bluuebunny/crossref_metadata_2025 huggingface dataset:
Elastic outward bending of loaded buccal and lingual premolar walls in relation to cavity size and form
Authors: GRANATH LARS , SVENSSON ALVAR
Published: October 2007

Abstract— The aim was to study effects of the size and form of the occlusal part of Class II cavities on elastic outward bending during loading of buccal and lingual walls, separated by the preparation. Twenty newly extracted caries‐free premolars were used. A special arrangement for standardized cavity preparation was set up. In order to obtain accurate measurements of the outward bending of loaded cavity walls, an electronic tensile test device was constructed. Methodologic studies showed an insignificant departure from linearity between outward bending and load. All deformation was elastic. Correction factors were determined for strain of the apparatus as well as for indentation in the tooth substance. Measurement accuracy was calculated to ±0.12 N for force and ±0.2 μm for movement. In accordance with statistical principles, a few outlying measurements were discarded. The outward bending of buccal and lingual walls of cavities suitable for conservative restoration with dental amalgam was about 0.15 μm per Newton. Outward bending increased dramatically with exaggerated cavity depth and width. In the light of present knowledge of average chewing forces and tooth contacts in the habitual intercuspal position in young dentate adults, there seems to be little risk of leakage between conservative restorations and cavity walls as a result of elastic outward bending, though the risk certainly does increase with the depth and width of the cavity.
Purification and characterization of a 65‐kilodalton diisopropylfluorophosphate‐binding protein in the outer membrane of Fusobacterium nucleatum Fev1
Authors: BROKSTAD KARL A. , JENSEN HARALD B.
Published: October 2007

Abstract— A 65‐kilodalton protein was identified in the outer membrane of Fusobacterium nucleatum Fevl by SDS‐PAGE. The relative amount of the protein varied during growth, being greatest in stationary phase. The protein was radio‐labeled by [125I]‐lactoperoxidase treatment of live cells and was only partially cxtractable with 2% sodium dodecylsulfatc (SDS) at room temperature, and therefore assumed to be both exposed to the cell surface and peptidoglycan associated. In intact cells the protein bound diisopropylfluorophosphate (DFP), indicating that it may be a serine protease. DFP‐binding activity depended apparently on proper localization of the proteins in the membrane. Several methods were tried in attempts to purify the 65‐kilodalton protein; the method that gave best results was preparative SDS‐polyacrylamide gel electrophoresis. The isoelectric point was determined to about pH 5. Amino acid composition analysis showed that the 65‐kilodalton protein possesses an excess of hydrophilic over hydrophobic residues, polarity index 52%. The N‐terminal end of the protein was apparently blocked.
Effects of chemically modified starches in suspensions and lozenges on pH of human dental plaque
Authors: LINGSTRÖM PETER , BJÖRCK INGER , DREWS ANDERS , BIRKHED DOWEN
Published: October 2007

Abstract— The aim was to evaluate chemically modified starches (CMS) from a cariologic point of view as alternatives to gum arabic in sugar‐free lozenges. Two commercial CMS, Purity Gum 40 and Capsul, were selected due to their comparatively low availability to alpha‐amylase in vitro. Both gelatinized CMS suspensions and lozenges were tested in vivo by measuring plaque pH. The results showed that suspensions of Purity Gum 40 or Capsul were less available to alpha‐amylase in vitro than the soluble starch reference. However, the initial phase of amylolysis was comparatively rapid also with CMS. In spite of the slower rate of hydrolysis, suspensions of the two CMS reduced pH of dental plaque in vivo to the same extent as soluble starch, but somewhat less compared with glucose. Lozenges with Purity Gum 40 also lowered plaque pH, although less than when administered as a precooked suspension. The most prominent pH drop was found with a lozenge containing Purity Gum 40‐sucrosc‐glucose, while tablets with gum arabic‐maltitol and pectin‐gelatine‐Lycasin somewhat increased the pH values. To conclude, it is not recommended to exchange gum arabic for CMS in sugar‐free lozenges, since the cariogenic properties of the products are negatively affected.
Characterization of fibrin(ogen) fragments in gingival crevicular fluid
Authors: TALONPOIKA JUHA
Published: October 2007

Abstract— Crevicular fluid (CF) samples were collected by paper strips from healthy and diseased sites. The molecular distribution of fibrin and fibronectin in CF and plasma samples was investigated using SDS‐polyacrylamide gel electrophoresis and specific immunoglobulins. Intact fibrin was found in all CF samples. In addition several bands with both lower and higher molecular weights than intact fibrin were seen. These bands were not present in the plasma samples. The low molecular weight bands are suggested to represent degradation products of fibrin. The high molecular bands could be fibrin‐fibronectin complexes or fragments of large fibrin polymers. Fibronectin degradation products, but not intact fibronectin, were seen in both healthy and diseased samples.
Alveolar ridge augmentation in rats by combined hydroxylapatite and osteoinductive material
Authors: PINHOLT ELSE MARIE , BANG GISLE , HAANAES HANS REIDAR
Published: October 2007

Abstract— The purpose of this study was to examine if increased bony ingrowth developed when hydroxylapatite was implanted together with an osteoinductive substrate. Dense hydroxylapatite granules (HA) (Calcitite, Calcitek, San Diego, CA, USA) were mixed with equal volumes of allogenic, demineralized, lyophilized dentin or bone and implanted subperiosteally for alveolar ridge augmentation purposes and heterotopically in the abdominal muscles in rats. Light microscopic evaluation revealed that HA was surrounded by fibrous connective tissue containing foreign body giant cells and it had neither an osteoinductive nor an osteoconductive effect. The newly formed bone induced from the implanted allogenic, demineralized, lyophilized dentin or bone was never found in close contact with the HA and did not incorporate the implant.
Release of fluoride from light cured lining materials
Authors: HÖRSTED‐BINDSLEV PREBEN , LARSEN MOGENS JOOST
Published: October 2007

Abstract— Fluoride was extracted from 0.3 ml samples of five different light cured lining materials. From two brands, fluoride concentrations ranging from 5 to 10 ppm were quickly established and maintained. From three other brands only very small amounts of fluoride were released. The fluoride released was related to the possible caries preventive effect.
Organic content in occlusal groove‐fossa‐system in unerupted 3rd mandibular molars: a light and electron microscopic study
Authors: EKSTRAND KIM RUD , WESTERGAARD JYTTE , THYLSTRUP ANDERS
Published: October 2007

Abstract— A method is described by means of which organic content in fissure areas of 12 unerupted 3rd mandibular molars can be prepared for studies in the light microscope (LM) and in the transmission electron microscope (TEM). Thus, LM and TEM examinations revealed that the organic content throughout the fissure in bone‐covered and in mucosa‐covered 3rd molars with uncompleted root formation consists of cells belonging to the enamel organ in late or in postmaturative stages. In mucosa‐covered teeth with completed root formation it was only possible to identify enamel organ cells at the entrance of the fissure. Deeper parts were occupied by degenerative cells, polymorphonuclear cells and unidentified material. The results indicate that ameloblasts in fissures do not transform to stratified squamous epithelium but gradually degenerate towards terminal stages and remain as such, as the tooth emerges into the oral cavity.
Combined effects of Zn2+‐chlorhexidine and Zn2+‐cetylpyridinium chloride on caries incidence in partially desalivated rats
Authors: GIERTSEN ELIN , BOWEN WILLIAM H. , PEARSON SYLVIA K.
Published: October 2007

Abstract— The effects of Zn2+ combined with either chlorhexidine or cetylpyridinium chloride (CPC) on caries incidence in partially desalivated rats were investigated. Seven groups of 12 animals each received topical applications for 20 s with a saturated swab (0.2 ml) of the following aqueous solutions twice daily on weekdays (10 a.m. and 3 p.m.) and once daily during weekends (12 a.m.) for 5 wk: deionized water (placebo); 40 mM zinc acetate; 2.2 mM chlorhexidine diacetate; 4.4 mM CPC; 40 mM zinc acetate and 2.2 mM chlorhexidine diacetate; 40 mM zinc acetate and 4.4 mM CPC; and 20 mM NaF (positive control). Coronal caries was scored by the method of Keyes. All treatments except CPC alone resulted in significantly (P<0.05, ANOVA) less smooth‐surface caries than did the placebo. NaF treatment resulted in significantly less smooth‐surface caries than did Zn2+, chlorhexidine, CPC, and Zn2+ ‐CPC. The inclusion of zinc ions did not significantly increase the caries‐inhibitory efficacy of chlorhexidine (CH). The combination of Zn2+ ‐CPC decreased smooth‐surface scores significantly more than did CPC alone. Significant differences in sulcal‐surface caries were not observed among the groups. Zn2+‐CPC suppressed the Streptococcus sobrinus counts significantly more than did the separate agents. Animals treated with Zn2+ ‐CH harbored the lowest populations of S. sobrinus.
Oral sugar clearance in elderly people with prosthodontic reconstructions
Authors: HASE JAN C. , BIRKHED DOWEN
Published: October 2007

Abstract— The aim was to study oral sugar clearance in elderly individuals, around 70 yr of age, with various types of prosthodontic reconstructions. Salivary glucose concentration was measured under the tongue after chewing a glucose tablet in four groups of individuals with: 1) complete dentures (CD) (n= 19), 2) removable partial dentures (RPD) (n= 22), 3) fixed partial dentures (FPD) (n= 24), and 4) no dentures (controls) (n = 23). Salivary glucose clearance was also studied after a mouthrinse with 10% glucose in 18 of the 19 individuals with CD and in 13 of the 22 with RPD both with and without the dentures. Saliva samples for glucose analysis were taken, in this part of the experiment, at two separate locations: under the tongue and in the labial vestibule near the mandibular right first molar. After the tablet intake, the group with CD showed the highest initial salivary glucose concentration, the longest oral sugar clearance time and the largest area under the curve, followed by the group with RPD. FPD did not seem to influence the oral sugar clearance. After the glucose rinse, higher values for the various clearance variables were obtained in the vestibule than under the tongue and, to some extent, when the experiments were carried out with than without the dentures. Thus, the results from this study indicate that removable dentures, especially CD, contribute to less effective oral sugar clearance in elderly people and that the oral clearance seems to be more dependent on the site than on the presence or absence of removable dentures in the oral cavity.
Hypochlorous acid induced activation of human neutrophil and gingival crevicular fluid collagenase can be inhibited by ascorbate
Authors: SUOMALAINEN KIMMO , SORSA TIMO , LINDY OTSO , SAARI HERKKO , KONTTINEN YRJÖ T. , UITTO VELI‐JUKKA
Published: October 2007

Abstract— Interstitial collagenase either obtained from human neutrophils by phorbol myristate acetate (PMA) induced degranulation or isolated from human gingival crevicular fluid was found to be activated by addition of an oxidative agent, hypochlorous acid (HOCl). Collagenase released by PMA stimulated neutrophils was completely in latent form but underwent partial autoactivation during 16 h incubation at 22°C in the presence of soy bean trypsin inhibitor. The partial autoactivation was potentiated to complete activation of released collagenase after addition of exogenous HOCl. Ascorbate prevented this activation of neutrophil collagenase. Isolated human gingival crevicular fluid collagenase represented an apparent Mr of 70 kD in completely latent form, whereas 70/54 kD enzyme species were detected for partially autoactive form of the enzyme. Western blot analysis of gingival crevicular fluid using a polyclonal antibody raised against purified human neutrophil collagenase revealed the same 70/54 kD molecular forms of the enzyme. The latent gingival crevicular fluid collagenase was also activated by HOCl and this activation could be prevented by ascorbate. Activation of the 70 kD latent collagenase by HOCl as well as by other non‐proteolytic activators such as an organomercurial compound (phenylmercuric chloride) and a gold (I) compound (gold thioglucose) was not associated with detectable changes in apparent Mr, whereas trypsin activation resulted in fragmentation of 70 kD enzyme to 54 kD species. Our results provide further evidence for the neutrophil origin of gingival crevicular fluid collagenase and suggest that, in addition to proteolytic activation, oxidative and antioxidative agents seem to be able to regulate neutrophil collagenase activity.
In vitro antibacterial effect of chlorhexidine added to glass‐ionomer cements
Authors: RIBEIRO JULIANA , ERICSON DAN
Published: October 2007

Abstract— The aims of the present study were to investigate the antibacterial properties of glass‐ionomer cements containing different concentrations of chlorhexidine and the possible release of chlorhexidine from the compound. Chlorhexidine gluconate or diacetate was mixed with glass‐ionomer cements and tested in vitro against strains of Lactobacillus casei and mutans streptococci. A spectrophotometric test was used to monitor the release of chlorhexidine from the mixture. In a broth culture test, the higher the concentrations of chlorhexidine in the mixture, the longer the time of antibacterial effect on Streptococcus mutans and the greater the tendency of the material to deteriorate. Agar diffusion tests revealed bacterial inhibition in a dose‐response manner. The tested bacterial strains were similarly inhibited and the antibacterial properties decreased with time. A minor portion of added chlorhexidine was released from the cement. The deterioration of the cements indicates that the material could be useful as a varnish‐like chlorhexidine carrier.
Effects of a chlorhexidine‐fluoride‐strontium rinsing program on caries, gingivitis and some salivary bacteria among Finnish school children
Authors: SPETS‐HAPPONEN SATU , LUOMA HEIKKI , FORSS HELENA , KENTALA JUKKA , ALALUUSUA SATU , LUOMA ANJA‐RIITTA , GRÖNROOS LISA , SYVÅOJA SIRKKU , TAPANINEN HELENA , HAPPONEN PERTTI
Published: October 2007

Abstract – In order to find out if it is possible to prevent caries and gingivitis by periodical use of chlorhexidine‐fluoride mouthrinses with or without strontium, and to find out what effects they have on salivary mutans streptococci and lactobacilli counts, a total of 243 schoolchildren aged 11 yr with high DMFS scores were randomly divided into four groups. One group (C) served as a basic control. Subjects in the second group (GXF) rinsed their mouths twice a day every third week with a rinsing solution containing 0.05% chlorhexidine gluconate and 0.04% NaF. In the third group (CXFS) the rinsing solution contained 500 ppm Sr during the first and second year and 15 ppm during the last 6 months, in addition to chlorhexidine and fluoride. In the fourth group (CX) the solution contained only 0.05% chlorhexidine gluconate. All the rinsing solutions had pH 5.8 buffered with succinic acid‐NaOH buffer. After 2 yr and 9 months, the mean DMFS (SD) increments in the C, GXF, GXFS, and GX groups were 3.8 (5.7), 2.5 (3.2), 3.5 (4.8), and 3.4 (5.5), respectively. The percentage of subjects with bleeding gingival units had decreased from initial to final values as follows: C, 81–38; GXF, 88–42; GXFS, 89–56; GX, 89–37. The number of lactobacilli and mutans streptococci in saliva remained virtually unchanged throughout the study. For caries increment and gingival bleeding, the differences between groups were not statistically significant. The chlorhexidine‐fluoride combination tended to prevent caries, but the effect on gingival bleeding and salivary counts of mutans streptococci and lactobacilli was negligible.
Alveolar ridge augmentation in rats by Bio‐Oss
Authors: PINHOLT ELSE MARIE , BANG GISLE , HAANAES HANS REIDAR
Published: October 2007

Abstract – The purpose of the study was to examine if Bio‐Oss initiated osteoinduction or osteoconduction when implanted into rats. Sintered and unsintered granules of the anorganic bovine bone Bio‐Oss was implanted subperiosteally for alveolar ridge augmentation purposes and heterotopically in the abdominal muscles of rats. Light microscopic evaluation revealed no osteoinduction or osteoconduction in connection with sintered or unsintered Bio‐Oss. A foreign body reaction was observed around both forms.
Corrosion investigation of two materials for implant supraconstructions coupled to a titanium implant
Authors: RAVNHOLT GERT , JENSEN JOHN
Published: October 2007

Abstract – The corrosion of two materials for implant supraconstructions, a carbon fiber/PMMA composite and a silver‐palladium alloy, was investigated in vitro, the materials being galvanically coupled to a titanium implant. Corrosion current and pH of the electrolyte were monitored, and corrosion products were identified by powder X‐ray diffraction. The carbon composite and the silver‐palladium per se did not corrode, whereas a silver‐palladium specimen brazed with the recommended brazing alloy corroded unmistakably, yielding copper‐containing corrosion products. The action of local corrosion cells around the brazed joint is considered, and it is concluded that the two materials seem well suited for implant supraconstructions, provided that brazing the silver‐palladium can be avoided. Considering the clinical relevance of the experimental model used, it is concluded that the model is likely to predict a lower corrosion susceptibility than the one found in vivo.
Radix paramolaris in permanent mandibular molars: identification and morphology
Authors: CARLSEN OLE , ALEXANDERSEN VERNER
Published: October 2007

Abstract – The Royal Dental College, Copenhagen, houses an extensive collection of human teeth which have been extracted in Denmark. The collection presently includes 203 permanent mandibular molars with a root complex containing a facially‐located supernumerary root. This macrostructure is named radix paramolaris (RP). By analyzing the large number of specimens available it was possible to establish uniform and precise criteria for the identification of RP on M1 inf, M2 inf, and M3 inf The analyses included both separate and non‐separate RP. The representation of the RP variants according to tooth type was mapped. Furthermore, the following clinically relevant variables with respect to RP were registered: degree of separation, divergence, apical bend, apical gracility, and fusion. Because of the nature of the material, the study was mostly qualitative and non‐metric. The results are aimed primarily at clinical dentists, dental morphologists, and dental anthropologists.
Morphometric analysis of occlusal groove‐fossa‐system in mandibular third molar
Authors: EKSTRAND KIM RUD , GARLSEN OLE , THYLSTRUP ANDERS
Published: October 2007

Abstract – Based on serially cut 200‐μm‐thick sections from 21 human mandibular third molars, a quantitative characterization was made of the morphology in the mesial and distal interlobal groove. Two parameters were used: depth of interlobal groove and structure angle. The interlobal groove depth varied between 0.13 and 0.55, taken in relation to the maximum crown height. The structure angle varied between 2° and 170°. If the structure angle was ≤25°, the interlobal groove was classified as a fissure; if the angle was >25°, the interlobal groove was classified as a groove. Only in 18% of the sections did the interlobal groove manifest itself as a fissure. The study demonstrates that it was possible unambiguously to describe the two‐dimensional profile of interlobal grooves by groove depth and structure angle.
Saliva composition and caries development in asthmatic patients treated with β2‐adrenoceptor agonists: a 4‐year follow‐up study
Authors: RYBERG MATS , MÖLLER GHRISTIAN , ERIGSON THORILD
Published: October 2007

Abstract – In an earlier study, we found that chronic treatment with β2‐adrenoceptor agonists in asthmatic subjects gave an impaired saliva secretion and a higher caries prevalence than in healthy controls. Twenty‐one of the asthmatics and their matched controls were examined 4 yr later in a follow‐up study. Samples of whole saliva stimulated by chewing and parotid saliva stimulated by citric acid were collected and dental caries was scored. In the asthmatic group the secretory rates of stimulated whole and parotid saliva decreased by 20% and 35%, respectively, compared to the control group. The number of lactobacilli increased. The asthmatic subjects had a decreased output per minute of total protein, amylase, hexosamine, salivary peroxidase, lysozymc, secretory IgA, a bacteria‐aggregating glycoprotein, potassium, and calcium in stimulated parotid saliva. Initial and manifest caries lesions as well as the number of DFS were significantly increased in the asthma group. We conclude that asthmatic patients treated with β2‐adrenoccptor agonists have an increased caries susceptibility due to an impaired saliva secretion caused by the use of β‐adrenergic agonists.
Temporalis and masseter muscle activity in patients with anterior open bite and craniomandibular disorders
Authors: BAKKE MERETE , MIGHLER LARS
Published: October 2007

Abstract – Activity in temporalis and masseter muscles, and traits of facial morphology and occlusal stability were studied in 22 patients (19 women, 3 men; 15–45 yr of age) with anterior open bite and symptoms and signs of craniomandibular disorders. Facial morphology was assessed by profile radiographs, occlusal stability by tooth contacts, and craniomandibular function by clinical and radiological examination. Electromyographic activity was recorded by surface electrodes after primary treatment with a reflex‐releasing, stabilizing splint. Maximal voluntary contraction was reduced compared to reference values, particularly in subjects with muscular affection, but maximal activity increased significantly when biting on the splint. Maximal voluntary contraction was positively correlated to molar contact and negatively to anterior face height, mandibular inclination, vertical jaw relation and gonial angle. Relative loading of the muscles was markedly increased during resting posture. It was concluded that reduced occlusal stability and long‐face morphology were associated with weak elevator muscle activity with disposition overload and tenderness. The results also indicated that increase of occlusal stability might lead to increased muscle strength and possibly reduce risk of physical strain.
Incidence of adverse effects of dental materials
Authors: KALLUS THOMAS , MJÖR IVAR A.
Published: October 2007

Abstract – Acute and long‐standing adverse effects from dental materials used in the treatment of 13 325 patients in 15 820 appointments were recorded by 137 dentists. Twenty‐four suspected side effects were reported by the patients and 22 by the clinicians; 7 were classified as “probable” or “possible” acute reactions and 15 as long‐standing effects, 13 being “verified” and 2 “probable”. In another survey, 31 dentists representing a total of 387 years of practice recollected 113 patients with side effects from dental materials.
Marginal fit of porcelain and indirect composite laminate veneers under in vitro conditions
Authors: HARASANI MUNIR H. , ISIDOR FLEMMING , KAABER SVEND
Published: October 2007

Abstract – The purpose of the present study was to compare the marginal adaptation of indirect composite and porcelain veneers in vitro using transmitted‐light microscopy. A preparation with a marginal chamber finish for a veneer was performed on 10 extracted molars after which 5 composite and 5 porcelain veneers were made and fitted using self‐ and light‐cured microfill composite resin. Three longitudinal and 3 horizontal sections were cut in each preparation with a diamond saw and were ground to a thickness of approximately 150 μm and investigated under the light microscope. Although the absolute marginal discrepancy at the cervical location had the highest statistical significance in the composite veneer group, the composite and porcelain veneers, in general, demonstrated a similar absolute marginal discrepancy and thickness of luting agent with average values from 50 μm to 195 μm for the two parameters. A considerable amount of excess of luting agent was furthermore observed in both groups of veneers, being most pronounced in the composite veneers.
Occlusal control of mandibular elevator muscles
Authors: Bakke Merete , Michler Lars , Möller Eigild
Published: October 2007

Occlusal stability and mandibular elevator muscle function was studied in 25 women (20–30 yr of age). They had 27–32 fully erupted teeth with few treated occlusal surfaces, and craniomandibular function including mandibular mobility was normal. The aim was to analyze the influence of natural patterns of occlusal contact on electromyographic activity, unaffected by pain and functional disorders. Occlusal stability was assessed in the intercuspal and in lateral contact positions as the number of teeth with physical contact and the number of opposing pairs of teeth in contact. Electromyographic activity was recorded by surface electrodes over anterior and posterior temporalis and masseter muscles. In general, positive correlations were found between occlusal stability in intercuspal position and moderate to strong static and dynamic contractions, most significant in masseter muscles, indicating that forceful contraction of these muscles implies stable occlusion. Systematically, the duration of activity during chewing was negatively correlated with occlusal stability in the intercuspal position, most pronounced in working‐side muscles. This pointed to shorter contractions with stable occlusion and is interpreted as the result of less need for stabilizing activity. It is concluded, that the correlations between occlusal stability and elevator muscle function are probably based on feedback mechanisms from periodontal pressoreceptors.
Crevicular IgG antibodies and recovery of Streptococcus mutans implanted by mouthrinsing
Authors: Camling E. , Gahnberg L. , Emilson C. G. , Lindquist B.
Published: October 2007

After challenge with a streptomycin‐resistant strain of Streptococcus mutans (S. mutans), a tendency to higher recovery of S. mutans was found in gingival crevicular fluid (GCF) from surfaces with a low IgG antibody activity against S. mutans than in GCF from surfaces with a high antibody activity. This suggests that antibodies in GCF may interfere with the establishment of S. mutans on gingival tooth surfaces. In GCF collected from some sites, considerably higher IgG antibody activity was observed than in homologous serum, indicating that part of the IgG response to S. mutans was locally derived.
Physiologic variation of sucrase activity and microbial counts in human saliva
Authors: Karjalainen Sara , Karjalainen Mikko , Forrester Donald
Published: October 2007

Quantitation of salivary sucrase activity has been proposed as a method for the estimation of the level of sucrose consumption. The purpose of the present study was to investigate the physiologic variability of the sucrase activity and microbial counts in paraffin‐wax‐stimulated saliva of subjects with sound sucrose consumption habits. Variation was analyzed by repeated sampling studies. Intraday variability was investigated by serial analyses of 16 individuals who gave eight samples at 2‐h intervals on a single day. Interday variation was studied by analyzing the morning value of 24 individuals on three consecutive days. Interday variability of salivary mutans streptococci, lactobacilli, and yeasts was tested using semiquantitative commercial test kits. The diurnal variation of sucrase activity revealed that the activity in the morning was significantly higher than at noon or at later sampling times of the day. Interday variation was considerable in subjects with high sucrase values. The day‐to‐day variability of the salivary microbes was considerable for lactobacilli and relatively small for yeasts. A weak positive correlation ranging from 0.732 to 0.741 was found between high sucrase activity values and salivary lactobacilli. Salivary samples should be collected in the morning to differentiate between subjects with high and low sucrase activities.
Personal computer equipment for dental digital subtraction radiography vs. industrial computer equipment and conventional radiography
Authors: Möystad Anne , Svanæs Dagfinn B. , Larheim Tore A.
Published: October 2007

A “low‐cost” personal computer (PC) system used to digitize dental radiographs was tested by assessing the accuracy of its subtraction images versus those of “high‐cost” industrial equipment and conventional radiography. Subtraction images were made of artificial lesions in human femur bone and subsequently evaluated by students and teachers. The observations were analyzed in terms of true positive and false positive reports. “Low‐cost” and “high‐cost” subtraction images revealed only small differences in diagnostic accuracy. Compared to conventional radiography, the diagnostic accuracy of the subtraction images with the “low‐cost” PC system was significantly higher for all observers. The interexaminer variance was similar for the subtraction and the conventional images for both students and teachers, except for a significantly reduced interexaminer variance for the teachers concerning the true positive reports with the “low‐cost” PC subtraction technique.
Three‐year evaluation of effect of surface conditioning on bonding of glass ionomer cement in cervical abrasion lesions
Authors: van Dijken Jan
Published: October 2007

Cervical abrasion/erosion lesions were restored without any form of mechanical cavity preparation with an anhydrous glass ionomer cement. To study the effect of dentin pretreatment on the bonding between dentin and glass ionomer cement three cleaning methods were tested: 1) mechanical cleaning with a prophylaxis paste, 2) scrubbing with a surface active cavity cleanser (Tubulicid) for 60 seconds, or 3) a 10–15 s application of a 40% polyacrylic acid solution. During a 3‐yr period, 193 restorations were evaluated every 6 months. Cumulative loss rates after 3 yr were 11.6%, 12.3%, and 17.9% respectively. One restoration showed secondary caries during the evaluation period.
Sweets and other sugary products tend to be the primary etiologic factors in dental caries
Authors: Sundin Birgitta , Granath Lars
Published: October 2007

The aim of this study was to analyze the relationships between caries incidence and each of seven caries‐related factors in a group of 15‐ to 18‐yr‐olds as well as in single and combined subgroups representing favorable or less favorable fractions of six of the factors. Sixty‐nine 18‐yr‐olds were interviewed about consumption of sweets and other sugar‐containing products during the past 3 yr and examined for oral hygiene, salivary counts of mulans streptococci and lactobacilli, salivary flow rate and oral sugar clearance time at the ages of 15 and 18. Simple linear correlations and a stepwise multiple regression analysis were used to compare ranks and explanatory values. The highest correlations were obtained for intake of sweets and intake of other sugary products, with r values increasing from 0.25 and 0.16, respectively, in the total material to 0.70 and 0.67 in less favorable fractions of oral hygiene, salivary flow rate and other sugary products in the former case, sweets in the latter. The stepwise multiple regression analysis revealed that sweets and other sugary products contributed 12 percentage points to the total explanatory value, which was as low as 19%.
Caries associated microflora in plaque from orthodontic appliances retained with glass ionomer cement
Authors: Hallgren Anders , Oliveby Anette , Twetman Svante
Published: October 2007

The caries associated microflora in dental plaque adjacent to orthodontic brackets retained with a glass ionomer cement (GIC) and a resin based composite was investigated using the split‐mouth technique. 3, 8, and 28 days after the onset of the appliances, 48‐h‐old plaque was sampled. An increasing prevalence of mutans streptococci and lactobacilli in plaque from both retaining materials was found. A tendency to colonize more frequently around the composite retained brackets was noticed for both types of bacteria. The proportion of mutans streptococci in relation to the total viable count was significantly higher in plaque samples from composite retained brackets compared to GIC retained 1 month after onset of treatment. The results suggest that a less caries inducing microflora may develop when GIC is used as luting agent in orthodontic dentistry.
Diagnosis of dentin involvement in occlusal caries based on visual and radiographic examination of the teeth
Authors: Nytun Riviane B. , Raadal Magne , Espelid Ivar
Published: October 2007

The purpose of the present study was to examine the validity of visual, radio‐graphic and combined visual‐radiographic examination of occlusal caries, with special reference to the diagnosis of dentin lesions, using the microscopic diagnosis after sectioning the teeth as validating criterion. Thirty extracted permanent molar teeth with signs of occlusal caries were selected and radiographed using a standard method similar to bitewing. Ten dentists, five from the Department of Cariology and Endodontics and five from the Department of Pedodontics, were asked to make a visual, radiographic and combined visual‐radiographic caries examination with an interval of at least 1 month between different examinations. The teeth were sectioned bucco‐lingually and the caries assessed as enamel or dentin lesion in a stereomicroscope. The sensitivity/specificity of the diagnoses of dentin lesions was 0.72/0.41 for the visual, 0.66/0.50 for the radiographic, and 0.86/0.64 for the combined visual‐radiographic examinations. The Receiver Operating Characteristic (ROC) method revealed a statistically significant difference between combined visual‐radiographic examination and the two other, but not between the isolated visual or radiographic examination. It is concluded that the combined use of visual and radiographic examination is belter than either visual or radiographic examination alone.
Epstein‐Barr virus (EBV) genomes and c‐myc oncogene in oral Burkitt's lymphomas
Authors: Syrjänen Stina , Kallio Pekka , Sainio Pertti , Fuju Chang , Syrjänen Kari
Published: October 2007

In addition to Burkitt's lymphomas, tentative evidence suggests the involvement of Epstein‐Barr virus (EBV) in malignant lymphomas of T‐cell origin. The c‐myc proto‐oncogene is strongly associated with the development of lymphoid neoplasias. In the present study, a series of 38 biopsies of oral lymphomas (29 Burkitt's lymphomas, 9 malignant lymphomas of other type) obtained from patients in Tanzania were studied using in situ hybridization (ISH) and polymerase chain reaction (PCR) for detection of EBV DNA and c‐myc oncogene. In ISH applied on formalin‐fixed, paraffin wax‐embedded biopsies, the Bam HI W fragment of EBV DNA was used as the probe. Amplification of c‐myc oncogene was studied by PCR with a primer set from Exon II area. As an internal standard (β‐globin gene was simultaneously amplified. EBV DNA was disclosed by ISH in five Burkitt's lymphomas only. Using the PCR, 20 of the 29 cases (70%) of Burkitt's lymphomas showed amplification for EBV DNA. Of the other EBV‐positive lymphomas, two were of the lymphocytic type (large non‐cleaved cell), one histiocytic and one Burkitt's‐like lymphoma. All EBV‐positive cases found on the agarose gel were positive also with the dot blot, when hybridized with the 32P‐labeled EBV Bam HI W‐fragment probe. All lymphomas showed similar bands on the gel for c‐myc and β‐globin indicating that no amplification of c‐myc was present.
Permeability of protective gloves to (di)methacrylates in resinous dental materials
Authors: Munksgaard Erik Christian
Published: October 2007

Dentists may develop contact allergy induced by handling resinous dental materials, and vinyl and latex gloves may provide protection against the monomers of these materials only during the time it takes for a monomer to permeate the glove. The passage times and rates of penetration of four commonly used (di)methacrylates ‐ HEMA, TEGDMA, BISGMA, and UEDMA ‐ for 11 protective gloves were measured. The passage time for HEMA and TEGDMA through vinyl gloves was 1–3 min, and around 20 min for BISGMA and UEDMA. The rate of penetration of HEMA and TEGDMA in vinyl gloves was 0.5–4.5 μmol · min−1· cm−2. The passage time of HEMA and TEGDMA through most of the latex or the modified latex gloves was 5–8 min and the rate of penetration 0.5–3.1 μmol · min−1· cm−2. Latex or modified latex gloves provide a protection against BISGMA and UEDMA for 80 min or more with one exception (Elastyrene), which burst after about 50 min in contact with the resins. Of the tested gloves Ansell, Neutralon, Mediglove, and Biogel D provide protection against HEMA and TEGDMA for at least 5 min.
Effect of stannous fluoride and tetracycline on periodontal repair after delayed tooth replantation in dogs
Authors: Selvig Knut A. , Bjorvatn Kjell , Bogle Gary C. , Wikesjö Ulf M. E.
Published: October 2007

Previous studies have indicated that inflammatory resorption and ankylosis, which are frequent sequela after delayed tooth replantation, can be greatly reduced by treating the root surface with 1% solutions of stannous fluoride and tetracycline. However, the SnF2 conditioning leaves a long‐standing inflammatory reaction in the periodontal ligament. To examine whether a more dilute SnF2 solution would reduce postoperative inflammation without jeopardizing any beneficial effects, anterior teeth in three young adult beagles were extracted and allowed to air‐dry for 45 min. They were then immersed in 0.1% SnF2 for 5 min, rinsed in saline, immersed in 1% doxycycline HC1 for 5 min, rinsed, and replanted. Control teeth were air‐dried and replanted without further treatment. Block biopsies were harvested after 4 wk of healing and processed for histometric analysis. In experimental teeth, 85% of the root surface area showed normal healing, compared to 33% in control teeth. Conversely, resorption and ankylosis were more frequent in controls than in experimental teeth. A persisting inflammatory reaction either adjacent to or at a distance from the root surface was seen in limited areas in both experimental and control teeth. Compared to preceding studies, the findings indicate that reducing the strength of the SnF2 solution from 1% to 0.1% may result in less persistent inflammation, at the cost, however, of less complete prevention of inflammatory resorption and ankylosis.
Evidence for xylitol 5‐P production in human dental plaque
Authors: Waaler Sonni Mette
Published: October 2007

The Turku sugar studies indicated that xylitol may possess a caries‐therapeutic effect. More recent data show that xylitol exhibits a bacteriostatic activity on a wide range of bacteria based on uptake and expulsion of xylitol. Intracellular xylitol 5‐P appears to be a key substance associated with inhibition of bacterial metabolism by xylitol. This has been shown in studies with pure strains of bacteria, mainly Streptococcus mutans. The aim of the present study was to examine if production of xylitol 5‐P occurs in freshly collected dental plaque which is exposed to labeled xylitol. Plaque extracts were analyzed by thin‐layer chromatography combined with autoradiography and high performance liquid chromatography. Strong indications were obtained that xylitol 5‐P is readily produced by dental plaque. No other significant xylitol metabolites were identified. The bacteriostatic properties of xylitol in plaque are a mechanism which may well account for the caries‐therapeutic effect of xylitol.
Relationship of collagenase and cathepsin G activity in gingival crevicular fluid
Authors: Suomalainen Kimmo
Published: October 2007

Human neutrophil cathepsin G has been identified as a potent proteolytic activator of latent human neutrophil collagenase in vitro. In order to examine the role of cathepsin G in the activation mechanism of latent human neutrophil collagenase in vivo, gingival crevicular fluid was collected from periodontal pockets of patients with adult periodontitis and the relationship of cathepsin G to the proportion of endogenously active collagenase and total collagenase activity was determined. The changes in these parameters were monitored before and after periodontal therapy and compared to control values obtained for periodontal sites without clinical signs of inflammation or increased pocket depth. A significant decrease in cathepsin G and collagenase activity in gingival crevicular fluid collected from initially deep periodontal pockets was observed in response to scaling and root planing (P < 0.025, Wilcoxon signed rank test). Also the proportion of endogenously active collagenase decreased (P < 0.05). There was a significant correlation of cathepsin G and total collagenase activity. However, no correlation of cathepsin G activity and endogenously active collagenase was observed. The results indicate the existence of several distinct activation pathways for latent human neutrophil collagenase in vivo and suggest that, apart from cathepsin G, other proteolytic activation cascades and/or non‐proteolytic activaton pathways participate in the activation of latent human neutrophil collagenase in vivo.
Five‐year study of cervical erosions restored with resin and dentin‐bonding agent
Authors: Hansen Erik Keith
Published: October 2007

The cumulative retention rate of a microfilled resin in non‐undercut cervical abrasion/erosion lesions was studied over a 5‐yr period. The enamel was etched and the dentin was pretreated with either Gluma (n= 75) or the first marketed version of Scotchbond (n= 30). The cumulative 5‐yr retention rate of the Gluma fillings was 90% and that of the Scotchbond fillings 47% (the 95% confidence limits were 83–98% for Gluma fillings and 27–67% for Scotchbond fillings). The retention rate with both bonding agents was significantly higher in the maxillary arch than in the mandibular arch.
Significance of epidemiologic research in the understanding of periodontal disease
Authors: Ainamo Juke
Published: October 2007

This review describes the development of periodonlal index systems which during the last 50 yr have made it possible to gradually expand our understanding of the etiology and pathogenesis of periodontal diseases. Modern epidemiologic research on the prevalence and severity of periodontal diseases is based on a substantial amount of scientific data collected since the early 1940's. The work of a number of innovative researchers has eventually resulted in the clarification of one unsolved problem after the other. At the same time new ideas have been developed for the inclusion of public health aspects in the epidemiologic analyses. The assessment of periodontal treatment needs has become an issue of great importance in many countries of the world and has initiated a discussion and studies on the role of the possibilities for self‐assessment of treatment needs. A completely new area of interest has developed when recent epidemiologic surveys demonstrated a substantial increase in the numbers of elderly people together with a substantial increase in the number of teeth per elderly person
Policy and research in oral health care
Authors: Petersen Poul Erik , Hoist Dorthe
Published: October 2007

The purpose of the paper is to highlight the interrelationship between social and health policy, and health services research. The principles and concepts in social and health policy in the Scandinavian welfare states are described with reference to oral health care. The concept of policy analysis is defined and distinctions are made between “analysis of policy”, and “analysis for policy”. The policy perspective is discussed with the focus on the planning ‐ budgeting ‐ implementation ‐ evaluation cycle and related to the WHO Strategy for Health for All. Finally, the implications for oral health services research in Scandinavia are emphasized.
Health services research in oral health care: an empirical example
Authors: Holst Dorthe , Petersen Poul Erik , Grytten Jostein
Published: October 2007

Health services research is mainly applied research which can contribute to the production of knowledge necessary to appropriate decisions in health care. As an example, a study of the occurrence of tooth extractions is presented. Two hypotheses were tested: a negative relationship between provider density and consumer income, and the probability of tooth extractions and the number of teeth extracted, conditional upon extraction. A nationwide sample of 1286 non‐institutionalized Norwegians 20 yr and above was interviewed by a public survey institute. The data were analyzed using a two‐part model including logistic regression and multiple regression analysis. One third of the sample had had a tooth extraction during the last 5 yr. The majority of the sample had few teeth extracted at the time of extraction. The probability of tooth extraction was related to provider density and not to consumer income. The number of teeth extracted was related neither to provider density nor to income. Tooth extraction was not related to age. Some policy implications are discussed.
Human pulpal response to direct filling gold restorations
Authors: Johansson G. , Bergman M. , Anneroth G. , Eskafi M.
Published: October 2007

Class V cavities were prepared in 47 caries‐free premolars intended to be extracted for orthodontic reasons. A powdered gold filling material, Goldent, which can be hand condensed, was used for direct fillings. The following test groups were used: (A) cavity preparation, no filling, (B) cavity filled with Goldent only, (C) cavity lined with Tubulitec and filled with Goldent, (D) cavity with Goldent filling, sealed with IRM, and (E) positive and negative controls. The teeth were extracted after 1–200 days and the pulpal response was histologically examined. The results revealed that only in Group B, i.e. when the cavity was filled with Goldent, was the risk of a pulpal reaction obvious, although the material per se (Group D) did not influence the pulpal tissue to any serious degree. Probably the Goldent material cannot provide a marginal seal tight enough to prevent microleakage, allowing microorganisms to give rise to pulp damage and inflammation. In those cases where the cavity had been isolated with Tubulitec liner before the gold restoration was made, the pulp was effectively protected from damage caused by microorganisms.
Adaptation of dental plaque to sorbitol after 3 months' exposure to chewing gum
Authors: Waaler Sonni Mette , Rölla Gunnar , Assev Synnöve
Published: October 2007

Five subjects used sorbitol‐containing chewing gum for a period of 12 wk. Plaque was collected before and after the sorbitol exposure and also 12 wk after the termination of the exposure. The individual plaque samples were incubated with 14C‐labeled sorbitol, and the medium was examined by HPLC. It was found that plaque samples from all subjects catabolized more sorbitol after the exposure. The flora adapted to sorbitol was persistent, and all the subjects had a higher capacity for metabolizing sorbitol even 12 wk after the end of the sorbitol exposure than before it. Formate, acetate, ethanol, and lactate were the major catabolites of sorbitol. Small amounts of succinate and propionate were found in some samples.