bluuebunny/crossref_metadata_2025_split huggingface dataset:
Horizontal stabilization of upper and lower borders of the comfortable zone
Authors: TRYDE GERD , STOLTZE K. , BRILL N. 
Published: June 2007

SummaryUsing a screw jack device the upper and lower borders of the comfortable zone were recorded in a two step procedure designed to counteract bias inherent in previous measurements. In these measurements, successively increasing and decreasing values of zonal borders were recorded corresponding to a fully closed or fully opened starting position of the screw. Both of these positions are outside the comfortable zone. The two step procedure used a starting position which was supposed to lie inside the comfortable zone. However, the procedure did not achieve its aim fully. It succeeded only in stabilizing the lower border values. In the discussion hypothetical considerations are made concerning theneurophysiological mechanism underlying recordings of the borders of the comfortable zone, which might explain the differential behaviour of the zonal borders.
In vitro studies of fluoridated amalgam
Authors: HURST P.S. , von FRAUNHOFER J.A. 
Published: June 2007

SummaryFour types of fluoridated amalgam were assessed in vitro in terms of fluoride release, corrosion behaviour and compressive strength, and compared with amalgams prepared from the corresponding non‐fluoridated alloys. Although corrosion susceptibility was found to be increased, steady release of the fluoride ion was demonstrated over a 16‐week period, indicating that fluoridated amalgams might be prophylactically employed in clinical dentistry as a means of overcoming the problem of secondary caries associated with amalgam restorations.
Does a temperature gradient exist across the mucogingival junction?
Authors: BRILL N. , MAEDA T. , STOLTZE K. 
Published: June 2007

SummaryOn the assumption that the colour difference between attached gingiva and alveolar mucosa is accompanied by a temperature difference, twenty subjects with a high standard of oral health were studied. Five points on either side of the mucogingival junction were examined by means of a thermocouple probe. A mean difference amounting to about 2/3°C was found between the surface temperatures of the two structures.
Tissue hypersensitivity to dental materials
Authors: DAHL B. L. 
Published: June 2007

SummaryFive cases of tissue hypersensitivity to Scutan and two to Impregum are reported. The reaction to Scutan was a burning sensation in the mucosa in contact with the material, followed by swelling and erythematous ulcers producing heavy discomfort. All symptoms gradually disappeared after removal of the material. To Impregum the reaction was basically the same, only less vigorous since contact with the material is of limited duration. All the cases were women in the menopause. Attention is drawn to the possibility of hormonal imbalance being a factor of importance in the development of hypersensitivity reactions to materials of this sort.
Viscoelastic properties of elastomeric impression materials: polysulphide, silicone and polyether rubbers
Authors: TOLLEY L. G. , CRAIG R. G. 
Published: June 2007

SummaryCreep compliance measurements were shown to be effective in characterizing the elastic, retarded elastic, and viscous properties of polysulphide, silicone, and polyether impression materials. The test is particularly valuable in that the creep compliance was independent of load, allowing the mechanical properties to be represented by a single total creep compliance curve which can be used to determine the various creep components. The total recovered compliance was shown to be independent of time provided the polymerization had progressed sufficiently before testing was done. The retarded elastic and viscous compliances contributed proportionally to the total creep compliance and thus did not affect the rankings of materials. The viscous compliance of polysulphide A decreased enough after 1 h so that the creep compliance of A and D were not different. The creep compliance measurements showed that the polysulphide materials were the most viscoelastic followed by silicone and polyether impression materials. The polyether was the most nearly ideal elastic material but it had a flexibility comparable to heavy body polysulphide. Of particular interest was the observation that polyether with thinner in ratios up to 1 : 1 by length had no practical effect on the viscoelastic properties.
Ultra‐violet absorption by two ultra‐violet activated sealantss
Authors: YOUNG K. C. , MAIN C. , GILLESPIE F. C. , STEPHEN K. W. 
Published: June 2007

SummarySince the ability of u.v. setting pit and fissure sealants to set in depth is dependent on the penetration of the u.v. radiation, the absorption coefficients of Nuva‐seal and Alphaseal were determined at 365 nm, the wavelength of radiation used to polymerise both materials. Nuva‐seal and Alphaseal had absorption coefficients of 0·165 mm −1 and 6·25 mm −1, respectively. The u.v. fluorescent dye present in Alphaseal contributed 2·5 mm −1 to its absorption coefficient and the remaining absorption was due to the 5% w/w catalyst concentration present, since the basic resin had no significant absorption. Therefore Nuva‐seal may set adequately to the depths required of fissure sealants, but Alphaseal may not, unless a very high intensity u.v. source is used. A reduction in the catalyst concentration and the removal of the u.v. fluorescent dye might improve the setting characteristics of Alphaseal.
The effect of finishing on the anodic polarization of high‐copper amalgams
Authors: BOYER DANIEL B. , CHAN KAI CHIU , SVARE CARL W. , BRAMSON JAMES B. 
Published: June 2007

SummaryThe influence of surface finishing procedures on the corrodibility of high‐copper amalgams was measured. Anodic polarization curves were determined in Ringer's solution for amalgam samples made from a dispersion and a ternary alloy. Three types of finishes were compared: as carved, burnished, and polished.The polarization curves of the burnished and polished specimens were statistically similar (P > 0·05) at all potentials investigated. The carved samples exhibited higher corrosion currents at most of the potentials investigated.
Size of variables in mandibular movements in autopsy material
Authors: RASMUSSEN OLE COLLIN 
Published: June 2007

SummaryAutopsy was performed on the right temporomandibular joint in eleven individuals with a mean age of 71 years. Standard positions indicative for protrusion, laterotrusive border movement and posterior opening movement were photographed in the sagittal plane. Size of movements of the disc and condylar head were recorded, as well as movements of a reference point in the mental region. The slope of the anterior discal movement was estimated and mandibular rotation during posterior opening was registered. Centre of rotation during the hinge movement was in all cases located to the craniodorsal part of the condylar head. Attempt to construct centres of rotation in the eminence and condylar head for the horizontal movements was in vain. The discussion deals with the influence of the specific kind of material on the results and the possible systematic differences to clinical material.
Split cast discrepancies and arbitrary axis dental cast articulator mounting
Authors: LAING D.P. , WISE M.D. 
Published: June 2007

SummaryThs split cast technique has been advocated as a useful clinical tool for checking the reproducibility of jaw registrations. As originally described it requires the use of a kinematic face bow. Since the arbitrary axis used with the Whip‐Mix face bow has been demonstrated to be close to that of the kinematic axis, it is feasible that the split cast technique could be used with such a face bow. Casts of ten subjects were mounted with retruded jaw registrations, made at different degrees of vertical separation. The upper casts were mounted using both kinematic and arbitrary face bow transfers, and the accuracy of mating of the split components measured.With the arbitrary face bow, the components of the split cast system only mated when repeated registrations were of exactly the same thickness, i.e. the same vertical dimension. Small differences in vertical dimensions produced the largest errors at the split. Any slight variations in the thickness of the retruded registrations will therefore invalidate the use of the split cast method in conjunction with an arbitrary face bow.The importance of the correct spatial relationship of mounted dental casts for the adequate diagnosis and treatment of a variety of oral and associated masticatory system disturbances is well documented (Lucia, 1961; Lucia, 1964; Celenza, 1973). However, accurate execution of the clinical and laboratory stages is necessary if the required information is to be obtained from articulated casts.
The cavity sealing ability of composite restorations subjected to thermal stress
Authors: KIDD EDWINA A. M. , HARRINGTON E. , GRIEVE A.R. 
Published: June 2007

SummaryAn artificial caries technique, using a diffusion controlled acidified gel, was used to create in vitro artificial lesions adjacent to composite restorations. Prior to gel immersion, test specimens were temperature‐cycled in a machine designed specifically for this purpose. Examination of control specimens showed little evidence of leakage, the presence of a cavity wall lesion being used as an indication of leakage. Compared to the controls, the test specimens showed either a reduction or no change in leakage pattern. It is suggested that thermal percolation may not be of clinical significance in relation to composite restorations.
The adaptation of composite materials to etched enamel surfaces
Authors: LOW T. , LEEand K.W. , VON FRAUNHOFER J. A. 
Published: June 2007

SummaryThe adaptation of three composite materials and one unfilled bis‐GMA resin to etched enamel surfaces was investigated by examining under optical and scanning electron microscopy the adhesive‐enamel junction of replicas. The length of the tags and the density of tagging observed on the replicas showed that the three composite materials, Adaptic, Concise and Delphic, adapted to the etched enamel surface equally as well as the unfilled resin Nuva Seal. The results of this study together with available results of mechanical testing and clinical studies allow the conclusion that the successful retention of the composite filling materials to an etched enamel surface is not dependent on the use of an intermediate unfilled resin or bonding agent.
Tissue conditioners as functional impression materials
Authors: MCCARTHY J.A. , MOSER J.B. 
Published: June 2007

SummaryThe adaptation of three composite materials and one unfilled bis‐GMA resin to etched enamel surfaces was investigated by examining under optical and scanning electron microscopy the adhesive‐enamel junction of replicas. The length of the tags and the density of tagging observed on the replicas showed that the three composite materials, Adaptic, Concise and Delphic, adapted to the etched enamel surface equally as well as the unfilled resin Nuva Seal. The results of this study together with available results of mechanical testing and clinical studies allow the conclusion that the successful retention of the composite filling materials to an etched enamel surface is not dependent on the use of an intermediate unfilled resin or bonding agent.
The convergence angle in teeth prepared for artificial crowns
Authors: OHM E. , SILNESS J. 
Published: June 2007

SummaryThe bucco‐lingual and mesio‐distal convergence angles in vital and rootfilled teeth prepared for complete crowns were measured microscopically on 190 stone dies. In vital teeth the mean convergence angles varied between approximately 19 and 27 degrees. In rootfilled teeth the mean angles varied between 12 and 37.
A methodological study of errors in vertical measurements of edentulous ridge height on orthopantomographic radiograms
Authors: RAMSTAD TORE , HENSTEN‐PETTERSEN ODD , MOHN ERIK , IBRAHIM SAMIRA I. 
Published: June 2007

SummaryThe purpose of this methodological investigation was to study the relative magnitude of the various errors in vertical ridge measurements from orthopantomograms of edentulous patients.The study was divided into two parts, Part I and Part II. Part I included eleven patients. Two standard orthopantomograms were taken of each patient. Part II included five of the eleven patients in Part I. Here, a third X‐ray taken with the mouth open was added to the X‐rays from Part I. The X‐rays were traced by three dentists.Twelve vertical measurements in the maxilla and in the mandible were made. The variance produced by the patients (morphological variance) and those produced by the dentist, the X‐ray, the interaction patient‐dentist, the interaction dentist‐X‐ray and the random variance (methodological variances) were separately estimated on the basis of a three‐way mixed analysis of variance model.In Part I, on the average, the sum of the methodological variances constituted 1·7 % and 2·5 % of the total variance in the maxilla and in the mandible respectively. The X‐ray produced the greatest single variance component, averaging 1·1 % in both jaws. Although generally statistically significant, the remaining methodological variances were of low magnitude. The interaction patient‐dentist, however, was not significant in most cases.In Part II, on the average, the sum of the methodological variances increased to 38·8 % in the maxilla and 4·6 % in the mandible, mainly caused by an increase in the variance produced by the X‐ray.
Reproducibility of the normalized electromyographic recordings of the masseter muscle by using the EMG recording during maximal clenching as a standard
Authors: HOSMAN H. , NAEIJE M. 
Published: June 2007

SummaryA method of normalizing the integrated EMG recordings from the masseter muscles is introduced. For each subject investigated the maximal clenching force is remarkably constant and reproducible. This makes it possible to normalize the integrated EMG recordings to the EMG activity at the maximal clenching force without having to measure this force at the beginning of every experiment. These normalized integrated EMG activities give a good quantitative impression of the static force exerted by the masseter muscle, and therefore can be compared quantitatively over several experiments. The relationship between the normalized integrated EMG activities and the clenching force is linear up to approximately 80% of the maximal clenching force.
The effect of placement of cervical margins of class II amalgam restorations on plaque accumulation and gingival health
Authors: GULLO C.A.O. , POWELL R.N. 
Published: June 2007

SummaryThe effects of restoring early proximal carious lesions were investigated in a series of thirty‐six surfaces. In eighteen lesions the cervical margins of the restorations extended subgingivally, and in eighteen the margins were located supragingivally. Three months after restoration, plaque accumulation was not significantly different from pre‐restoration levels. The degree of gingival inflammation showed a significant improvement after restoration where cervical margins were finished supragingivally (P < 0.5). Where margins were finished subgingivally a highly significant deterioration in gingival health occurred (P < 0.1).
Offsetting the increased plaque formation in partial denture wearers by tooth brushing
Authors: EL GHAMRAWY ESSAM , RUNOV J. 
Published: June 2007

SummaryIn two experiments, each running for 2 weeks, plaque formation was studied on forty‐two teeth acting as abutments for removable partial dentures. In the first experiment, only ordinary tooth brushing was practised. Plaque accumulation was rapid, yielding scores ranging between 2 and 5. In the second experiment, following instruction in intensive tooth brushing, plaque scores were depressed to approximately 1.5 and below.
Plaque accumulation following the wearing of different types of removable partial dentures
Authors: ADDY M. , BATES J.F. 
Published: June 2007

SummaryA group of forty‐five patients took part in a study to assess the effects of wearing partial dentures upon the accumulation of plaque in the mouth in the absence of oral hygiene. The wearing of a partial denture resulted in a significant increase in plaque accumulation and this increase was the result of a significant increase in both buccal and lingual plaque. Furthermore in a group of ten patients a small, but significant, increase in plaque occurred in the opposing arch during the wearing of the dentures. The accumulation of plaque on the buccal aspect of the teeth appeared unrelated to the type of denture worn. However, significantly more plaque accumulated on the lingual aspect of all the teeth in those patients wearing lower plate dentures as opposed to lower bar dentures. In the 3 day study periods only a small increase in plaque occurred on the palatal aspect of the upper anterior teeth not covered by any part of the partial denture and no significant increase occurred on the lingual aspect of the lower anterior teeth not covered by the partial denture. A highly significant increase occurred on the lingual aspect of lower anterior teeth covered by the lingual plate of the partial denture. Overall the wearing of a denture day and night resulted in more plaque accumulation compared with day only wearing of dentures. However considering the denture types this significant increase was not apparent in the lower plate dentures. The results provide further evidence of the potentially adverse effect partial dentures may have upon the supporting structures of the teeth when oral hygiene procedures carried out by the patient are inadequate.
The sagittal condylar movements of the clicking temporomandibular joint
Authors: VAN WILLIGEN J. 
Published: June 2007

SummaryAn analysis of the sagittal condylar pathways in patients with clicking temporomandibular joints is presented in relation to the mechanism of this symptom which is still hypothetical. The condylar movements of five healthy subjects are compared with the pathways of five patients with unilateral or bilateral clicking joints. The results indicate that in the latter group there are clearly perceivable deviations from the movement pattern as found in the group of the healthy subjects.
A comparison of dentine abrasion data generated by radiotracer and surface profilometer methods
Authors: DAVIS W. B. 
Published: June 2007

SummarySix toothpastes were despatched to two research stations where a radiotracer method of dentine abrasion measurement is used (British Standards, 1974; Hefferren, 1976) and three research stations where a surface profile method is used (Ashmore, Van Abbé & Wilson, 1972).Each station measured the abrasivities of the pastes with respect to dentine by their own method.The ranges of abrasion data were found to be wider from the surface profile method than from the radiotracer method.
Clinical study of a heat‐cured silicone soft lining material
Authors: MÄKILÄ EINO , HONKA OSMO 
Published: June 2007

SummaryThirty‐seven mandibular dentures lined with Molloplast B silicone material were examined after they had been worn for 2–8 weeks and 6, 18 and 30 months. The denture wearers were also examined and interviewed.The colour was found to have become lighter in 46% and turned yellow or brown in 51 %; the denture base had worn through in 24% and there was a failure on bond in 22%; no hardening of the material was noted; 24% of the dentures had broken. An unusual taste was reported by 22% and smell by 14% of the denture wearers; mucosal soreness was noted in 14%; denture stomatitis developed in 48%; hygiene was poor in 61 % and fungal growth was traced in 81 % of the dentures; 73 % of the patients were satisfied with the soft lining.
Mucosal temperature rises following long‐term use of full dentures
Authors: MAEDA T. , STOLTZE K. , USER A. , KROONE H. , JENSEN K. E. , BRILL N. 
Published: June 2007

SummaryMucosal temperatures were studied in twenty‐two subjects, who had worn full upper and lower dentures for at least 5 years. By comparing with a group of twenty‐two fully dentate subjects, it was found that in the denture wearers, temperatures were increased significantly in the lower jaw, but not in the upper jaw.
The resistance of superficially sealed enamel to wear and carious attack in vitro
Authors: DAVIDSON C. L. , BEKKE‐HOEKSTRA I. S. 
Published: June 2007

SummaryThe resistance to wear and carious attack has been investigated in vitro for enamel that has been subjected to several stages of the sealing procedure: etching, etching and remineralization in whole saliva and etching followed by sealing. After partial mechanical removal of the sealant, the remaining surface enamel proved to be resistant to carious attack as long as the resin tags were present. An estimation is made of the thickness of the affected layer. Pretreatment with monofluorophosphate has proved to influence the extent of the histological changes due to etching. A discussion on these phenomena is given.
Tissue accumulation of nickel released due to electrochemical corrosion of non‐precious dental casting alloys
Authors: BERGMAN M. , BERGMAN B. , SöREMARK R. 
Published: June 2007

SummarySpecimens of four non‐precious dental casting alloys intended for use in the ceramicmetal technique were implanted subcutaneously in the neck region of mice. The animals were killed after 5 months. Organs and tissues were tested as regards the concentration of nickel by means of atomic absorption spectrophotometry. The study showed that due to electrochemical corrosion nickel was released from implants and accumulated in some tissues and organs.
Tear energy of elastomers for maxillofacial applications
Authors: GOLDBERG A. JON , CRAIG ROBERT G. , FILISKO FRANK E. 
Published: June 2007

SummaryThe energy necessary to generate a unit area of torn surface was measured for six elastomers with low moduli of elasticity. Four polyurethane materials and two commercial maxillofacial materials were included. The latter had tear energy values between 0.63 and 6.56 erg/cm2, while the polyurethanes ranged from 8.49 to 50.0 erg/cm2. Three of the materials demonstrated non‐Hookian behaviour during testing, violating an assumption of the tear energy analysis. A method of compensating for this discrepancy is described.
X‐ray diffraction and fluoride analysis of enamel powder treated with concentrated phosphoric acid containing sodium fluoride
Authors: GEDALIA I. , BAHAREV H. , KOCHAVI D. 
Published: June 2007

SummaryReaction products of enamel powder treated with concentrated phosphoric acid (30% and 50%) containing 0.5‐2% NaF were examined by X‐ray diffraction and fluoride determination.Fluoride concentration increased according to the level of NaF in the acid; the uptake was highest in the enamel treated with the less concentrated acid.Hydroxyapatite and fluoridated apatite, dicalcium phosphate are the major reaction products. CaF2 was present in all samples; the amount was reduced at the lowest fluoride concentration (0.5% NaF).