendo‐dontic periapical inflammatory processes.
β‐N‐acetyl‐D‐glucosarninidase (NAGase) and lysozyme activity in human parotid and submandibular saliva
Authors: FOUDA NASSER EL‐TOUKHY , SÖDER PER‐ÖSTEN , SVENSSON MARIE‐LOUISE
Published: October 2007

Abstract – β‐N‐acetyl‐D‐glucosaminidase (NAGase) and lysozyme activity were studied in isolated parotid and submandibular saliva collected from five healthy individuals over a 3‐wk period. During the first week, saliva samples were collected three times within one specified day (9 a.m., noon, 4 p.m.). Then for each of the following 2 wk, saliva was collected at 9 a.m. of the same day. NAGase activity was determined spectrophotometrically by using p‐nitrophenyl‐glycoside as substrate. Lysozyme activity was determined turbidimetrically by using Micrococcus lysodeikticus cells as substrate. NAGase and lysozyme were present in all samples of parotid and submandibular saliva. NAGase activity was generally higher in saliva samples collected in the morning and decreased during the day. There was considerable variation in NAGase activity and almost no variation in lysozyme activity in samples taken from the same person. NAGase activity was higher in parotid than in submandibular saliva while lysozyme activity was somewhat higher in submandibular saliva.
Review of the literature and a recommended system of malignancy grading in oral squamous cell carcinomas
Authors: ANNEROTH GÖRAN , BATSAKIS JOHN , LUNA MARIO
Published: October 2007

Abstract – A review of histologic classification systems for grading of malignancy in squamous cell carcinomas of the head and neck region is presented. Reasons behind the varying results obtained in studies using his tomorphologic grading schemes are presented and potential errors involved in this type of clinical research are discussed. Requirements for the study of correlations between malignancy grade scoring, and recurrence and survival rates are presented. These include factors as patient selection, clinical staging, and follow‐up principles. Special attention must be given to treatment modalities, establishment of negative surgical margins and occurrence of regional lymph node and/or distant metastases.
Recurrent herpes labialis in a military brass band
Authors: BARKVOLL PAL , ATTRAMADAL AUDUN
Published: October 2007

Abstract – 80–90% of the adult population is known to have neutralizing antibodies to herpes simplex virus type 1 (HSV1), of these 18–32%suffer from occasional recurrent herpes labialis (RHL). It is thought that local trigger factors as external traumata, UV‐light and chemical stimuli, or systemic factors like fever or common cold, may induce RHL. The aim of the present study was to investigate lie frequency of RHL in a military brass band and compare this with the frequency of the disease in a control population of soldiers from the same unit. Both populations were national servicemen aged 19–22 yr. The diagnosis of RHL was based on the presence of herpetic vesicles in the labial region. Of the diagnosed cases, 10% were confirmed by laboratory procedures according to standard methods. The incidence of RHL over a period of 8 months was twice as frequent in the group of brass, and woodwind players as in the control group of soldiers from the same military unit. This may indicate that the mechanical trauma to the labial tissue which occurs during playing may cause the increased frequency of RHL in musicians.
Histometric study of root resorption on human premolars following experimental replantation
Authors: BREIVIK MARTIN , KVAM EINAR
Published: October 2007

Abstract – A histometric method was applied for evaluation of root resorption in 57 experimentally replanted teeth and 22 controls. Representative axiobuccolingual sections were selected for measurement of resorptions at a magnification of × 40. The frequency of root resorption in the control teeth was low. In replanted teeth marked resorptive activity elicited by the trauma appeared after 2 wk. The extent of active resorptions increased until the third postoperative week. On an average 14% of the root periphery was affected at this stage. After the sixth postoperative week progressive cement deposition took place in the resorption lacunae. Incidental ankylosis of the periodontal membrane also occurred from this observation time but there was no increase among the long‐term groups.
Scanning electron microscopy of early microbial colonization of human enamel and root surfaces in vivo
Authors: NYVAD BENTE , FEJERSKOV OLE
Published: October 2007

Abstract – This study describes the pattern of microbial colonization in six dental students, who carried test pieces of enamel and root surface in intraoral acrylic appliances for 4, 8, 12, 24, and 48 h, respectively. Oral hygiene was discontinued during the experimental periods. The results showed that oral microorganisms colonized enamel and root surfaces individually. The pattern of colonization mimicked the surface structure of the tooth; on enamel surfaces the first bacteria appeared in pits and surface irregularities followed by proliferation along the perikymata, while on root surfaces bacterial colonization was characterized by a haphazard distribution. Within the initial 24‐h period root surfaces were more heavily colonized than were enamel surfaces. This pattern was characteristic irrespective of differences in the intra‐ and interindividual rates of bacterial coverage. It is concluded that early microbial colonization in vivo is determined by the surface structure of the tooth. Consequently, natural tooth surfaces should not be replaced by artificial surfaces in structural studies of microbial deposits in the oral cavity.
Cytotoxic effects of cobalt‐chromium alloys on fibroblasts derived from human gingiva
Authors: ARVIDSON KRISTINA , COTTLER‐FOX MICHELE , HAMMARLUND ERNA , FRIBERG ULF
Published: October 2007

Abstract – The in vitro toxicity of 15 different cobalt‐chromium alloys used in removable partial dentures and dental implants was studied. The composition of the alloys was determined by X‐ray spectrometry. Alloys were tested on human oral fibroblasts in low density, semiconfluent or confluent cultures. The cultures were observed in a phase contrast microscope over a period of 3 wk. The alloys could be divided into three groups depending upon the degree of cell injury evoked. Group I alloys caused no cell injury. Group II alloys caused slight to moderate cell injury seen first after 3–7 days of exposure. Group III alloys caused severe cell injury with signs of cell damage detected after 12 h and total ceil death after 3–14 days. The alloys' composition varied considerably with regard to cobalt, chromium and nickel as well as other components. Nevertheless, group II and III alloys had a higher nickel content than group I alloys in general.
Effects of chlorhexidine, NaF and SnF2 on glucan formation by salivary and culture supernatant GTF adsorbed to hydroxyapatite
Authors: SCHEIE ANNE AA. , KJEILEN JANICKE C. J.
Published: October 2007

Abstract – Chlorhexidine, NaF and SnF2 were tested for inhibitory activity against glucosyltrans‐ferase (GTF) which had been adsorbed to hydroxyapatite. The sources of GTF were culture supernatants of S. mutans grown in BHI or stimulated whole saliva supernatants. Chlorhexidine inhibited GTF activity from culture supernatants as well as from saliva. NaF and SnF2 had moderate effects.
Prevalence of mutans streptococci and lactobacilli in elderly Swedish individuals
Authors: EMILSON CLAES‐GÖRAN , THORSELIUS INGER
Published: October 2007

Abstract — The number of Streptococcus mutans, Streptococcus sobrinus, and lactobacilli in stimulated whole saliva was examined in 149 elderly persons. More than 106 CFU/ml of mutans streptococci were found in 57% of the subjects and 85% had more than 105 lactobacilli per ml of saliva. There was no difference in the prevalence of mutans streptococci between edentulous and dentate subjects whereas significantly more lactobacilli were detected in denture wearers, S. mutans was most frequent and was found in 72% of the subjects. S. sobrinus, which was carried by 44% of the persons, was found proportionally in more subjects with dentures than in dentate individuals. In most persons with S. sobrinus, S. mutans was also present but in 8% of the subjects only S. sobrinus was detected. The subjects with both S. mutans and S. sobrinus had higher salivary levels of mutans streptococci than individuals with only S. mutans or S. sobrinus.
Interaction between chlorhexidine digluconate and sodium monofluorophosphate in vitro
Authors: BARKVOLL PAL , RÖLLA GUNNAR , BELLAGAMBA SANDRA
Published: October 2007

Abstract — The aim of the present study was to investigate the compatibility of chlorhexidine digluconate and sodium monofluorophosphate since these agents are potential ingredients in future products in preventive dentistry. Varying combinations of chlorhexidine digluconate and sodium monofluorophosphate in water, covering the possible ranges of clinically relevant concentrations of both compounds, were made, incubated for 24 h and observed for precipitation of insoluble salts. The mixtures were analyzed for presence of free chlorhexidine and monofluorophosphate after incubation. The results showed that chlorhexidine digluconate and sodium monofluorophosphate are not compatible in clinically relevant concentrations. A chlorhexidine‐ monofluorophosphate salt of low solubility in water is presumably formed.
Immunogenic potential of some mercury compounds in experimental contact allergy of the rat oral mucosa
Authors: KINNBY BERTIL , KÖNSBERG RICHARD , LARSSON AKE
Published: October 2007

Abstract — The contact allergenic potential of substances included in a “dental screening test” has been investigated in a previously established animal model for producing contact allergy. We were unable to produce contact hypersensitivity with any of the original formulas. HgCl2 was selected for further studies and, in order to improve its penetration, butanol was used as a solvent. Sensitization was, however, not obtained with any of the HgCl2/butanol formulas. Our results are discussed in relation to the requirements of reaching immunogenic threshold levels of mercury in the tissue.
Antibody to human papilloma virus in Danish dentists
Authors: GENNER JÖRGEN , SCHEUTZ FLEMMING , EBBESEN PETER , MELBYE MADS
Published: October 2007

Abstract — The aim of this study was to investigate the seroprevalence of antibody to human papilloma virus (HPV) among Danish dentists in order to determine whether this virus constitutes an occupational hazard for dentists. Serum samples from 452 Danish dentists were tested for antibody against a common capsid antigen to HPV by a complement fixation reaction. Nine (2.0%) were seropositive. Dentists'odds ratio for seropositivity was after adjustment for age 0.6 (90% confidence interval: 0.3–1.4) compared to that of voluntary blood donors. In conclusion, Danish dentists do not seem to be at an increased risk of becoming infected with HPV.
Ranking of histologic tissue responses in the biologic evaluation of dental materials
Authors: KALLUS T. , GJERDET N. R. , SYRJÄNEN S. , MJÖR I. A.
Published: October 2007

Abstract – Implantation tests are frequently used to evaluate biological properties of dental materials. The tissue reactions have been rated as no, slight, moderate and severe responses, mainly based on a quantitative assessment of the cellular response. The distinction between categories is subject to discussion, and interexaminer calibration is necessary to obtain reproducible results. This paper presents a statistical method of evaluating tissue reaction by ranking photographic prints representing histologic sections. Polyethylene tubes, carrying the materials, were implanted subcutaneously in guinea pigs. The tissue reactions at the tube ends, where the material was exposed to the tissue, were evaluated. Photographs of 20 histologic sections were selected. Five investigators from a scientific staff and five from a group of assisting personnel with minimal instruction ranked the reactions on the prints in increasing order of severity. Assisting personnel received 1 h of instruction before the ranking. Generally, the rank ordering of the different examiners showed good agreement. Qualitative histopathologic examination of the sections indicated a marked variation in the cellular response, which limits, the value of the quantitative assessment.
Spreading of dentinoclasts on various substrata in vitro
Authors: LINDSKOG SVEN , PIERCE ANGELA
Published: October 2007

Abstract – An in vitro system for isolated dentinoclasts is described in which clastic cells which are not contemporaneously engaged in resorption are gently rinsed from the surface of actively resorbing root dentin. Dentinoclasts were cultured on a variety of hard tissue constituents in order to investigate the effects of substratum composition on the expression of resorbing structures by these cells, and examined with scanning electron microscopy. Results revealed that dentinoclasts express both ruffled borders and clear zones only when cultured on coverslips coated with both collagen and hydroxyapatite. Hydroxyapatite alone induced only the formation of a clear zone. Failure to express either clear zones or ruffled borders by cells cultured on collagen‐coated coverslips was interpreted to reveal that collagen itself is not capable of, but requires the mineral component of hard tissue for, producing morphologic resorbing structures in clastic cells.
Crystalline inclusions in epithelial cells of hairy leukoplakia: a new ultrastructural finding
Authors: EL‐LABBAN N. , RINDUM J. , NIELSEN H. , PINDBORG J. J.
Published: October 2007

Abstract – Hairy leukoplakia is often the first manifestation of an HIV infection. In the present study we have investigated the ultrastractural features of hairy leukoplakia in two HIV seropositive male homosexual patients. Ultrastructurally EBV particles were found in the upper prickle and keratinized epithelial cells, whereas papilloma virus particles were not found. Candida albicans were also seen in the keratinized layer. In addition two types of inclusions which have not previously been reported in hairy leukoplakia were commonly seen in the epithelial cells containing the EBV. The first was a crystalline microtubular structure which may take the form of several arrays. The second was an elongated multivesicular structure consisting of membrane‐bound rounded vesicles embedded in a background of fine filaments. The vesicles were similar to the empty looking EBV particles and their mean diameter was 100 nm. Further investigations are needed to elucidate the exact nature of these structures and their relationship to the Epstein‐Barr virus.
Secretion of glucose in human parotid saliva after carbohydrate intake
Authors: BORG ANNIKA , BIRKHED DOWEN
Published: October 2007

Abstract – The aims of the present investigation were, first, to follow the secretion of free glucose in parotid saliva in various subjects after a single oral intake of different carbohydrates, and second, to compare the salivary glucose concentration with the concentration in blood. Twenty healthy subjects, three women and 17 men, 20–35 yr of age, participated. They were asked not to eat or drink anything from 10 p.m. the night before the examination. 75 g of carbohydrate (glucose, fructose, or sucrose) dissolved in 300 ml water was ingested the next morning at 8 a.m. One experimental series with glucose was performed in triplicate in 10 of the subjects. Approximately 1.5 ml of citric acid‐stimulated parotid saliva was collected before (0 min) and 15, 30, 45, 60, and 120 min after the intake. Salivary concentration of glucose was analyzed enzymatically. Most of the 0‐min samples showed a variation in glucose concentration from 5 to 25 μmol/l. After the glucose, fructose, and sucrose intakes, the salivary glucose level increased about 2–4 times, especially in the 30‐min samples. A large inter‐ as well as intra‐individual variation was found both in the 0‐min samples and in the samples collected after the different intakes. The correlation between the glucose concentration in saliva and blood was higher after than before the carbohydrate intakes.
Collagen deposition during wound repair in rat gingiva
Authors: GREVSTAD HANS JACOB
Published: October 2007

Abstract – The aim of this study was to examine day‐by‐day changes at incisional wound edge in rat molar interdental tissue with special reference to early interactions of new and pre‐existing collagen fibrils. Twenty rats aged 50 days were divided into experimental groups each comprising two animals. Following incision and post‐injury observation periods of 1–10 days, the rats were given an overdose of sodium pentothal and specimens prepared for light and electron microscopy. In 1‐3‐day post‐injury specimens fibrin was replaced by inflammatory cells. Fibroblasts were found along the cut edge in 4‐day post‐injury specimens. Fibrillogenesis had started at 5 days post‐injury. During the period of 5–10 days post‐injury increasing amounts of new collagen fibrils were laid down at the wound edge. No granular material was identified at the interface of new and preexisting collagen. In standardized mesiodistal sections, bundles of newly formed fibrils regularly appeared cross‐cut in relation to the tangentially cut transseptal fiber system, suggestive of a buccolingual fibril orientation at the wound edge. The ultrastructural observations indicate that during early stages of wound repair, connective tissue continuity is generally established without direct splicing of severed fibers.
Effect of load‐cycling on bond between composite fillings and dentin established by Gluma and various resins
Authors: MUNKSGAARD ERIK CHRISTIAN , IRIE MASAO
Published: October 2007

Abstract – Cylindrical dentin cavities, pretreated with Gluma and various resins, were filled with Silux, P‐30, or Concise. Marginal integrity was in most instances obtained when experimental resins containing propionic aldehyde were used. The bond between composite and dentin established in this way was tested by load‐cycling. Cervical located cavities in extracted human teeth, approximately one‐half of the margins in dentin, were etched and treated as above. Fillings made of Silux, P‐30, or Concise exhibited margins without stain upon axial loading in most cases. The frequency of staining increased when Dycal was used as cavity liner, but were absent in all cases when Concise was used as filling material. The content of propionic aldehyde in the intermediary resin layer may reduce the oxygen tension at the interface and thereby increase the rate of the polymerization at this location.
Effect of moderate protein‐deficiency on ultrastructure in parotid and submandibular acinar cells in the adult rat
Authors: JOHANSSON INGEGERD , ALM PER
Published: October 2007

Abstract—Powdered diets, of three different levels of protein, were given to groups of adult male rats for 21 days. Two diets with reduced protein content, 5% or 10% casein, were given to experimental rats. A diet with an adequate protein content, 20% casein, was given to controls. A reference group of rats was fed a standard pellet diet for the same period. At the end of the experimental period, the parotid and the submandibular glands were removed and subjected to electron microscopy. The zymogen granules of acinar cells in the parotid glands from the rats receiving the 5% protein diet had lost their normal opaqueness and turned electron lucid whereas parotid glands from the rats fed the 20%, the 10%, and the standard pellet diet exhibited normal acinar cells. The ultrastructure of submandibular acinar cells was not affected in any dietary group.
Clinical significance of isometric bite force versus electrical activity in temporal and masseter muscles
Authors: BAKKE MERETE , MICHLER LARS , HAN KE , MÖLLER EIGILD
Published: October 2007

Abstract— Bite force and activity in temporal and masseter muscles during biting and chewing were recorded in 19 control subjects and 23 subjects with symptoms and signs of functional disorders of the craniomandibular system. The entire group comprised 13 men and 29 women, 14–63 yr of age. Maximal unilateral bite force was 480 Newton (N) in control subjects and 387 N in patients, with corresponding bilateral values of 347 N and 230 N. At predetermined levels of contraction, temporalis and masseter activity were linearly related. Correlations of bite force and activity in short static contractions were significant with respect to unilateral, but not to bilateral force measurements. Only in the masseter muscle was strength of dynamic contractions during chewing significantly correlated to bite force. With the present method it was demonstrated that unilateral bite force is a simple clinical indicator of mandibular elevator strength as a whole, but inadequate to disclose asymmetric conditions. During isometric contraction, relative strength of electromyographic activity fairly accurately imaged the output of mechanical activity.
A cross‐sectional study of DMFT and CPITN scores in a group of Indonesian soldiers
Authors: GAARE DAGRUN , JOELIMAR FELIX ARYADI , OUDERAA FRANZ V. D. , RÖLLA GUNNAR
Published: October 2007

Abstract – A cross‐sectional clinical study showed that the prevalence of caries among Indonesian soldiers was low, compared with that found in corresponding Western populations. Also, the progression of caries was very slow, and caries was limited almost exclusively to the occlusal surfaces of the teeth. Among officers, the prevalence of caries was lower than it was among other ranks of the same age. The low general prevalence of caries among Indonesian soldiers may be related to diet. Rice was the major source of carbohydrate for the soldiers, and their sucrose consumption was 10 kg per person per year. Their drinking water contained a low concentration of fluoride (0.1 ppm). In spite of massive accumulations of calculus, the periodontal health of young soldiers (< 26 yr) was also good. Among those in higher age groups, however, periodontal health had deteriorated, but even in a group aged 40–46 yr, no teeth had been lost as a result of periodontal disease. Among officers, periodontal health was better than it was amongst other ranks of corresponding age. The officers had been accustomed to brushing their teeth regularly, whereas the other ranks had not. It thus appears that toothbrushing may help to preserve periodontal health, even when large amounts of calculus are present on the teeth and there is no opportunity for it to be removed regularly by a dentist.
Why is sucrose so cariogenic? The role of glucosyltransferase and polysaccharides
Authors: RÖLLA GUNNAR
Published: October 2007

Abstract – Some aspects of the cariogenicity of sucrose are discussed, in particular the data indicating that glucosyltransferase (GTF) mediates the well known stickiness of sucrose exposed S. mutans and plaque in vivo. The non‐sucrose dependent colonization of teeth, which has been studied extensively, is judged to be of less importance because S. mutans is only pathogenic in combination with sucrose. Strong evidence from several laboratories show that free GTF is present in saliva and that it adsorbs to the pellicle and is able to form glucan in the adsorbed state. Glucan‐glucan interaction between 1–3 linked glucans gives a strong sucrose dependent interaction between glucan chains originating from the GTF adsorbed to the pellicle and from GTF on the bacterial surface.
Impact of streptozotocin‐induced diabetes on rat blood and alveolar bone affected by occlusal stress
Authors: LASSILA VEIJO , VIRTANEN PAULI
Published: October 2007

Abstract – Adult male and female rats were used as test animals. The experimental diabetes, mellitus was provoked with one dose of i.v. injection of streptozotocin (65 mg/kg body weight), which interferes with the insulin release mechanism in pancreatic β cells. After a follow‐up period of 10 wk an average loss of 10% of body weight and an increase of 25% in the amount of blood obtained by decapitation was recorded in the test animals. The biochemical assays performed on the serum of the diabetic rats showed, for both sexes, a fourfold rise in the plasma glucose level, a threefold rise in plasma alkaline phosphatase activity and plasma alanine transferase activity as well as a 1.5‐fold rise in plasma creatine value. The two latter values indicated systematic disorders reflected in the liver and the kidneys. An increase in serum total calcium and hydroxyproline values was also detected. The clinical studies of the gingiva showed diminished tissue resistance in diabetic rats. The histologic studies of alveolar bone revealed retarded formation of bone matrix and new bone in diabetic animals. However, the stimulated metabolism in alveolar bone, due to the artificially induced stress, increased marginal bone cell activity in both the diabetic and the control group, resulting in increased crestal resorption in the former group. The differences in tissue response observed among the diabetic animals affected and unaffected by stress originated from the disturbed recovering mechanism typically found in diabetic animals.
One‐year study of the efficacy of a dentifrice containing zinc citrate and triclosan to maintain gingival health
Authors: SVATUN BJARNE , SAXTON CHARLES A. , RÖLLA GUNNAR , VAN DER OUDERAA FRANS
Published: October 2007

Abstract – In a previous study we demonstrated that gingival health could be maintained in a group of highly motivated nurses using a dentifrice containing a zinc salt and triclosan. We have now investigated the effect of the experimental dentifrice on a group of less motivated men. One hundred and three male students were given oral hygiene instruction (OHI) and their teeth were professionally cleaned. For each individual, both the instruction and cleaning were completed in a single 15‐min period. Two balanced groups were formed, based on the prestudy plaque levels and gingival bleeding. One group used the experimental dentifrice for 12 months, while the other used a control. Results were assessed after 6 months, and after 12 months. As a result of the OHI, plaque and gingival bleeding were reduced at the end of the prestudy period. This improvement was not maintained by the control group even for 6 months. In contrast, the test group exhibited significantly lower plaque levels and higher standard of gingival health throughout the 12 months. Reassessment of available participants 6 months after the study showed that gingival health in both groups had returned to its prestudy condition. The lower observed standard of gingival health in the test group after ceasing to use the experimental dentifrice further supports the conclusion that this dentifrice can contribute to an oral care program.
Effect of critical surface tension on retention of oral microorganisms
Authors: CHRISTERSSON CECILIA E. , DUNFORD ROBERT G. , GLANTZ PER‐OLOF J. , BAIER ROBERT E.
Published: October 2007

Abstract – The effect of critical surface tension on the initial retention of microorganisms from unstimulated human saliva was tested in a flow cell system. Prior to each experiment the total numbers and the morphotypes of microorganisms present in saliva were recorded. The test surfaces were prepared to display known increasing critical surface tensions, as verified and standardized by contact angle measurements. Surfaces of initially low (20–22 mN/m), medium (35–38 mN/m) and high (>50 mN/m) critical surface tension were exposed to saliva at a flow rate of 1 ml/min. Microbiota and biofilm material associated with the test surface after 15 min of salivary exposure, were then subjected to standard detachment forces, by introducing a cell‐free rinsing fluid at two different shear rates. Both the attachment and the detachment phases were executed at room temperature or 37°C. The retained population was counted in three different zones of the test surfaces with a light microscope and statistically tested for correlation to the main variables (critical surface tension, flow rate and temperature) and interactions. Retention success was significantly dependent on the initial critical surface tension and the flow rate. Surfaces of medium critical surface tension, representative of human tooth surfaces and most restorative dental materials, retained the highest numbers of microorganisms in comparison with the other surfaces tested, with no statistically verified selectivity in proportions of retained coccoid and rodshaped microorganisms for any surface. A 30‐fold increase of the flow rate resulted in a 70–80% reduction of the retention success, with a higher relative number of cocci present on all the test surfaces. These results demonstrate that initial retention of microorganisms to surfaces is non‐specific with regard to morphotypes, but is strongly related both to the mechanical removal forces and the surface energetic state of the solid surface exposed. Retention of microbial populations at interfaces might, advance selection of the critical surface tensions and predicted if shear forces at given sites are known.
Influence of glutardialdehyde on dentin demineralization in vitro and in vivo
Authors: ARENDS JOOP , ÖGAARD BJÖRN , RUBEN JAN , WEMES JAAP , RÖLLA GUNNAR
Published: October 2007

Abstract – In this paper the results are presented on the action of glutardialdehyde (GDA) on the in vitro demineralization of human dentin and on the in vivo demineralization of dentin using the Ögaard orthodontic banding system. The results show that a 2 min application of a 2% GDA solution at pH = 3.6 reduces dentin demineralization in vitro and in vivo substantially. Microradiography shows a percentage reduction of lesion depth and mineral loss in vitro of 20 and 36%, respectively. After 2 wk in vivo demineralization the same percentage reductions are 60 and 44%, respectively. The mechanism of action of GDA on dentin is not certain yet. Presumably the in vitro action is due to surface cross‐linking of the dentin matrix causing reduced Ca and phosphate transport out of the dentin. In vivo an additional effect may be a rather short term influence of GDA on plaque or on plaque accumulation. The results of this paper indicate that glutardialdehyde is an interesting agent to consider in the reduction of root caries.
Accuracy of alginate and elastomeric impression materials
Authors: PEUTZFELDT ANNE , ASMUSSEN ERIK
Published: October 2007

Abstract – The accuracy of three alginates and seven elastomeric impression materials was determined. Impressions were taken of a truncated cone and poured with stone die. A steel ring fitting the steel cone was placed on the dies, and the discrepancy between the top surface of the ring and the die was measured. From these measurements the deviation between the base diameter of the die and that of the cone was calculated and used to express the accuracy of an impression material. All impressions showed a net shrinkage, resulting in too large a die stone and incomplete seating of the steel ring. The inaccuracy of the alginates varied between 44 and 188 μm. Blueprint regular was found to be significantly more accurate than the two other alginates investigated, and had a degree of accuracy comparable with that of the more accurate elastomeric impression materials. Within this group of materials the inaccuracy varied between 39 and 130 μm. Generally, the addition‐curing silicones were more accurate than the polyethers. Baysilex and President regular body had the highest degree of accuracy of the elastomeric impression materials.
Antibacterial activity of dental gels containing combinations of amine fluoride, stannous fluoride, and chlorhexidine against cariogenic bacteria
Authors: OSTELA ILKKA , TENOVUO JORMA
Published: October 2007

Abstract – The in vitro susceptibility of Streptococcus mutans, S. sobrinus and Lactobacillus casei to dental gels containing various combinations of amine fluoride (AmF 297), stannous fluoride (SnF2), and chlorhexidine (CHX) was studied. The combination of AmF‐SnF2 with a total fluoride content of 1.2% was the most effective against mutans streptococci but not against L. casei. At notably lower total fluoride concentration (0.4%), AmF as such or combined with SnF2, was significantly less effective against mutans streptococci than CHX or CHX‐AmF‐SnF2 combinations. CHX‐AmF combination was a slightly more potent inhibitor of streptococcal growth than CHX‐NaF. With L. casei the differences between various gels were small but CHX alone seemed to be the most effective. Of the studied agents, CHX seemed to be the most potent individual chemotherapeutic compound whose activity against S. mutans could be enhanced by combining it with AmF. However, clinical experiments are required to test the in vivo antibacterial efficacy of CHX‐AmF and AmF‐SnF2 combinations which were most effective in our in vitro experiments.
Microleakage in fissures sealed with resin or glass ionomer cement
Authors: ÖVREBÖ ROSANE COSTA , RAADAL MAGNE
Published: October 2007

Abstract – The purpose of this study was to investigate if microleakage occurs in fissures after being sealed with a glass ionomer cement (Fuji III). Ten pairs, of contralateral maxillary premolars, to be extracted for orthodontic reasons, were sealed in vivo. Glass ionomer cement was randomly used on one tooth and diluted composite on the contralateral. An air‐polishing instrument was used for cleaning the fissures before sealing them. After 14 days the sealant status was recorded clinically and the teeth were extracted. They were placed in a 0.5% solution of methyl blue, subjected to a thermal cycling procedure, and finally sectioned. The sections were photographed in a stereomicroscope, and two observers recorded the microleakage according to a scoring system. Three glass ionomer sealings were clinically recorded as missing, one partly missing, and six intact, while all the resin sealings were present. Extensive leakage was seen in all glass ionomer specimens with dye penetration throughout the material as well as at the interface between cement and enamel. No leakage was seen in the composite specimens. Remnants of glass ionomer cement were observed in most of the sections from teeth which clinically seemed to have lost the sealing. This study indicates that Fuji III is poorly retained in the fissures, and that the material permits leakage even when it is fully retained. The material may, however, prevent caries by release of fluorides, and the fact that remnants of cement were found in fissures which clinically seemed to have lost it, indicates that this may even occur in cases with loss of retention.
Effect of sodium lauryl sulfate on protein adsorption to hydroxyapatite in vitro and on pellicle formation in vivo
Authors: RYKKE MORTEN , RÖLLA GUNNAR , SÖNJU TORLEIF
Published: October 2007

Abstract – Sodium lauryl sulfate (SLS) is widely used as a synthetic detergent in dentifrices. It has been shown to have high affinity for hydroxyapatite (HA), and the binding mechanism has been proposed to be electrostatic, involving the negative sulfate terminals of the SLS and the calcium sites on the HA. The binding of SLS to HA may thus well interfere with the protein adsorption to HA. The aim of the present study was to examine the effect of SLS on protein adsorption in vitro and on pellicle formation in vivo. The effect on protein adsorption was studied using ion exchange chromatography. The effect on pellicle formation was studied using enamel fragments carried in the mouth. The study showed that SLS‐treated HA adsorbed less protein than untreated HA. Protein adsorbed to SLS‐treated HA was more firmly bound to HA as compared to untreated HA. SLS‐treated enamel fragments carried in the mouth showed a slower rate of pellicle formation than non‐treated enamel.
Short‐term and long‐term effects of chewing training on occlusal perception of thickness
Authors: KILIARIDIS STAVROS , TZAKIS MIHAIL G. , CARLSSON GUNNAR E.
Published: October 2007

Abstract – The aim of this study was to investigate the short‐term and long‐term effects of functional stimuli, induced by intense chewing and by prolonged systematic chewing training, on the response of occlusal perception of thickness. The material comprised 25 young adults divided into an experimental group (17) and a control group (8). The occlusal perception of thickness was tested by successively placing different thicknesses of aluminum foil between five pairs of occluding teeth, i.e. right and left second premolars and canines and one pair of the central incisors. The experimental group was tested 2 wk before the start of the experiment and at the start and the end of the experiment, i.e., after 4 wk systematic chewing training, and before and after 30 min intense chewing. The control group was tested on the same occasions but without performing any special chewing activity. The discrimination threshold increased in most of the subjects after 30 min of chewing, both before and after the 28‐day training period. This threshold increase was found in all groups of teeth tested. No changes were found in the discrimination threshold of the teeth tested after 28 days of chewing training. In the controls no differences were found between the recording occasions. Since no statistically significant differences were observed between the groups of teeth tested, the changes in the threshold of occlusal perception after intense chewing may reflect the influence of receptors other than periodontal, for example those in TMJ and muscles, which are involved in the control of other neuromuscular mechanisms such as those that control the postural position of the mandible.
Desorption of acquired enamel pellicle in vivo by pyrophosphate
Authors: RYKKE MORTEN , RÖLLA GUNNAR
Published: October 2007

Abstract – Soluble pyrophosphate (PP) has been introduced in dentifrices to inhibit the formation of dental calculus. The mechanism of inhibition is probably an adsorption of the pyrophosphate ions to the Ca‐sites on the enamel surfaces and a blocking of the active sites for crystal growth. It has been shown in a recently published study that PP reduced the protein adsorption to hydroxyapatite (HA) in vitro and also inhibited the pellicle formation in vivo. The aim of the present study was to examine the desorption potential of pyrophosphate on the acquired enamel pellicle in vivo. Enamel fragments were carried in the mouth to collect pellicle material and some of the enamel surfaces were then treated with PP. Pellicle formation was examined by SEM of the enamel surfaces. The results showed that pyrophosphate desorbed the acquired enamel pellicle effectively. The clinical consequences of this effect is unknown, but it could possibly explain some aspects of hypersensitivity of teeth observed in some individuals using dentifrices containing PP.
Periodontal disease in children with Down's syndrome
Authors: MODÉER THOMAS , BARR MONICA , DAHLLÖF GÖRAN
Published: October 2007

Abstract – The occurrence of supra‐ and subgingival calculus, gingival inflammation, periodontal pockets ( 5 mm) and alveolar bone loss was determined in children (10‐19 yr) with Down's syndrome (D‐S) and in an aged‐ and sex‐matched control group (n= 39). Of D‐S children (n= 71), 39 of the patients (mean age 15.5 yr) cooperated in a clinical and roentgenologic examination. Alveolar bone loss was determined around incisors and first molars on intraoral radiographs when the distance between cementoenamel junction (GEJ) to alveolar crest (AC) exceeded 2.0 mm. Alveolar bone loss was diagnosed in 39% of the D‐S children compared to 3% in the control group (P<0.001). Of the total number of sites examined on radiographs the distance from CEJ to AC exceeded 2.0 mm in 8% in the D‐S group compared to 0.2% in the control group (P<0.001). The frequency of sites with alveolar bone loss in D‐S children was significantly (P<0.001) higher around the mandibular incisors compared to first molars. The study shows that early signs of periodontitis are frequently seen in D‐S children as early as 11 yr of age and the lesions are first diagnosed in the mandibular anterior region.
Enzymatic hydrolysis of (di)methacrylates and their polymers
Authors: MUNKSGAARD ERIK CHRISTIAN , FREUND METTE
Published: October 2007

Abstract – Di‐ and monomethacrylates hydrolyze to methacrylic acid and the alcohol part at neutral pH catalyzed by an unspecific esterase (hydrolase) and by enzymes in saliva. The rate constants of the enzymatic hydrolysis of various (di)methacrylates increase in the following order: HPMA < BISGMA < LAMA < DECMA < TEGDMA < UEDMA < DEGDMA. Esterase added to aqueous slurries of various powders made of polymerized BISGMA/TEGDMA‐mixtures gave rise to liberation of methacrylic acid, presumably deriving from degradation of those of the dimethacrylates only bonded in the matrix by one end of the molecule. It was estimated that a TEGDMA‐polymer will be hydrolyzed faster than a BISGMA‐polymer. It is proposed that hydrolases in saliva increase the wear rate of composite resin fillings.
Alveolar ridge augmentation by osteoinduction in rats
Authors: PINHOLT ELSE MARIE , BANG GISLE , HAANAES HANS REIDAR
Published: October 2007

Abstract – The purpose of this study was to evaluate bone substitutes for alveolar ridge augmentation by osteoinduction. Allogenic, demineralized, and lyophilized dentin and bone was tested for osteoinductive properties in order to establish an experimental model for further studies. Implantations were performed subperiosteally on the premaxilla and heterotopically in the abdominal muscles of rats. Light microscopic evaluations revealed that all allogenic, demineralized, and lyophilized dentin and bone implants induced new bone formation. No inflammatory or foreign body reactions were observed.