bluuebunny/crossref_metadata_2025_split huggingface dataset:
The long term bonding of a polymeric fissure sealant to stannous fluoride treated enamel
Authors: LOW T. , VON FRAUNHOFER J. A. , WINTER G. B. 
Published: June 2007

SummaryA report is presented of extended studies of tensile bond strength of Nuva Seal to fluoride‐treated enamel 1 week, 3 months and 9 months after application. The differences in strength were not statistically significant. The use of stannous fluoride as the topical agent did not lead to any marked evidence of enamel staining.
Evoked EMG of masseter and temporal muscles in man
Authors: FUJI HIROYUKI 
Published: June 2007

SummaryFollowing a percutaneous stimulation on the mandibular notch skin, two kinds of responses were recorded in the ipsilateral masseter and temporal muscles in man. The two responses had their proper stimulating points. The early response appeared with about a 2 ms latency and the late one with about 6 ms latency which was shorter than that of T wave of the same muscle by about 1 ms. No responses were induced in the contralateral masseter and temporal muscles.Regarding the recovery process of the late response following double stimuli, a testing late response was released about 100% from the effect of conditioning shock at a longer interval than 80∼95 ms. It might be safe to consider that the previous assumption, i.e. those two responses seemed to be M and H waves respectively, had been fortified. H response evoked in muscles tested seems to be sensitive enough to show the difference between excitatory states of its reflex arc.
Removal time: a factor in the accuracy of irreversible hydrocolloid impressions
Authors: KHAKNEGAR BIJAN , ETTINGER RONALD L. 
Published: June 2007

SummaryControversy exists regarding the correct time of removal of an alginate impression from the mouth. to investigate the effect of time of removal on accuracy, a series of alginate impressions were made of the lower left quadrant of a subject having a cast gold crown with four reference marks on tooth No. 19. The impressions were removed from the mouth at 1.5,2,3,4.5 and 7 min after the insertion of the tray. Accuracy of the impressions was assessed by comparing the distances between the reference marks in stone casts with standard measurements taken from the gold crown prior to cementation.Impressions removed at 1.5 and 7 min produced the greatest distoritions buccolingually. For the mesio‐distal lengths all time intervals produced casts which were larger than the standard. The reasons for these findings are discussed and possible explanations are presented.
A 3‐months'study of enzymes as denture cleansers
Authors: BUDTZ‐JÖRGENSEN E. 
Published: June 2007

SummaryIt was the purpose of the study to test the efficacy of dissolvent tablets containing mutanase and protease in removing denture plaque. The study group consisted of forty institutionalized geriatric denture wearers, who were assigned randomly into an enzyme group and a placebo group. Enzyme tablets and placebo for denture soaking were administered by the nurses. The dentures were immersed for 15 min once daily for three months. The amount of denture plaque, the clinical condition of the palatal mucosa, and the concentration of yeasts and bacteria in mucosal and denture smears were recorded before, during, and after the experimental period. The study was designed and carried out as a double‐blind study. After denture soaking for six weeks a significant reduction of the amount of denture plaque and improvement of the clinical condition of the palatal mucosa was recorded. After denture soaking for twelve weeks the conditions had improved further when comparing the enzyme group with the placebo group.
Long term preventive aspects in oral rehabilitation of adults and elderly
Authors: LANGER A. 
Published: June 2007

SummaryPrevention should be regarded as more important for the health than the cure. In adult and geriatric patients prevention is directed towards limiting disability rather than preventing the onset of the disease, since treatment is undertaken after pathological changes have taken place and some degree of invalidity is already present. Oral rehabilitation, if successfully performed, will limit the spread and further deterioration of oral conditions at any developmental stage of a functional pathology. The objective of the rehabilitation should not be the integrity of a single dental arch and certainly not the replacement of the lost teeth. Rather, the principle guiding the treatment should be the achievement of a harmonious functional relation between the maxillary and mandibular jaws, so as to enable them to function in well balanced co‐operation and force distribution. This objective may be best achieved by sensible planning and faultless execution, when the patient is younger, and most of his teeth and their supporting structures are still preserved.
A survey of partial denture design in general dental practice
Authors: BASKER R. M. , DAVENPORT J. C. 
Published: June 2007

SummaryThe objects of this investigation were to discover the methods by which general dental practitioners communicated partial denture designs to dental laboratories and to ascertain the extent to which certain design criteria were being followed. The results of the survey showed that the responsibility for design appeared to be largely delegated to the technician. In most instances cobalt‐chromium dentures were produced which would assist in maintaining oral health; however, this was not the case with acrylic dentures.
Activity of oro‐facial musculature during use of mouthpieces for diving
Authors: INGERVALL BENGT , WARFVINGE JOHAN 
Published: June 2007

SummaryThe EMG activity in the temporal muscle, masseter muscle, and in the lower lip was recorded during 27 minutes use of three makes of mouth‐pieces for air supply during diving. For comparison, recordings were made also of the muscle activity with the mandible in the postural position and during maximal bite. Five male amateur divers, aged 22–35, took part in the investigation.The muscle activity necessary to hold the mouthpiece in position varied from one make of mouthpiece to the other. Compared with the activity with the mandible in the postural position, the activity in the lip increased most, and then considerably, during use of a mouthpiece. Two of the mouthpieces also raised the activity in the masseter muscle. The temporal muscle was affected least and showed an increase in activity during use of only one of the mouthpieces.In the laboratory experiments the muscle activity necessary for retention of the mouthpieces was only a fraction of that during maximal bite. It is stressed, however, that the force with which the mouthpiece is gripped when diving may, owing to emotional factors, be much greater. To avoid undue muscle fatigue and pain it is therefore recommended to use the mouthpiece which, according to the laboratory studies, was shown to require the least muscle activity for retention.
Trauma from occlusion in monkeys
Authors: JOHANSEN JAN R. , KARLSEN KJELL 
Published: June 2007

SummaryTraumatic occlusion was induced in monkeys by insertion of bridges raising the bite. Both incisors and molars were used as abutments. Observation periods ranged from 7 to 24 months. No appreciable effect of the trauma on the apical proliferation of the crevicular epithelium was found. The results were the same in monkeys with or without marginal gingival inflammation before the trauma was induced.
The influence of surface roughness on the retentive ability of two dental luting cements
Authors: ØILO GUDBRAND , JØRGENSEN KNUD DREYER 
Published: June 2007

SummaryTwo series of brass cones and two series of dentine posts with varying surface roughness were produced. Maximum roughness value and arithmetical mean roughness were recorded for each cone. Brass crowns were cemented either with zinc phosphate cement (De Trey's Zinc Cement Improved®) or with polycarboxylate cement (Durelon®). A tensile stress was applied until the crown and the cone separated. The retentive force in relation to retention area was measured.The results showed that the retentive ability of both cements increased with increasing surface roughness. The increase in retention was greater for brass than for dentine. Differences were also found between the two cements; on smooth surfaces the zinc phosphate cement had a lower retentive ability than the polycarboxylate cement, but on rough surfaces the opposite relationship was observed.
Mesurement of lip posture and interaction between lip posture and resting face height
Authors: YEMM R , EL‐SHARKAWY M. , STEPHENS C.D. 
Published: June 2007

SummaryA method for measurement of lip incompetence is described. Electromyographic techniques were used to obtain relaxation of the muscles of the lip and of a jaw elevator muscle. Standardized photographs were taken of the subject's profile, from which lip separation and face height were measured. Variation was found in successive measurements of lip posture, some of which appeared to depend upon mandibular posture. With the teeth in occlusion, lip separation was reduced. Active maintenance of lip contact by the subject was often associated with a reduction in lower face height, which may have been a direct consequence of the lip muscle activity, or of jaw elevator activity facilitating the lip closure.
Bite force and oral function in complete denture wearers
Authors: HARALDSON TORGNY , KARLSSON ULF , CARLSSON GUNNAR E. 
Published: June 2007

SummaryOral function was evaluated in complete denture wearers by using a questionnaire, clinical examination and bite force measurements. Ten patients with satisfactory and ten with unsatisfactory dentures were studied and six of the latter patients were reexamined 1 year after the insertion of new dentures. The bite force values were compared with those obtained in ten dentate controls.No significant differences in bite force were found between the satisfactory and unsatisfactory denture groups. Individual values varied much in both groups. The six patients re‐examined were satisfied with their new dentures and thought they had improved chewing but no significant increase of bite force was found. The maximal bite force was 5–6 times greater in the dentate subjects than in the denture wearers. Edentulous persons are very handicapped in masticatory function and even clinically satisfactory complete dentures are poor substitutes for natural teeth.
The relationship between bruxism and temporomandibular joint dysfunction as shown by computer analysis of nocturnal tooth contact patterns
Authors: TRENOUTH M. J. 
Published: June 2007

SummaryWhilst there are many causes of temporomandibular joint dysfunction, one of the most frequently encountered is bruxism. The two conditions have many aetiological factors in common and there is a rational physiological reason why bruxism could cause temporomandibular joint dysfunction. In fact, experimental bruxism performed under laboratory conditions has been found to cause such joint dysfunction.This contention is supported by direct measurements of nocturnal tooth contact. Patients with temporomandibular joint dysfunction were found to differ from control subjects to a degree which was statistically significant.
Cervical enamel: a danger zone
Authors: DAVIS W. B. 
Published: June 2007

SummaryThe British Standards Institution's document (1974) recommending toothpaste specifications states that ‘There is no evidence that any toothpaste ever produces a level of abrasion causing harm to dental enamel’. This paper questions the assumption that the enamel crown, especially at the cervical margin, is able to cope with modern dietary insult and a ‘good’ oral hygiene regimen, regardless of the enamel abrasivity of the dentifrice used. Once the enamel crown is breached the underlying dentine is sensitive and vulnerable to physical damage. In this work the potential rates of erosive and abrasive loss are related to the thickness of the protective enamel and to the relevance of fluoride treatments for adults. It is suggested that improvements in dental care and an increased tooth life expectancy now make the loss of tooth tissues at the cervical margin more important than is apparent at first sight.
The reproducibility of movement parameters of the empty open—close—clench cycle in man and their dependency on the frequency of movements
Authors: NAEIJE M. , HONéE G.L.J.M. 
Published: June 2007

SummaryThe reproducibility of the empty open‐close‐clench cycle has been investigated. Four subjects were asked three times to perform thirty empty open‐close‐clench movements at each frequency of ½, 1 and 2 cycles s−1.To describe such a series of thirty movements a set of nine parameters were selected. By reference to these parameters it was found that the subjects were not always able to exactly reproduce a series of thirty movements at a repeat test.The movement‐parameters strongly depended on the frequency of the movements. On increasing the frequency the durations of time in which a movement cycle was divided decreased, while the maximum jaw speeds during opening and closing and the jaw speed just before tooth contact increased. The parameter values chosen to describe the smoothness of the movements performed, indicated that the smoother movements were executed at the higher frequencies.
Some subjective‐experiential parameters in experimental tooth clenching in man
Authors: CHRISTENSEN L. V. 
Published: June 2007

SummaryExperimental tooth clenching was performed by fourteen human subjects in order to determine the onset of the subjective sensations of jaw muscle fatigue and jaw muscle pains, the ability to endure jaw muscle pains, and other discomforts. During production of maximal voluntary isometric tension by the elevator jaw muscles the fatigue threshold (x̄= 31 s), the pain threshold (x̄= 55 s), and the pain tolerance (x̄= 118 s) of tooth clenching did not vary significantly intraindividually, whereas this was so interindividually. There might have existed psychological relationships between the three parameters, but they might also have been influenced by the same physiological cause. The weak to intense discomforts were localized to the face, and primarily to the jaw muscles, and after determination of the pain tolerance they disappeared in about 90 s.
Distribution and evaluation of complete dentures in a population in Northern Norway
Authors: NORHEIM PER W. , VALDERHAUG J. JAKOB 
Published: June 2007

SummaryThe frequency and distribution of complete dentures were studied in a population of 358 persons aged 20–69 living in a community in Northern Norway.Among the 83 % who attended the investigation, 49 % had a maxillary and 26 % a mandibular denture. The occurrence of dentures increased with increasing age and with decreasing income and/or social class, while dentures were almost equally common in both sexes, when differences of age and income were taken into account.Of the participants between 50–69 years 39 % had received their first maxillary denture at the age 17–24 years. In the age group 30–49 years the corresponding percentage was 20.Forty‐four percent of the participants had maxillary dentures and 33 % mandibular dentures which were older than 10 years. According to an index on the clinical evaluation of complete dentures as well as to the denture wearers' own opinion, the insufficiency of the dentures tended to increase with increasing age of the dentures. Sex, age, income and social class, however, were found to have only a minor effect on the age and the condition of the dentures as well as on the denture wearers' degree of satisfaction with their dentures. Persons who had natural mandibular teeth, tended to be less satisfied with their maxillary dentures than persons with complete dentures in both jaws.
The structure of experimental in vitro lesions around glass ionomer cement restorations in human teeth
Authors: WESENBERG GRO , HALS EINAR 
Published: June 2007

SummaryClass V cavities were prepared at the amelo‐cementum junction in sixty‐eight extracted human teeth. Fifty‐one were filled with glass ionomer cement (ASPA R′). ‘Secondary carious’ lesions were produced around thirty‐five of the restorations by exposure to acidified gelatin. Thirty‐three teeth served as controls of the effect of the preparation procedure, the conditioner, the ASPA liquid and the filling material proper on the cavity walls.Sixty 120 μm‐thick longitudinal sections from the teeth with the restorations in situ were studied by polarized light microscopy and microradiography.The glass ionomer cement caused by itself a narrow zone of increased radiopacity in the dentine cavity wall. The ‘secondary caries’ pattern consisted of a subsurface outer lesion and a subsurface wall lesion as observed previously in corresponding experi ments with silicate fillings. Outer‐ lesions in enamel were more frequent than with silicate cement.In the cementum all the experimental teeth showed outer lesions. The wall lesions extended only slightly beyond the level of erosion of the restorations. Between the wall lesions (in dentine) or outer lesions (in cementum dentine) and the surface of the cavity wall, a zone of increased radiopacity was found, assumed to be due to reprecipitation of Ca and P promoted by release of fluoride from the filling material.
An in vitro study of marginal leakage associated with composite restorations using an acidified agar technique
Authors: GRIEVE A. R. , GLYNJONES J. C. 
Published: June 2007

SummaryThe marginal leakage associated with a composite restorative material was examined using an in vitro method for the production of secondary caries‐like lesions after the restorations had been subjected to thermal cycling. The fillings were placed in cavities with a 90° cavo‐surface angle with and without etching of the walls with phosphoric acid and in cavities with a bevelled margin which were also acid etched. Some degree of leakage was demonstrated in 95% of the unetched cavities while approximately half of the restorations in etched unbevelled cavities showed leakage. With the bevelled and etched group virtually no leakage occurred.
The surface structure of the temporomandibular joint disk: a scanning electron microscopic study
Authors: JAGGER R. G. 
Published: June 2007

SummaryThe surface appearance of seven temporomandibular joint disks obtained at postmortem has been studied by scanning electron microscopy. Two of the disks had lateral perforations which corresponded, in position, to macroscopic changes in the condylar and temporal joint components.The nature of the disk surfaces has been described. The central portion of the disks consisted of tightly bound collagen bundles; the bundles of the anterior and posterior parts were more loosely bound and irregularly orientated.The implications of the findings have been discussed in terms of articular function and dysfunction and of disease processes within the joint.
The use of differential scanning calorimetry for the evaluation of dental materials
Authors: McCABE J. F. , WILSON H. J. 
Published: June 2007

SummaryThe presence of thermal transitions within the working range of denture base polymers may have a drastic effect on the dimensional stability of the material. The glass transition temperatures of fifteen denture base polymers have been measured and their significance discussed. The effect of thermal contraction and polymerization contraction on dimensional stability is not fully understood at the present time. An attempt has been made to explain the dimensional changes which occur in denture bases with the aid of transition temperatures and inferred thermal contraction and polymerization contraction values.
Microporosity in bis‐glycidyl methacrylate films
Authors: WILLIAMS B. , von FRAUNHOFER J. A. 
Published: June 2007

SummaryThe existence of hitherto unsuspected micropores in fissure sealant films (bis‐glycidyl methacrylate resin films) has been demonstrated by means of scanning electron microscopy. Immersion of specimens in various ionic solutions showed that the defects in the surface of the resin film tended to become filled with the passage of time.
Book reviews
Authors: FRANKS A. S. T. , WILSON H. J. , FOSTER T. D. , WADE O. L. , STENGELHOFEN J. 
Published: June 2007

Books reviewed in this article. Temporo‐Mandibular Joint: Function and Dysfunction ED. By G. A. Zarb and G. E. Carlsson. An Outline of Dental Materials and their Selection Ed. by William J. O'Brien and Gunnar Ryge A Colour Atlas of Clinical Conditions in Paedodontics Ed. by Robert Rapp and Gerald B. Winter. Lecture Notes on Drugs for Dental Students Ed. by T. J. Wilkin and P. N. Davidson. A Career in Speech Pathology Ed. by Charles Van Riper.
The management of patients with severe hypodontia
Authors: HOBKIRK J. A. , BROOK A. H. 
Published: June 2007

SummarySevere hypodontia is thought to be caused by hereditary and environmental factors. It has a population incidence of 0.3% in the permanent dentition, being much rarer in the deciduous dentition. The management of patients suffering from this condition is described, including the use of conservative, prosthodontic and orthodontic procedures.
Some electromyographic parameters of experimental tooth clenching in children
Authors: CHRISTENSEN L.V. 
Published: June 2007

SummaryTwelve children exercised maximal voluntary tooth clenching until pains appeared (pain threshold) in the right masseter muscle and could no longer be endured (pain tolerance). Concomitantly the integrated electrical activity of the muscle was determined as a ratio of the isometric is muscle exercises. It is possible that the two exercises were accompanied by progressive muscle fatigue. While changes in the pain threshold could not be related to similar changes in the accompanying electrical muscle activity, the pain tolerance seemed to increase with a decrease in electrical muscle activity. To a large, but unknown, extent the pain threshold might have depended on psychological factors, rather than electrical muscle activity, whereas the pain tolerance to a large, but unknown, extent might have depended on the electrical muscle activity. The muscle activity of the two subjective tests might have been influenced by the same physiological determinants, e.g. progressive muscle fatigue and ischaemia of the muscle tissue. The number of teeth in contact during the isometric muscle exercises and the size of the gonial angle of the mandible did not influence either the pain threshold and pain tolerance or the muscle activity of these tests.
Pulpal response to a temporary crown and bridge material in ferret teeth
Authors: TOBIAS ROSALIND S. 
Published: June 2007

SummaryThe histological effects of a temporary crown and bridge material (Scutan) on the pulp of canine teeth of ferrets was investigated at time intervals up to 6 months. After 24 h a moderate to severe pulpal response was observed which persisted up to 6 months. A case of contact sensitivity to Scutan is reported.
Behaviour of teeth under various loading conditions with finite element method
Authors: TAKAHASHI NORIAKI , KITAGAMI TETSUYA , KOMORI TOMIO 
Published: June 2007

SummaryA study was made of behaviour of the upper central incisor, lower second premolar and lower first molar under various loading conditions, with the finite element method. Analysis was made of tooth deflections, rotational centre, stresses in the periodontal membrane, turning moments of tooth and supporting forces of the periodontal membrane.It was shown that the horizontal vector of load was much more influential to the teeth than the vertical vector, and that effects of the loading angle on the tooth behaviour were found most markedly in the lower first molar, followed by the lower second premolar and upper central incisor in decreasing order.