bluuebunny/crossref_metadata_2025_split huggingface dataset:
Personality and anxiety in temporomandibular joint syndrome patients
Authors: SOUTHWELL J. , DEARY I.J. , GEISSLER P. 
Published: June 2007

SummaryMuch research has suggested that anxiety is involved in the temporomandibular joint syndrome (TMJ), but it is not clear whether it is a cause or a consequence of the disorder. The present study attempts to resolve this issue. Thirty‐two patients suffering from temporomandibular joint syndrome and 32 sex‐ and age‐matched dental clinic controls completed the Spielberger State‐Trait Anxiety Inventory, the Eysenck Personality Questionnaire and a standardized inventory of bodily symptomatology. TMJ patients scored significantly higher on Eysenck's neuroticism and introversion scales (both P < 0.05) and had higher trait anxiety scores (P < 0.005) when compared with controls. These results suggest that TMJ patients have personalities that are vulnerable to life stresses, but that they are not more anxious than controls at any given time. Such a personality profile is similar to that found in other ‘functional’ syndrome patient groups, such as individuals with globus pharyngis. We suggest that certain stress prone personalities express anxiety in the form of a predictable set of physical syndromes which may be subject to changes with time.
Number of remaining teeth and rehabilitation with removable dentures in psoriatics
Authors: KÖNÖNEN M. , MURTOMAA H. 
Published: June 2007

SummaryThe aim of this investigation was to study associations between the state of dentition and socio‐medical aspects in psoriatics.It was found that the number of remaining teeth in subjects under 65 years of age was higher in psoriatics with skin symptoms (P‐group) than in psoriatics with skin and joint symptoms (PA‐group) (P<0.01), this rate being higher than that found among the general population in Finland. In younger subjects, women in the P‐group wore removable dentures more frequently than did women in the PA‐group (P<0.05), whereas among older subjects men in the PA‐group wore removable dentures more frequently than did men in the P‐group (P<0.001). In the log‐linear model that was applied, more advanced age, lower level of education and infrequent dental visits were associated with a low number of remaining teeth in both the P‐group and the PA‐group. A poor general state of health in the P‐group and a high number of teeth, indicating that there is an association between severity of general disease and dental health status.
Custom overdenture retainer
Authors: NEMCOVSKY C.E. , FITZIG S. , GROSS M. 
Published: June 2007

SummaryA simple technique for fabricating stud overdenture retainers in the form of custom attachment castings with teflon retention discs has been described. This system allows for selective placement of the retention sphere on the root surface and control of retention through the size of the retention sphere. Using transfer location projections, exact transfer of the castings to the working model is possible. When necessary, the teflon discs may easily be replaced at the chairside.
Further studies of some masticatory characteristics of bruxism
Authors: FAULKNER K.D.B. 
Published: June 2007

SummaryQuantitative analysis of a time dependent factor of jaw movement has shown there to be a significant difference in the muscle physiology of non‐bruxist and bruxist subjects.Because bruxism can be difficult to detect in some patients, these results indicate that further development of the technique of jaw movement analysis might be useful as a diagnostic tool. They also point to the value of further study into the possible detection of ‘potential’ bruxists, thus allowing the development of a preventive aspect of bruxism.
Cu‐Ti, Co‐Ti and Ni‐Ti systems: corrosion and microhardness
Authors: CHERN LIN J.‐H. , MOSER J.B. , TAIRA M. , GREENER E.H. 
Published: June 2007

SummaryTitanium alloys of 10 wt % ‐72 wt % Cu, 10 wt % ‐80 wt % Co and 20 wt % ‐84 wt% Ni were investigated. Ingots were fabricated in a vacuum/argon tungsten arc furnace. The surfaces of the alloys were examined by optical microscopy and SEM/EDS, and the Knoop hardness values of the alloys were measured. The corrosion resistance of the alloys was determined by a potentiodynamic polarization technique in buffered Ringer's solution. When a threshold composition of 30 wt % alloy was reached, a large decrease in corrosion resistance was found to occur. Knoop hardness measurements showed that similar hardness values of approximately 300 KHN can be obtained in all systems with lower alloy content. These values are similar to those obtained with a commercial dental titanium alloy.
Sensitivity to ambient light of visible light‐cured composites
Authors: DIONYSOPOULOS P. , WATTS D. C. 
Published: June 2007

SummaryFourteen representative visible light‐cured composite materials, including a total of 29 shades, have been examined for sensitivity to ambient light. The assessment was based upon a procedure recommended in an International Standard (ISO/DIS 4049). All but four of the 29 formulations exceeded the critical working time of 60 s when exposed to ambient illumination of 20 klx. These four composite resins exhibited working times greater than 60 s under 10 klx illumination, and the maximum working time observed at 10 klx was 227 s. These data confirm the finite working time of light‐cured resins under clinical lighting conditions.
Long‐term use of dentine adhesive as an interfacial sealer under Class II amalgam restorations
Authors: BEN‐AMAR A. , LIBERMAN R. , JUDES H. , NORDENBERG D. 
Published: June 2007

SummaryAn in vitro study was carried out to evaluate the long‐term sealing properties of a light‐cured dentine adhesive in Class II amalgam restorations. The restorations were subjected to repeated vertical occlusal loads and a number of thermocycling procedures. The results demonstrated significant advantages of using a dentine adhesive as an interfacial sealer in order to reduce microleakage, compared to a conventional Copal varnish.
A comparative study between three ethnic groups to derive some standards for maxillary arch dimensions
Authors: DIWAN R. , ELAHI J. M. 
Published: June 2007

SummaryA sample of 91 adult Philippinos, 45 males and 46 females, were selected for maxillary arch measurements. The intercanine width (C‐C), intermolar width (M‐M), molar incisor (M‐I) and molar canine (M‐C) length were measured. The measurements were compared to previous studies of maxillary arch dimensions for adult male and female Egyptians and Saudi Arabians. The results showed wider (M‐M) measurements for the Egyptians than for the Philippinos, who also showed wider (C‐C) arch dimensions than the Saudi Arabians.
Method for identification and classification of single motor unit potentials in diagnostic electromyography
Authors: WIDMALM S.‐E. , ASH MAJOR M. 
Published: June 2007

SummaryIt is important to have an objective method for recording jaw muscle capacity such as EMG before, during and after treatment of muscle dysfunction and also for oral rehabilitation with dentures, implants or other types of restorations. Because measurements of motor unit potentials (MUPs) are needed in several areas of EMG analysis, algorithms have been developed in our laboratory for use in a small computer‐aided system for semi‐automatic detection and pattern recognition of MUPs. Based upon the test recordings it is suggested that a characteristic ‘maximal voltage increase per μs during the spike‐phase’ can be used as a supplement to the more generally used parameter ‘rise‐time’. Examples are given of how the programs can be useful in the study of the functional anatomy of jaw muscles by recording normative values for MUPs and their recruitment patterns.
Wear of composite resin in vitro: a testing machine with rubber plate. Preliminary results
Authors: HENGCHANG X. , VINGERLING P. A. , WENYI L. , GANG Z. , TONG W. 
Published: June 2007

SummaryA new machine was developed to study the wear of dental filling materials in vitro. Four products: amalgam, Adaptic, Clearfil and acrylic resin were tested. Wear was measured quantitatively by weighing the specimen, and the wear pattern was studied qualitatively with a scanning electron microscope (SEM). A comparison was made with materials that were placed in the mouth for a prolonged period. It was found that the in vitro wear pattern was comparable to that found in vivo.
A potential MRI hazard: forces on dental magnet keepers
Authors: GEGAUFF A.G. , LAURELL K.A. , THAVENDRARAJAH A. , ROSENSTIEL S.F. 
Published: June 2007

SummaryThe objective of this study was to determine the forces on dental prosthetic magnet keepers, with a view to assessing the potential for patient injury during magnetic resonance imaging (MRI). Four pre‐formed keepers and one castable keeper alloy were tested. Magnetizations and high field susceptibilities were determined for each of the five specimens using data from a vibrating sample magnetometer. The magnetic field intensity with respect to distance from the main magnet coil was obtained from the manufacturer (1–5 tesla General Electric Signa Imaging System)*. A plot of force versus distance from the main coil and the maximum force at the magnet portal was determined for each specimen. The maximum forces ranged from 0.12–0.24N for the pre‐formed keepers and 3.67 MNm−3 for the castable alloy. It was concluded that the risk of patient injury by displacement is minimal, if the keepers are properly attached to supporting structures.
Electrical potentials of restorations in subjects without oral complaints
Authors: MULLER A.W.J. , VAN LOON L.A.J. , DAVIDSON C.L. 
Published: June 2007

SummaryThe electrical potentials of 183 amalgam and 11 precious metal restorations, and one set of brackets, were measured. None of the 28 subjects had galvanism, leukoplakia, oral lichen planus, or toxic or allergic reactions to restorations. The potentials of the amalgam restorations increased with age, from about −350 mV NHE at 30 days, to about +100 mV NHE after more than 1000 days. In most subjects potential differences of more than 50 mV were present between restorations; this phenomenon is therefore assumed to be common in healthy populations.
Dental cutting behaviour of mica‐based and apatite‐based machinable glass‐ceramics
Authors: TAIRA M. , WAKASA K. , YAMAKI M. , MATSUI A. 
Published: June 2007

SummarySome recently developed industrial ceramics have excellent machinability properties. The objective of this study was to evaluate the dental cutting behaviour of two machinable glass‐ceramics, mica‐containing Macor‐M® and apatite‐ and diopsidecontaining Bioram‐M®, and to compare them with the cutting behaviour of a composite resin typodont tooth enamel and bovine enamel. Weight‐load cutting tests were conducted, using a diamond point driven by an air‐turbine handpiece. While the transverse load applied on the point was varied, the handpiece speed during cutting and the volume of removal upon cutting were measured. In general, an increase in the applied load caused a decrease in cutting speed and an increase in cutting volume. However, the intensity of this trend was found to differ between four workpieces. Cutting Macor‐M® resulted in the second‐most reduced cutting speed and the maximum cutting volume. Cutting Bioram‐M® gave the least reduced cutting speed and the minimum cutting volume. It was suggested that two machinable glass‐ceramics could be employed as typodont teeth. This study may also contribute to the development of new restorative dental ceramic materials, prepared by machining.
Clinical oral test for the assessment of oral symptoms of glossodynia and glossopyrosis
Authors: CEKIĆ‐ARAMBAŠIN A. , VIDAS I. , STIPETIĆ‐MRAVAK M. 
Published: June 2007

SummarySubjective oral symptoms of a burning sensation and pain in the tongue may exist in the absence of any pathological changes in the oral mucosa. Owing to different treatment approaches and the lack of any specific therapy, it appeared potentially useful to identify these subjective symptoms by means of a test for an improved therapy evaluation. In this study, we have attempted to develop a method for the objective assessment of oral symptoms of glossodynia and glossopyrosis, by recording the local temperature. The temperature of the tongue was determined using a DT‐1 electron thermoesthesiometer, that was highly sensitive to temperatures between 36°C and 38°C. Measurements were performed in topographic areas recommended by the World Health Organization in 1980. The study sample consisted of a group of 50 patients with glossopyrosis and glossodynia, without any clinically manifest pathological changes in the oral cavity, who were compared with a group of 50 age‐ and sexmatched subjects free of these oral symptoms and with normal oral mucosa. Statistically significant temperature differences were observed between the patients and the controls, as measured in seven different areas. The lowest temperatures (33°C) were measured in the apex linguae area. The minimum temperature was significantly lower in the study group. Significant differences in temperature were also observed between the sexes. It was concluded that glossodynia and glossopyrosis, both inflammation and diminished circulation without any visible clinical signs, can be diagnosed using the thermoesthesiometry test. Such an objective test allows appropriate therapeutic treatment to be selected for patients with the above‐mentioned symptoms.
The effects of dentine bonding agents on marginal leakage of composite restorations
Authors: SAUNDERS W. P. , GRIEVE A. R. , RUSSELL E. M. , ALANI A. H. 
Published: June 2007

SummaryThe aim of this study was to compare the effects upon marginal leakage of a number of dentine bonding agents: Gluma, Scotchbond, Topaz and an experimental material when used with a posterior composite resin, Occlusin. The results were also compared with composite used without a dentine bonding agent and with a glass ionomer, Chemfil II.Class V cavities with or without a bevelled cavo‐surface margin were prepared in the buccal surfaces of extracted premolar teeth. Following restoration, the teeth were stored for periods of up to 3 months and then thermally cycled. Marginal leakage was subsequently determined using a radioactive isotope containing 45Ca, and an autoradiographic technique. Image analysis was used to determine the total amount of linear leakage for each specimen. The results showed that some leakage occurred for all materials at each time interval. The bevelled design of cavity allowed significantly less leakage than the non‐bevelled type. The use of dentine bonding agents did not improve the marginal seal of the composite restorations, and the glass ionomer restorations showed significantly less leakage than the composite resin and dentine bonding agent combinations.
Studies on fracture toughness of dental ceramics
Authors: TAIRA M. , NOMURA Y. , WAKASA K. , YAMAKI M. , MATSUI A. 
Published: June 2007

SummaryOne important mechanical property of dental ceramics is fracture toughness, KIC, which represents the serviceability in the oral cavity, such as the resistance to marginal fracture. KIC values of several dental ceramics, natural tooth enamel and industrial ceramics were examined by use of the indentation microfracture (IM) method. This technique was based on the series of radial cracks emanating from the corners of the Vickers indentation. It was observed that appropriate load levels should be selected on each specimen to induce radial/median cracks. For feldspatic dental porcelains, larger loads of 10, 20 and 30 kg were needed to determine their KIC values in the range 1.5–2.1 MN‐rn−3/2. For natural tooth enamel and a new apatite‐based castable glass‐ceramic, a smaller force of 1 kg was sufficient to decide the respective KIC values of about 0.9 and 1.8 MN‐m−3/2. The KIC values of most dental ceramics examined were slightly higher than that of soda lime glass, but less than one‐third that of zirconia. It was confirmed that the IM method is simple and cost‐effective for evaluation of KIC of dental ceramics.
Mandibular movement and velocity in relation to state of dentition and age
Authors: KARLSSON S. , PERSSON M. , CARLSSON G. E. 
Published: June 2007

SummaryParameters of mastication, such as mandibular displacement, velocity and chewing cycle duration, were investigated in relation to age and rehabilitation with complete dentures. Two groups of elderly subjects (mean age 80 years), one with natural dentition and the other with complete dentures, and one group of young dentate adults (mean age 26 years) participated. Three‐dimensional records of masticatory mandibular movements were obtained using the Selspot movement analysis system.There were no differences in the duration of the total or individual components of a chewing cycle, except for the closing phase, which was significantly longer in the complete denture group. Mandibular closing velocity was significantly lower in the two groups of elderly subjects than in the group of young adults. There was a high degree of inter‐individual variation in mandibular displacement in all groups, but the mean vertical amplitude was smaller in the elderly groups compared to the group of young adults. For many of the parameters the variation was significantly greater in the groups of elderly subjects than in the younger group. Ageing thus appeared to have a more important effect than the state of the dentition on the parameters studied.
Replication of human occlusal tooth attrition surfaces for scanning electron microscopic study
Authors: AKPATA E. S. , WINTER P. J. 
Published: June 2007

SummarySilicone negative replicas of dentine islands exposed by occlusal attrition were examined on extracted human teeth using the scanning electron microscope. Because the details of the dentinal tubules were reproducible on the silicone impression, the replication technique was applied in vivo to occlusal attrition to demonstrate patent dentinal tubules in cases with symptomatic exposed dentine islands.Using this replication technique, it should be possible to monitor the effect of the therapeutic management of symptomatic tooth attrition on dentinal tubule closure.
Dental amalgams subjected to sub‐fracture stresses at 37°C
Authors: GERZINA T.M. , WING G. 
Published: June 2007

SummaryAmalgam beam specimens were subjected to sub‐modulus of rupture loads at 37°C. The specimens tested underwent varying degrees of deformation and ultimate fracture determined by the degree of specimen bend and time to fracture. The property most closely related to the sub‐fracture loading behaviour was creep, particularly the 72‐h determination of this property. Time and temperature of testing are also significant factors.The present study indicates the importance of the use of 37°C testing in low‐load stressing of dental amalgam. The study has confirmed the nature of failure of amalgam in relation to its rheological properties at the temperature at which amalgam functions clinically.
Parotid salivary flow rates in two patients during immediate denture treatment
Authors: JENSEN J.C.L. , BRODIN P. , ØRSTAVIK J. 
Published: June 2007

SummaryParotid salivary flow rates in response to chewing or citric acid stimulation were studied in two patients who had their last maxillary teeth extracted and immediately replaced with complete dentures. The patients were monitored 6 months from the last week before extraction.Parotid salivary flow rate in response to chewing was increased after insertion of the denture. For one of the patients a particularly high output from the parotid gland was found 2 weeks after treatment. Throughout the experiment, parotid salivary flow was higher on the chewing side than on the contralateral side. At the end of the experimental period the dentures were relined. Salivary flow measured immediately after relining was lower than prior to this procedure.An increased salivary response was also observed during citric acid stimulation after transition from the dentate to the denture wearing state. This increase was more marked if the patients had their dentures in situ when the gustatory provocations were performed.It is concluded that parotid salivation increases during masticatory and gustatory stimulation in patients subjected to total extraction and immediate complete denture treatment, and that the presence of a complete denture per se appears to act as an additional mechanical stimulus in the salivary reflexes.
Changes in compressive strength of glass ionomer restorative materials with respect to time periods of 24 h to 4 months
Authors: WILLIAMS J.A. , BILLINGTON R.W. 
Published: June 2007

SummaryThis study investigated whether long‐term changes occur in the compressive strength of a number of glass ionomer restorative materials, in view of the fact that little information is available from the manufacturers, and any variations with time might affect suitability for clinical use.It was found that, over the period of 24 h to 4 months, some materials, namely those based on polyacrylic acid, maintained or even showed a slight increase in their strength, whereas others based on copolymers of acrylic acid first increased in strength, but thereafter showed deterioration. In one case the strength decreased by nearly 50% compared to that at 24 h.
The relationship between the isotonic mechanical power in jaw‐opening and jaw‐closing muscles in man
Authors: WATANABE K. , SHIMIZU K. , NAKATA S. , WATANABE M. 
Published: June 2007

SummaryThe relationship between isotonic jaw‐opening and jaw‐closing muscle function was studied using a newly developed apparatus which enables load and velocity to be detected simultaneously. The following results were obtained from 17 male adults(age range 22–23 years) without any occlusal dysfunction.(i) The force‐velocity relationship in jaw‐opening and jaw‐closing muscles was represented by a hyperbolic curve, which fitted well with Hill's equation.(ii) The theoretical maximum force obtained by extrapolation from regression was 32.55±4.98 kg for jaw opening and 35.74±4.52 kg for jaw closing.(iii) The theoretical maximum velocity obtained by extrapolation from regression was 456.70±183.27 mm s−1 for jaw opening and 372.77±141.67 mm s−1 for jaw closing.(iv) The maximum mechanical power (Pmax) calculated from the product of the force and velocity was 772.20±182.65 kg.mm s−1 for jaw opening and 708.68±128.14 kg.mm s−1 for jaw closing.(v) The Pmax exerted by individual subjects was approximately 12–34% of the maximum possible force (Fmax) calculated from the force and velocity, in both jaw opening and jaw closing.There were no statistically significant differences between jaw opening and jaw closing with regard to any isotonic muscle functions. In other words, the results of this study strongly indicated a substantial balance between isotonic jaw‐opening and jaw‐closing muscle function in the subjects who were investigated.
Power spectral analysis of occlusal sounds of natural dentition subjects
Authors: CHONG‐SHAN SHI , GUAN OUYANG , TIAN‐WEN GUO 
Published: June 2007

SummaryFifteen subjects with complete natural dentitions were selected for investigation of their occlusal sounds on the left and right sides by means of power spectral analysis. It was found that the occlusal sounds consisted of various frequency componets. Their mean power frequencies (MPF) and frequences at 10, 20, 50, 80 and 90% of cumulative powre (F10, F20, F50, F80, F90) on the left and right sides were almost identical (P<0.05). The correlation coefficients between MPF and F50, MPF and F50 with the others were high. The results indicate that F20, MPF or F50 and F80 may be used as indices to describe the power spectral shape, and that power spectral analysis of occlusal sounds may be used as a contribution to diagnosis of occlusal conditions.