bluuebunny/crossref_metadata_2025_split huggingface dataset:
An in vitro model for studying adsorption of oral streptococci to crown and bridge cements
Authors: ØRSTAVIK JON , ØRSTAVIK DAG 
Published: June 2007

SummaryA sensitive, in vitro method has been developed for the study of bacterial adsorption to dental crown and bridge cements. The method employs heavily radiolabelled cells which adhere to the wall in wells made from the cements. Loss of radioactivity from the bacterial suspension during incubation is used to measure the degree of bacterial adherence to the materials.Strains of Streptococcus sanguis and Streptococcus mutans adhered in greater numbers than a strain of Streptococcus salivarius to both a zinc phosphate cement and a zinc carboxylate cement. The zinc phosphate cement supported adherence to a greater degree than did the zinc carboxylate cement. Pretreatment of the cement surfaces with human saliva tended to reduce bacterial adherence. Pretreatment of the bacteria with saliva slightly enhanced sorption of S. sanguis and S. salivarius, but tended to impair sorption of S. mutans to both types of cements. When both bacteria and cements had been pretreated with saliva, a strong inhibition of the adherence of S. mutans was observed.
Toothpaste abrasive requirements to control naturally stained pellicle
Authors: BAXTER P. M. , DAVIS W. B. , JACKSON J. 
Published: June 2007

SummaryToothpaste abrasivity should be sufficiently high to give effective cleaning without causing mechanical damage to tooth tissue. A clinical trial carried out to measure the cleaning power of calcium carbonate toothpastes of different abrasivity is described; cleaning power is then related to in vitro dentine abrasivity measurements. These findings are used to derive an expression specifying the toothpaste cleaning power which ensures that a chosen low and cosmetically acceptable level of stain is not exceeded providing a consistent daily brushing routine is adhered to.
Jaw muscle fatigue and pains induced by experimental tooth clenching: a review
Authors: CHRISTENSEN L.V. 
Published: June 2007

SummaryMaximal voluntary isometric contractions of the elevator jaw muscles, with the mandible in the position of maximal intercuspation of the natural teeth, can induce fatigue and weak as well as severe pains in the jaw muscles of children and adults. A subjective sensation of muscle fatigue appears after about 0.5 min of clenching, and it seems as if the psychological parameter of fatigue onset to a large, but unknown, extent is determined by the physiological parameter of the amount of isometric contractile activity, and perhaps also the original strength of the muscle; however, also individual psychological factors seem to play a role. Pains in the elevator jaw muscles appear after about 1 min of clenching. Although isometric contractions are necessary to cause onset of jaw muscle pains, it is conceivable that the perception of the moment of onset of pains to a large, but unknown, extent depends on psychological factors, perhaps the intensity of pains; however, also physiological factors may play a role. The severe muscle pains and gradually increasing subjective exhaustion of the elevator jaw muscles can be endured for about 2 min of maximal voluntary tooth clenching. It is suggested that the psychological parameter of muscle endurance to a large, but unknown, extent depends on the physiological parameter of isometric contractile activity, but also individual psychological factors seem to play a role.
Patterns of cortical bone growth around alumina implants
Authors: HOBKIRK J. A. 
Published: June 2007

SummaryIntra‐bony defects are frequently observed around endosseous implants. It has been thought that these are due to occlusal loading and infection. More recently it has been suggested that they may be related to implant shape. This hypothesis has been tested using alumina implants with flat, cone shaped and flared ends, which were inserted into the mandibles and iliac crests of rabbits. The implants remained in situ for up to 18 months and the tissue reaction was studied qualitatively and quantitatively using resin embedded histological sections. New bone was laid down parallel with the implant surface and at a pronounced angle to that in the cortex. Deep intra‐bony defects were seen adjacent to the flared implants and, to a lesser extent, the straight ones. Tapering implants appeared to encourage bone growth on the implant above the level of the cortex.
Mandibular flexure associated with muscle force applied in the retruded axis position
Authors: OMAR R. , WISE M. D. 
Published: June 2007

SummaryThe object of this study was to measure any mandibular flexure occurring in the horizontal plane, when R.A.P. recordings were made with an ‘anterior jig’ (Lucia, 1964), chin‐point guidance and patient‐applied muscle force.The rationale for the experimental method was that any arch‐width change noted at the tooth level reflected a flexure of the mandible.Ten subjects participated and the mean lateral flexure of the mandible in the horizontal plane was 0.073 ± 0.028 mm. As a corollary to the study, mean medial flexure of the mandible in wide opening movements was found to be 0.093 ± 0.044 mm, which was consistent with earlier workers’results.On the basis of the results obtained, restorations constructed to muscle‐R.A.P. recordings could conceivably present as occlusal interferences and, indeed, articulators may require modification so as to allow for mandibular resilience.
Is a low viscosity bonding resin necessary?
Authors: RETIEF D. H. , WOODS E. 
Published: June 2007

SummaryLow viscosity bonding resins have been introduced for use on etched enamel surfaces prior to the application of the viscous composite resins. In this in vitro study the effects of a low viscosity bonding resin on the bond strength, adaptation and microleakage of a composite resin to etched enamel were evaluated. The low viscosity bonding resin did not improve the tensile bond strength of a composite resin to etched enamel, did not increase resin penetration into etched enamel and did not decrease marginal leakage at the composite resin/etched enamel interface. The continued use of low viscosity bonding resins in clinical dentistry is questioned.
The influence of temperature on some physical properties of dental composites
Authors: BAUSCH J. R. , DELANGE C. , DAVIDSON C. L. 
Published: June 2007

SummaryIn this study diametral tensile strength and microhardness of composites were investigated in relation to various temperatures during curing. It has been demonstrated that temperatures elevated up to 60°C can improve the mechanical properties considerably. Also the stability of the resin system in aggressive environments was improved due to more efficient cross‐linking. Thermal analysis of the material showed an endothermic reaction between 60 and 70°C that is believed to be responsible for the initiation of the extra cross‐linking. Heating of composite fillings during clinical use is suggested.
Solubility of enamel powder following treatments with 1% sodium dodecyl sulphate in the presence and absence of fluoride
Authors: GALON E. , FRIEDMAN M. , GEDALIA I. , RAJSTEIN J. 
Published: June 2007

SummaryDeionized water exerts a solubility effect on enamel which is increased in the presence of sodium dodecyl sulphate (SDS), at a concentration used in dentifrices.As expected, incorporation of fluoride by enamel decreases the solubility effect of the detergent in water and acidic buffer. With duration of treatment, the detergent has a lesser effect than demineralized water alone on subsequent solubility of enamel in acidic buffer.
The silent period in the masseter and the anterior temporal muscles at repeated registrations
Authors: FURUYA RYOICHI , HEDEGÅRD BJÖRN 
Published: June 2007

SummaryThree dental nurses took part in an investigation of the reproducibility of the EMG silent period. The latency and duration of the silent period after tooth tapping and jaw jerk were found to be rather stable within the same day and between recordings every other day for 10 days. No differences in the SP variables between right and left side were found. Differences in the latency and duration of the silent period between the masseter and anterior temporal muscles during tooth tapping and jaw jerk were registered. The findings suggest functional difference between the two muscles.
Distribution of stress patterns in the human zygomatic arch and bone
Authors: ALEXANDRIDIS C. , THANOS C. E. , CAPUTO A. A. 
Published: June 2007

SummaryA three‐dimensional photoelastic model was reproduced from a human skull. The insertions of the superficial and deep portions of the masseter muscle and the temporalis fascia were simulated with leather bonded to the appropriate areas. The following loading conditions were employed: (1) bilateral loading of the masseter muscle; and (2) bilateral loading of the masseter muscle together with a bilateral occlusal load. The stress freezing technique was used to lock the resulting stress patterns into the model skull. The stress trajectories were observed and photographed in a circular polariscope.The results suggest that the major stress trajectories to the zygomatic bone and arch follow an alveolo‐maxillary‐zygomatic‐temporal direction. Stresses were highly concentrated in the zygomatic process of the temporal bone. Generally, the stresses were concentrated in those areas of the bone where architectural reinforcement had been demonstrated by other methods.
Thermal conductive analysis of restored teeth by finite element method
Authors: TAKAHASHI NORIAKI 
Published: June 2007

SummaryIn order to clarify the thermal conductive effects of restorative conditions, interpulpal thermal changes of restored vital teeth with inlays and full crowns were analysed theoretically by a finite element method, under thermal irritation from cold and hot drinks. It was concluded that the thermal conductivity of the restorative materials and the thickness of remaining tooth structure both influenced the interpulpal temperatures of restored vital teeth.
Changes in recurrent headache and mandibular dysfunction after treatment with new complete dentures
Authors: MAGNUSSON TOMAS 
Published: June 2007

SummaryThe changes in headache and mandibular dysfunction were studied in a group of forty‐three complete denture wearers 6 months after treatment with new complete dentures. All patients completed a questionnaire and all were subjected to clinical examination of the function of the masticatory system. Eleven of the seventeen patients with recurrent headache reported less frequent headache 6 months after treatment and nine reported that the headache was less severe. There was also a statistically significant reduction of clinical signs of dysfunction of the masticatory system.
Fatigue testing of denture base polymers
Authors: STAFFORD G. D. , LEWIS T. T. , HUGGETT R. 
Published: June 2007

SummaryFatigue characteristics should be an important part of assessment of the behaviour of denture base polymers. Only limited studies have been completed to any extent, largely because of the difficulty in designing suitable machinery. A review of the clinical parameters required in such a machine is discussed, and the development of a multi‐station machine is described, with some preliminary results.
An evaluation of mechanical and adhesive properties of polycarboxylate and glass ionomer cements
Authors: NEGM M. M. , BEECH D. R. , GRANT A. A. 
Published: June 2007

SummaryMechanical and adhesive properties of polycarboxylate and glass ionomer cements were studied. Water had an adverse effect on the compressive and tensile strengths of both materials. Both cements showed good bonding to enamel and dentine. Bonds between polycarboxylate cement and sterling silver were strong enough to cause cohesive failure of the cement rather than adhesive failure, when the specimens were tested. Surface cleaning and conditioning with 5% sodium hypochlorite solution showed an improvement in the bonds of the cements to dentine and they were significantly stronger than the bonds formed after the use of 50% citric acid solution (ASPA conditioner.)
The size of the Balkwill angle and the height of the Bonwill triangle
Authors: OHM E. , SILNESS J. 
Published: June 2007

SummaryThe Balkwill angle and the height of the Bonwill triangle were measured on cephalograms of 128 adult females and males who had all their natural teeth. The size of the Balkwill angle was dependent on the choice of the condylar reference point, whereas the height of the Bonwill triangle was not. When analysed by sex, it was found that the Balkwill angle was larger in males than in females. Likewise, the height of the Bonwill triangle was larger in males.
A clinical re‐examination of patients treated with pinledge‐crowns
Authors: LUNDQVIST P. , NILSON H. 
Published: June 2007

SummaryA group consisting of forty patients received a clinical and radiological re‐examination, of a cross‐sectional type, to examine the effects of pinledge‐crowns on teeth and periodontal tissues.The mean age of the material, which consisted of patients treated at the Department of Prosthetics, University of Umea, during the period February 1969‐November 1971, was 48.6 years (18 ± 22°). In these patients fifty‐one pinledge‐crowns had been inserted, in 88 % of the cases on a canine tooth. In every person, the contralateral tooth served as a control tooth. The teeth were examined with regard to the frequency of failure (expressed as failure rate %/year), the presence of caries, and the periodontal status.The results showed that of the total number of pinledge‐crowns (fifty‐one), twelve had been removed before the time of examination. At the examination it was found that one crown had extensive caries, which required a revision of the crown, and one tooth had a non‐sensitive pulp with a periapical osteitis. These fourteen (27.5%) pinledge‐crowns were classified as failures. The value of the failure rate expressed as %/year was, after 8 years, 3.43 pinledge/year or 3.13, if the patient was used as a unit.Concerning the periodontal effects, the difference between teeth fitted with pinledge‐crowns and control teeth was small.
The influence of experimental interfering occlusal contacts on the postural activity of the anterior temporal and masseter muscles in young adults
Authors: RIISE C. , SHEIKHOLESLAM A. 
Published: June 2007

SummaryThe effects of an intercuspal occlusal interference on the pattern of postural activity of the anterior temporal and masseter muscles were studied in eleven volunteers with complete, natural dentitions. The results indicate that, in man, there is postural activity in the anterior temporal and sometimes in the masseter muscles. The pattern of postural activity is influenced by the occurrence of an experimental occlusal interference, sometimes as early as 1 h after the insertion. After 48 h there was a significant increase of the activity in the anterior temporal muscles. This increased activity persisted until the interference was removed 1 week later and had almost disappeared 1 week after the removal.
The strength of lining materials under constraint
Authors: LLOYD C. H. , JEFFREY I. W. M. , MANNION M. J. P. 
Published: June 2007

SummaryThe compressive strength of the lining material Dycal was found to increase when peripheral constraints were applied to its deformation. The stress required to produce fracture under such circumstances increased with the degree of constraint. In each case, by summing all the stresses in a yield criterion (Von Mises) the strength is understood. Materials previously used with caution because of low (compressive) strength may now be used with more confidence when external support and confinement exists.
Juvenile periodontitis: an historical review
Authors: SAXBY M. S. 
Published: June 2007

SummaryA review of the literature on juvenile periodontitis has been undertaken. This paper traces the historical development of the appreciation of the condition. Some of the numerous early attempts to define a systemic background are noted, and the concept of ‘periodontosis’ and its subsequent influence, e.g. on epidemiological and clinical studies are discussed. The refining over the last 20 years of the concept of aggressive periodontal disease in the young is recorded. The patterns of bone loss in juvenile periodontitis and some forms of treatment are presented, together with evidence on its histopathology. Recent research has tended to concentrate on the microbiology and immunological background of juvenile periodontitis and a number of these studies are discussed.
An in vitro study of caries prevention, cavity adaptation, homogeneity and microleakage of a new fluoride‐releasing resin
Authors: TURPIN‐MAIR J. S. , RAWLS H. R. , CHRISTENSEN L. V. 
Published: June 2007

SummaryA newly developed fluoride‐releasing composite and sealant were tested, in vitro, with regard to homogeneity, cavity adaptation, microleakage, and its effect on the extent of an artificially induced carious attack. Compared with a commercially available composite, the fluoride‐releasing material showed more desirable properties in combating caries, in uniformity of internal structure, and in microleakage.
Occlusal relationship in patients with pain‐dysfunction symptoms in the temporomandibular joints
Authors: De BOEVER J. A. , ADRIAENS P. A. 
Published: June 2007

SummaryA total of 135 patients (thirty‐three males, 102 females) seeking treatment for pain and dysfunction of the TMJ were divided into five subgroups using the clinical dysfunction index of Helkimo.No relation could be found between the number of occluding molars and premolars and the severity of the symptoms nor the evolution of the complaints.A weak correlation was found between the outcome of the treatment with the occlusal splint and occlusal adjustment, and the above mentioned occlusal parameters (r=0.47).
Post‐surgical prosthodontics: clinical notes
Authors: BENINGTON IANC. 
Published: June 2007

SummaryThis paper discusses some of the problems and techniques that are involved in the prosthetic management of patients who are to undergo surgery to the upper and lower jaws. It stresses the importance of a close relationship between the surgeon and the prosthodontist so that the necessary treatment plan may be prescribed pre‐operatively rather than post‐operatively. The dental management where maxillary surgery is anticipated is discussed under the following headings: Pre‐operative assessment; Pre‐operative treatment; The operation; Post‐operative care; The intermediate obturator; The definitive obturator.Where surgery is anticipated in the lower jaw the problems are related to whether the patient has lost all the mandibular bone on one side or only the alveolar section and whether they are able to retain any of the lower teeth to stabilize the appliance. However, even when edentulous, these patients are now able to control their lower appliance much better since the advanced plastic and maxillo‐facial surgical techniques produce a good denture‐bearing area and less mandibular deviation.
The significance of cusps
Authors: LUKE D. A. , LUCAS P. W. 
Published: June 2007

SummaryIt has been argued that the prolonged retention of cusps in the human dentition is a relatively recent aberration due to the negligible abrasiveness of modern diets and that to achieve maximum efficiency and freedom from disease human teeth should be worn down as they are in many herbivorous mammals. Here we critically review the evidence that has been put forward to support this idea and, after discussing the design of occlusal surfaces in relation to the wide variety of mammalian diets, we conclude that cusps are adaptations for breaking food with specific physical properties.
Evaluation of the cytotoxicity of four dental materials in vitro assessed by cell viability and enzyme cytochemistry
Authors: MERYON S. D. , BROWNE R. M. 
Published: June 2007

SummaryThe cytotoxic effects of zinc phosphate and silicate cements, Concise composite and zinc oxide/eugenol were evaluated after 24 h in an in vitro system which simulates the clinical usage of the material, and the results compared with those using phenol. Data of gross changes affecting cell viability placed these materials in ranking order of increasing severity: Concise < zinc phosphate < Silicap ≪ zinc oxide/eugenol. More discrete changes involving alterations in enzyme cytochemistry were assessed and the significance of the results discussed. The presence of dentine powder in the system reduced the cytotoxic effects on these materials.
An investigation of the reproducibility of face‐bow transfers
Authors: GOLD B. R. , SETCHELL D. J. 
Published: June 2007

SummaryAn investigation was conducted to determine the reproducibility of the position of a maxillary cast in two widely‐used semi‐adjustable articulators when a face‐bow transfer was repeated ten times for the same individual.The results obtained with the Dentatus AEB, Whipmix Quickmount and Almore transfer bows were compared. The variations in cast position rarely exceeded ±1.0 mm in any of three planes of space and although the results suggested a ranking in accuracy of the three instruments, all were considered clinically acceptable.On the basis of the results observed, face‐bow transfer appears to be a reliable clinical procedure and accuracy in the determination of reference locations is unlikely to be negated by subsequent transfer errors, provided that appropriate care is employed.
The influence of polishing on the marginal integrity of amalgam restorations
Authors: LETZEL H. , VRIJHOEF M. M. A. 
Published: June 2007

SummaryThe influence of the polishing procedure on the marginal integrity of amalgam restorations was investigated in a clinical study. In this study two operators each made 150 class I or II restorations in a group of forty‐eight adult patients. The restorations were made in a series of six per patient. Within each series, two restorations were made of three different high copper amalgam alloys. Only one restoration of each pair was polished. From each restoration a black and white photograph was taken after finishing and after 0.5, 1.0 and 1.5 years. The marginal integrity of each restoration at the four time periods was quantified with a 6‐point photo rating scale. The quantifications were analysed as to their variance for the factors alloy, polishing procedure, operator and patient.After finishing, all four factors had a significant influence on the marginal integrity. From 0.5 to 1.5 years, the influence of the factors alloy, polishing procedure and patient were very significant. The influence of the patient on marginal integrity was more or less equal to that of the alloy. The size of the polish influence was relatively small. Therefore, it was concluded that the contribution of the polishing procedure to the prevention of marginal deterioration was questionable.
Long‐term influences on marginal fracture of amalgam restorations
Authors: LETZEL H. , VRIJHOEF M. M. A. 
Published: June 2007

SummaryA clinical study was conducted in which two operators made 180 class I or II amalgam restorations in a group of fifty‐seven adult patients. The restorations were made in a series of six per patient. Each restoration was made of a different alloy (five conventional composition alloys and one high copper alloy). During a period of 5 years the marginal fracture formation of all restorations was yearly quantified with a 6‐point photo rating scale. The quantifications were analysed as to their variance for the factors alloy, patient and operator. The relative importance of significant factors was calculated.The results show that for a period of 5 years the alloy, patient and operator all had a significant influence on the marginal fracture formation. The operator influence was stable in time. This factor was relatively small because the operator sample was highly selected. After 1 year the influence of the patient on marginal fracture was equal to that of the alloy. The patient influence in time was stable. However, the alloy influence increased considerably. The longer the service time of the amalgam restoration the more important becomes the influence of the alloy on the marginal fracture formation.