bluuebunny/crossref_metadata_2025_split huggingface dataset:
Duration patterns of percussion sound in healthy and periodontally affected teeth
Authors: TAGUCHI S. , SUGITA N. , ASAZUMA Y. , HARA K. 
Published: June 2007

SummaryTen periodontally affected subjects and 10 healthy subjects were selected in order to examine the duration patterns of percussion sounds in all upper teeth, excluding the 8′s.Probing depth, loss of attachment, tooth mobility by ‘Periotest’, bone loss and percussion sound duration via occlusal sound analyser were recorded during the pretreatment period.The following results were obtained from the study:

the normal duration of percussion sounds ranged from 4.40–5.33 ms;
percussion sound values of periodontal patients were of longer duration than those of healthy subjects;
a close correlation between duration and other individual parameters was found in all upper teeth, with the exception of molars.
An in vitro evaluation of a prototype CFRC prefabricated post developed for the restoration of pulpless teeth
Authors: KING P. A. , SETCHELL D. J. 
Published: June 2007

SummaryCarbon fibre reinforced carbon (CFRC) in the form of a prefabricated post* has recently been developed and is theoretically acceptable for consideration in an endodontic post‐retained crown system. This study compared four different types of postcore system cemented into 40 extracted anterior human teeth. The test groups consisted of CFRC posts cemented with a composite resin luting agent, and used with either a cast gold alloy core (Group B) or a composite resin core (Group C). Two existing post‐core techniques were used as controls for comparison with the CFRC groups. One control was a prefabricated wrought precious alloy post having a cast gold alloy core, and cemented with zinc phosphate cement (Group A). The other was a prefabricated stainless steel post with a composite resin core, and cemented with a composite resin luting agent (Group D). All specimens were restored with a gold alloy crown and tested to failure with an obliquely applied compressive load at 130° in an Instron using a cross‐head speed of 5 cm min−1. The results showed that post‐retained crowns using a prefabricated CFRC post exhibited properties comparable with, and in some cases better than, those of existing prefabricated posts. The mode of failure of specimens restored with a CFRC post was more favourable to the remaining tooth tissue than was that of specimens restored with a metallic post.
The effect of a change in dietary habit upon maze learning ability in rats
Authors: AKIYAMA Y. , SHIKIMORI M. , SATOV A. , MOTEGI K. 
Published: June 2007

SummaryAn experimental psychological study was undertaken to assess the effect of a change in dietary habit upon behavioural development, using as a laboratory animal male Wistar rats maintained on natural foods and a processed food. Forty male Wistar rats were weaned at 21 days of age and divided into two equal groups. Group 1 was fed natural food (pressed wheat, dried fish, peanuts, cabbage and soybeans) and group 2 was fed powdered food. At 68 days of age, the rats were tested in a T‐maze. The results showed that Group 1 excelled with regard to T‐maze learning.
Proximal tooth surface quality and periodontal status
Authors: YUSOF Z. 
Published: June 2007

SummaryThe aim of this study was to determine the periodontal status in relation to the quality of the adjacent proximal tooth surface. The gingival index (GI) and probable pocket depth (PD) were measured in 144 contra‐lateral pairs of sound vs. restored and 95 contra‐lateral pairs of sound vs. carious surfaces in 124 patients. The restorations studied were silver amalgams and tooth‐coloured filling materials, the margins of which were supragingival or level with the gingival margins. The results showed that the GI and PD were greater for both restored and carious tooth surfaces than for the contra‐lateral sound surfaces. When all the teeth were grouped together, the differences in the mean values of GI and PD were statistically significant at the P≤0.05 level. A comparison between restored and carious (non‐paired) tooth surfaces revealed higher mean values of GI and PD for the latter, which were highly significant at the P<0.001 level. Thus the present study shows that proximal tooth surface quality influences the health status of the adjacent periodontium.
Condylar movements in clicking joints before and after arthrography
Authors: ROHRER F.A. , PALLA S. , ENGELKE W. 
Published: June 2007

SummaryThe aim of this study was to investigate whether anaesthesia and contrast medium injection alter the biomechanics of the TMJ, thus influencing the arthrographic diagnosis in patients with anterior disc displacement with reduction.Opening and closing movements were recorded in nine patients by means of an opto‐electronic motion recorder (Jaws 3D) before anaesthesia, after anaesthesia and after arthrography. The system computed the trajectories of a condylar point in the sagittal, frontal and horizontal plane. Data were analysed for changes in the position of the clicks, for the amount of condylar translation and for changes of the trajectories between recording conditions.The results indicated that arthrography had a significant effect on the position of the opening clicks in all nine patients. After injection, the clicks occurred on average 1.6mm later than before injection. This was probably due to the excursive movements required for defusion of the contrast medium in the joint. The other parameters examined were not affected by the joint anaesthesia and the arthrographic procedure. The interventions influenced the shape and the incline of the sagittal condylar movement in three of the nine patients. In conclusion, arthrography altered the joint biomechanics, but not sufficiently to invalidate the arthrographic diagnosis.
Microleakage in three designs of glass ionomer under composite resin restorations
Authors: GORDON M. , WASSERSTEIN A. , GORFIL C. , IMBER S. 
Published: June 2007

SummaryThree Class V cavity configurations with walls above and below the cemento‐enamel junction were compared when ‘sandwich’ technique restorations with glass ionomer and composite resin were used. No dye penetration occurred at the occlusal cavosurface margin when the latter was bevelled and light‐cured Scotchbond was applied to the ethced enamel before restoration with Durafil composite resin. The least dye penetration at the gingival margin was observed when Ketac bond glass ionomer covered the entire non‐bevelled wall. No configuration entirely eliminated dye penetration at the gingival margin.
Management and subsequent 13‐year progress of a mandibular fracture with malocclusion in a child – case report
Authors: TAMARI K. , SHIMIZU K. , MURAKAMI T. , TAKAHAMA Y. , YOKOTA S. 
Published: June 2007

SummaryUnder acute conditions, maxillofacial injuries may be treated without the opportunity for an assessment of occlusal irregularities, even when there are mandibular fractures, because life‐threatening injuries have priority over occlusion. Consequently, mandibular fractures may result in post‐trauma malocclusion and facial deformity.The case history reported is of amale patient who had been involved in a traffic accident in childhood and suffered mandibular fractures. The initial incomplete man‐ agement resulted in persistent deformation of the mandible, disturbance of dental occlusion and difficulty in mastication. These irregularities were corrected during childhood by non‐operative orthodontic treatment.When the patient reached adulthood, some permanent teeth were malformed because the fractures had damaged some tooth germs. However, the permanent dentition in general was almost normal as a result of the corrected primary dentition. Although the alveolar deformity due to the injury remained, the mandibular base was satisfactorily remodelled.The case reported supports the view that early restoration of normal dental occlusion before the eruption of permanent teeth contributes to the establishment of good functional dental occlusion of the permanent teeth.
The prevalence of craniomandibular disorders in completely edentulous denture‐wearing subjects
Authors: MERCADO M.D.F. , FAULKNER K.D.B. 
Published: June 2007

SummaryA total of 201 completely edentulous subjects taken consecutively from the waiting list of the Royal Dental Hospital of Melbourne were examined. Data were obtained from the dental history and anamnestic and clinical examinations. Analysis revealed that parafunctional habits were prevalent among complete denture wearers, and that elderly complete denture wearers potentially present more signs and symptoms of craniomandibular disorders than do younger subjects.
Comparison of amalgam behaviour under static and cyclic sub‐modulus of rupture loading
Authors: GERZINA T.M. , WING G. 
Published: June 2007

SummaryThe behaviour of amalgam beam specimens subjected to a sub‐modulus of rupture load at 37°C was compared in static and cyclic modes. Testing was performed using identical equipment, with cyclic testing conducted by intermittent load application for both tests. The specimens tested exhibited varying degrees of deformation and times to fracture in both tests. The mode of load application, either cyclic or static, did not appear to have a significant effect on the degree of amalgam deformation or time to fracture. The most important factors relating to deformation are time of total load application, creep of the specific amalgam and temperature of testing.
Magnesium sulphate as a new desenstizing agent
Authors: GUO‐HUA LIU , MORIMOTO M. 
Published: June 2007

SummaryVarious desensitizing agents have been used in clinics to solve the problem of dentinal hypersensitivity (DH), but none of them has been shown to be consistently effective. We here introduce a new type of desensitizing agent, i.e. 4% magnesium sulphate with iontophoresis at 2mA for 3 min. These optimal conditions were determined by animal experiments, while only a minor effect on dentinal issues was observed within 4 weeks after the treatment. When this desenistizing agent was used to treat DH, the cure rate of 62.4% remained steady within the 25‐week observation period, while some effect was achieved in all the subjects who participated in the study.
Effects of phosphoric acid and tannic acid on dentine collagen
Authors: OKAMOTO Y. , HEELEY J.D. , DOGON I.L. , SHINTANI H. 
Published: June 2007

SummaryWe examined the effects of phosphoric acid, the most common enamel etchant in composite resin therapy, on dentine collagen. Dentine collagen pretreated with 7 M phosphoric acid was shown to be more susceptible to trypsin digestion than untreated collagen. This susceptibility increased with increasing duration of exposure to the acid. The results indicate that phosphoric acid induces a conformational change in dentine collagen (denaturation or perturbation) similar to that observed with 0.39 M HCI, which has a similar pH value (0.65). However, phosphoric acid‐pretreated dentine collagen, when treated with tannic acid for 2 h, became as resistant to tryptic digestion as intact dentine collagen. The present results suggest that tannic acid may work as a dentine conditioner in composite resin therapy, in view of the fact that phosphoric acid etchant is applied, either deliberately or inadvertently, to dentine, and would thus induce denaturation or perturbation of collagen.
Palpation as a method for evaluating occlusal discrepancies
Authors: ITO Y. , RUCKER L.M. , HASHIMOTO K. , TAKEHANA S. 
Published: June 2007

SummaryIn this study, 30 dentists were surveyed about their methods of palpating teeth for the evaluation of premature contacts. Thirty‐eight dentists were then tested to determine their ability to discriminate degrees of prematurity using each of two different methods of palpation. The degree of digital pressure used by each dentist during palpation was also measured. The majority of dentists chose the same method for palpation: a single forefinger overlaying the facial surfaces of the central incisors being evaluated. In the discrimination test, the majority of dentists were able to identify reliably occlusal interference of ≥50 μm regardless of the palpation method used.
Prevalence of craniomandibular disorders in adults of Ilala District, Dar‐es‐Salaam, Tanzania
Authors: MAZENGO M. C. , KIRVESKARI P. 
Published: June 2007

SummaryThe prevalence and distribution of signs and symptoms of craniomandibular disorders (CMD) were studied in a random sample of 100 adult Tanzanians. The associations between subjective and objective findings were analysed. Signs and symptoms of CMD were assessed by interview and clinical examination. Twenty‐six per cent of subjects reported at least one symptom, and in 40% at least one clinical sign was present. No significant differences were observed between the sexes. Tenderness of the lateral pterygoid area and crepitation of the temporomandibular joint increased significantly with age. Several significant associations between subjective and objective findings were observed. The distribution of the signs and symptoms of CMD in Tanzanians was not dissimilar to that observed in the developed countries. The prevalence was not high by comparison, but sufficient to lend credence to the general view that CMD is a universal problem.
Dentine hypersensitivity – the effect of toothbrushing and dietary compounds on dentine in vitro: an SEM study
Authors: ABSI E.G. , ADDY M. , ADAMS D. 
Published: June 2007

SummaryDentine hypersensitivity occurs when dentinal tubules are open on the dentine surface and patent to a vital pulp. There has been limited interest in the aetiology of dentine hypersensitivity. In particular, little is known about agents that remove the dentine smear layer to expose tubules. Toothbrushing certainly may expose dentine, but whether a toothbrush per se has the effect of opening tubules has not been established. The aim of this study in vitro was to determine whether a toothbrush could remove or create a smear layer. In addition, the combined effects of toothbrushing with dietary fluids on dentine was assessed. Toothbrushing was observed, by scanning electron microscopy, both to remove and to recreate a smear layer on dentine specimens. However, the processes took a considerable time, and under conditions of normal toothbrushing it is unlikely that the latter plays a direct aetiological role in opening tubules. Indeed, together with toothpaste it is more likely that brushing has a therapeutic action by mechanically forming a smear layer. Conversely, and importantly, toothbrushing in the presence of dietary acids enhanced smear layer removal. This finding raises the question of whether the dental profession should be advising that teeth be brushed before meals rather than after, as is often the case.
The antimicrobial effect of an iron‐binding agent on Streptococcus mutans
Authors: BAPNA M.S. , MUKHERJEE S. , MURPHY R. 
Published: June 2007

SummaryThe antimicrobial activity of 2,2′‐bipyridine, an iron‐binding agent, was investigated by incorporating this agent into Scotchbond® dental adhesive resin. The growth of Streptococcus mutans on the surface of resin, media and culture vessel was determined by optical density measurements. It was observed that 2,2′‐bipyridene exhibited excellent antimicrobial properties.
Bond strength and rupture properties of some soft denture liners
Authors: SINOBAD D. , MURPHY W.M. , HUGGETT R. , BROOKS S. 
Published: June 2007

SummaryThe bond strength and rupture properties of three soft acrylic liners (Coe‐Soft, Coe Super‐Soft and Vertex Soft) and two silicone liners (Molloplast‐B and Flexibase) were tested immediately after processing and following immersion in water at 37°C for 7 and 90 days. The bond test gave variable results, as some materials partly peeled and then stretched until rupture occurred. After saturation the acrylic liners exhibited an increase in tear resistance, whilst silicone materials deteriorated, in the case of Flexibase to approximately 25% of its original value. Vertex Soft was the exception, as tear resistance decreased as water sorption increased. Scanning electron microscopy revealed indefinite demarcation between soft acrylic resins and hard denture base, which was not altered after saturation in water. On the other hand, the interface between denture base and silicone liners was clearly visible before and after saturation. The results indicated that denture soft liners had variable water sorption values depending on their basic structure, and some properties changed after immersion in water, a finding that is of relevance to prosthodontic practice.
The relationship of occlusion, parafunctional habits and recent life events to mandibular dysfunction in a non‐patient population
Authors: SCHIFFMAN E. L. , FRICTON J. R. , HALEY D. 
Published: June 2007

SummaryThis study investigated the association between occlusion, oral habits and stress relative to the level of mandibular dysfunction in the total population and in specific diagnostic subgroups (normal, joint disorder, muscle disorder and joint/muscle disorder). A total of 269 nursing students were given a questionnaire and examination. The questionnaire included items to calculate an oral habit index and a social readjustment rating scale. The examination included items to calculate an occlusal index, two craniomandibular indices and a diagnostic criteria for specific subgroups. In the total population there was a positive association between mandibular dysfunction and three postulated risk factors. The total population was then divided into diagnostic subgroups. There was a positive association between the degree of mandibular dysfunction and parafunctional habits for normals, muscle disorders and joint/muscle disorders. There was a positive association between mandibular dysfunction and occlusion for normals only. Finally there was a positive association between mandibular dysfunction and stress for muscle disorders only. The results suggest that associations between postulated aetiologic factors and mandibular dysfunction vary depending on whether the subjects have a muscle and/or joint disorder. Since all associations were weak, other possible risk factors need to be investigated.
A preliminary study of manducatory behaviour influenced by stress and dental occlusion
Authors: WESTPHAL A. , DIVRY M. , LEY I. 
Published: June 2007

SummaryStress and dental occlusion often are incriminated as causes of dysfunction of the manducatory system. How and in what degree these two factors came through has not yet been clearly worked out. Our study is carried out on a group of rats presenting one or both of these two factors and we proposed to examine the duration and frequency of some components of their behaviour – intake of solid food and grooming, to detect some possible perturbations on manducatory behaviour caused by stress and/or occlusal interference.Our study shows that stress induced by emotion or occlusal interference will change the microstructure of behaviour rather than the global component in itself. This implies that we must find a clear definition of the different types of microstructure to find out which ones are changed by the two incriminating factors and which part of the behaviour component will remain stable.
Discrimination of clenches at varied jaw positions using autoregressive model coefficients of myoelectrical activities of anterior temporal and masseter muscles
Authors: MAO Y. , SHI C.‐S. , GUO T. W. 
Published: June 2007

SummaryDuring 10% maximum clenching at intercuspal, protruded, retruded contact and lateral positions, the surface electromyograms (EMG) of bilateral anterior temporal and masseter muscles of 20 normal subjects with intact natural dentitions were recorded. The autoregressive (AR) model of the sampled EMG was then built and the obtained coefficients of the AR model were accepted as featured parameters of the EMG. Finally Bayes' stepwise discriminant analysis was used for establishing discriminant functions of estimating low level clenches at varied jaw positions. It was found that total conformation rates of internal and external sample substitution (15 and 5 subjects) were 82.67% and 78% respectively; the discriminant effect between intercuspal and retruded contact position was not up to predicted standard. The results indicate that AR model coefficients may describe the characteristics of surface EMG of masticatory muscles and easily be used in multiple statistical analysis, from which the classification and diagnosis may be taken.
Effect of mechanical pressure on the blood flow in human palatal mucosa measured by temperature controlled thermoelectrical method
Authors: YOSHIDA N. , MINAGI S. , SATO T. , KADOYA S. , MATSUNAGA T. 
Published: June 2007

SummaryMucosal blood flow in the human palate was measured by a temperature controlled thermoelectrical method based on the thermal conductivity of mucosal tissue using a blood flow monitor and a non‐invasive surface probe.The effect of mechanical pressure on the palatal mucosal tissue was studied. Mechanical pressure (2.5, 5.0, 7.5, 10.0 or 15.0g mm−2) to the mucosal surface was exerted circumferentially around the surface probe. In five out of seven subjects, the blood flow showed a tendency to be almost constant under the mechanical pressures which are 10.0g mm−2 or higher. The effect of the duration of the pressure (10.0g mm−2) exertion on the blood flow was also investigated and it was revealed that the blood flow tended to be constant after 60s in every subject. In the present study, it was also demonstrated that the temperature controlled thermoelectrical method is appropriate for studying the blood flow dynamics in oral mucosa.
Observation of proportionality of myoelectrical activity of anterior temporalis to masseter muscle during clenching at varied jaw positions
Authors: SHI C.‐S. , AN Y. 
Published: June 2007

SummaryTwelve healthy subjects with an intact permanent dentition and normal occlusion were selected for sampling of myoelectrical activity of their left and right anterior temporal and masseter muscles during habitual clenching level in varied positions. The proportionality of normalized myoelectrical potentials of anterior temporal muscle to masseter muscle at ICP and RCP was greater than one, while the proportionality at PP was less than one. In the lateral position, the proportionality on the working side was approximately equal to that at RCP, while the proportionality on the non‐working side was similar to that at PP. These results suggest that temporal muscle contraction can bring the mandible upward and backward whilst the masseter muscle can elevate the mandible upward and forward.
Hemifacial microsomia and hypodontia: a case report
Authors: ALKUMARU H. N. , CÖLOK G. 
Published: June 2007

SummaryA 6‐year‐old girl with hemifacial microsomia was examined. Abnormalities found were: severely malformed pinna of the right car, right malar hypoplasia and unilateral mandibular hypoplasia. Dental examination revealce normal intraoral soft tissues with all deciduous teeth present. Radiographic examination disclosed that the maxillary and mandibular right and kleft second premolars were not devcloping. The mandibular ramus was short in leanth and the mandibular condyle had not developed on the right. The patient had no renal, cardiac or skeletal anomalies and her hearing was normal. No previous publications have been located whchreport the association of hypodontia and hemifacial microsamia.