bluuebunny/crossref_metadata_2025_split huggingface dataset:
First experiences with resin‐bonded bridges and splints—a cross‐sectional retrospective study, part II
Authors: MARINELLO C. P. , KERSCHBAUM Th. , HEINENBERG B. , HINZ R. , PETERS S. , PFEIFFER P. , REPPEL P. D. , SCHWICKERATH H. 
Published: June 2007

SummaryThis second report establishes that the success of treatment with resin‐bonded bridges was dependent upon many factors. Factors controlled by the clinician, such as case selection and treatment planning greatly influence the clinical success. It was possible to show that framework preparation and the amount of available enamel were significant factors, whereas isolation technique, type of retention mechanism and type of adhesive used were of less importance. Longitudinal studies are needed to confirm these observations.Seventeen clinicians placed 496 resin‐bonded bridges and splints with different retention mechanisms and bonding agents. These reconstructions were examined in regard to the failure rate and in regard to reattachment problems. Ninety‐seven per cent of the bridges and 90% of the splints were still in place after 1 year. For bridges and splints a 90% success rate was ascertained after 2 years.
Force–displacement properties of a modified cross‐linked silicone compared with facial tissues
Authors: FARAH J. W. , ROBINSON J. C. , HOOD J. A. A. , KORAN A. , CRAIG R. G. 
Published: June 2007

SummaryA dimethyl siloxane triacetoxy terminated silane, Type A adhesive, was modified with the base component of a medium grade polydimethyl siloxane with vinyl groups, MDX 4–4210, to produce a more pliable maxillofacial prosthesis. Force–displacement curves of various ratios of Type A adhesive/MDX 4‐4210 were determined and compared with force–displacement curves obtained from human subjects. Within the force range of 0.4 to 1.2 N, the force–displacement slopes obtained on human subjects compared favourably with some of the Type A adhesive/ MDX 4‐4210 test specimens. The force–displacement slopes for the elastomers and humans were not in agreement for forces below 0.4 N.
The use of an electronic thermometer in intraoral temperature measurement
Authors: HARUN Z. , STAFFORD G. D. , HUGGETT R. 
Published: June 2007

SummaryThe applicability of an electronic thermometer CRAFTEMP® in taking intraoral temperatures was determined. Sublingal temperatures in ten young subjects with complete natural dentitions, and the temperatures at the denture base–mucosa interface and on the polished surface of both maxillary and mandibular complete dentures in ten elderly patients were measured. The results showed that there was a temperature difference between the polished surface of the maxillary denture and the denture base–mucosa interface. This was statistically significant in the female but not in the male subjects. No temperature difference could be demonstrated with any of the mandibular dentures. The CRAFTEMP® was found to be a convenient and reliable method for intraoral temperature measurement.
Fixed restorations produced by commercial dental laboratories in Vancouver and Geneva
Authors: MACENTEE M. I. , BELSER U. C. 
Published: June 2007

SummaryA survey of commercial dental laboratories in Geneva and Vancouver has been carried out using both questionnaires and telephone enquiries. It was concerned with the types of fixed prostheses constructed and the impact of recent technical developments.The results of the study revealed that cosmetic factors played a major role in deciding the use of new techniques. Porcelain was used on the occlusal surface of most restorations and metal margins were preferred on PFM crowns. Precious and base alloys were used frequently to cast PFM protheses in Vancouver, whereas semi‐precious alloys were favoured in Geneva. Most of the laboratories used precious alloys for all‐metal restorations.
Oxidation of a gold‐palladium PFM alloy
Authors: VRIJHOEF M. M. A. , VAN DER ZEL J. M. 
Published: June 2007

SummaryIn this study, the influence of oxygen pressure, as well as oxidation time and temperature, on the oxide formation of a gold‐palladium‐indium‐gallium alloy was investigated. After oxidation (vacuum/air, 1–10 min, 940–1020°C) the oxides were removed selectively by means of leaching in 37% hydrochloric acid. Concentrations of the metallic parts of the oxide layers were determined by means of an emission spectrometer. The composition of the oxide layer was computed on the basis of these measurements.Palladium oxide was not found. The formation of In2O3 and Ga2O3 was detected. The oxidation time did not influence the composition of the oxide layer. A higher oxidation temperature gave a slightly greater In2O3 concentration. Oxidation in vacuum resulted in a much higher Ga2O3 content. Under all conditions gallium oxidized preferentially.
The subjective experience of mastication in subjects with shortened dental arches
Authors: AUKES J. N. S. C. , KÄYSER A. F. , FELLING A. J. A. 
Published: June 2007

SummaryIn this study the perception of chewing is investigated in forty‐three subjects with a shortened dental arch (SDA) by means of an interview. A group of fifty‐four subjects with a complete dentition was used as a control group. The aim was: (i) do subjects with a SDA have a higher risk of chewing problems, and (ii) do they have different food perception and food selection leading to change in their diet?The results show that for subjects with a SDA the chewing function, food perception, food selection and actual food consumption are hindered within an acceptable degree.
Electromyographic biofeedback and sustained masseter muscle contraction in man
Authors: WATKINSON A. C. 
Published: June 2007

SummaryTwenty‐two human subjects performed sustained voluntary contractions of the mandibular elevator muscles firstly without and secondly with visual biofeedback. The level of electromyographic activity of the masseter muscle during the second clench exceeded that during the first clench by a mean of 36%. This differential indicates the ability of the subjects to override the central factors which normally limit muscle activity during a fatiguing contraction.
Prevalence of signs and symptoms of mandibular dysfunction among adults aged 25, 35, 50 and 65 years in Ostrobothnia, Finland
Authors: TERVONEN T. , KNUUTTILA M. 
Published: June 2007

SummaryThe prevalence of objective signs and subjectively perceived symptoms of mandibular dysfunction were studied in a sample comprising 1600 subjects, 400 each aged 25, 35, 50 and 65 years. Eighty per cent of the subjects were examined clinically. The prevalence figures were higher among the females than among the males, and a slight tendency for higher frequencies of clinical signs was observed with increasing age. In view of the severity of clinical signs preference should be given for a total of 27% of the subjects when considering the need of treatment. The number of remaining teeth in subjects with natural teeth and no additional removable dentures had no marked influence on the prevalence of mandibular dysfunction, but subjects with complete dentures had signs and symptoms of dysfunction more often than those with natural dentition. The sex and age differences can partly be explained by the higher frequency of complete dentures in females than in males and in the older age groups.
The effects of muscle fatigue on the silent period of the masticatory muscles
Authors: NAGASAWA T. , TAMURA H. , TSURU H. 
Published: June 2007

SummaryThirteen healthy adults performed sustained clenching at 50% maximum clenching level judged electromyographically. Electromyograms were recorded from both anterior temporal and masseter muscles during clenching and the silent period latency and duration were measured. As the result of muscle fatigue, the silent period latency significantly decreased, whilst the duration significantly increased up to 3 min from the beginning of clenching.
Factors influencing the bond strength between glass polyalkenoate (ionomer) cements and dentine
Authors: WALLS A. W. G. , McCABE J. F. , MURRAY J. J. 
Published: June 2007

SummaryA series of investigations have been performed to study some factors influencing the tensile bond strength of glass polyalkenoate cements to dentine. The measured bond strength was affected by the method of storage of the teeth prior to testing, the nature of the dentine and the type of cement used for the tests. The most consistent results for bond strength measurements were obtained with teeth stored in neutral buffered formalin for more than 1 month after extraction, and then stored in distilled water for 4 weeks prior to bond strength determinations. The mean value obtained with this storage regime (1·62 MPa) was not different from that obtained using freshly extracted teeth (1·74 MPa). The bond strength to deciduous dentine (0·72 MPa) was significantly less than that to permanent dentine (1·62 MPa). There were significant differences between the measured bond strengths of the three materials tested, with Ketac‐Fil giving the lowest result (1·62 MPa), then Ketac‐Silver (2·41 MPa), ChemFil II formed the strongest bonds (4·65 MPa).
Quantitative observations on maximum static work efforts and associated pain of the human masseter muscle
Authors: CHRISTENSEN L. V. 
Published: June 2007

SummaryThe single case experimental design was used to study day‐to‐day variations in the onset (PL), tolerance (PT), and intensity (VAS) of masseter muscle pain. Pain was induced by maximum voluntary teeth clenching, with no artificial feedback‐control of the level of isometric activity, and static work efforts were quantified by cumulative electromyography. A continual effort to produce maximum static work, about 40% increase from baseline work, elicited in 30–40s an initial sensation of muscular pain that had an intensity of about 25% of maximum possible score. A further increase in maximum static work effort, about 60% increase from baseline work, caused in about 2min an intolerable increase in the intensity of muscular pain, about 50% of maximum possible score. Whereas PL showed day‐to‐day variation, PT and the ratio PL:PT did not. Intensity (VAS) scores and maximum static work efforts showed no day‐to‐day variations. Onset (PL) and tolerance (PT) showed no linear associations with VAS scores, and VAS scores showed no linear associations with maximum static work efforts; if anything, the latter associations tended to resemble a cubic parabola. Two different central neural processes, not associated with maximum static work efforts in a simple linear manner, might have been instrumental in: (i) the establishment of criteria for onset and tolerance of pain, and (ii) the discrimination of variable levels of pain intensity.
The effect of contact area morphology on operative dental procedures
Authors: LONG T. D. , SMITH B. G. N. 
Published: June 2007

SummaryMeasurements of the contact and embrasure areas of adjacent extracted teeth set in plaster blocks were made before groups of dentists undertook preparations on them. The prepared and adjacent teeth were examined and the findings related back to these measurements.Damage to the adjacent teeth was a common finding with both mesial–occlusal–distal (MOD) and complete crown preparations. There was some evidence that easier access to the contact area reduced the frequency of damage to teeth adjacent to MOD preparations. The taper of complete crown preparations did not conform to commonly recommended designs.This investigation highlights the need for greater consideration of approximal tooth surfaces when undertaking preparations and questions the practicality of achieving traditional features of complete crown preparation design. In teaching, greater emphasis should be placed on clinical reality rather than on theoretical, but unachievable ideals.
Mechanical properties of elastomeric impression materials
Authors: SALEM N. S. , COMBE E. C. , WATTS D. C. 
Published: June 2007

SummaryDental elastomeric impression materials of different consistencies, representing addition and condensation silicones, polysulphides and a polyether, were studied to determine their mechanical properties in terms of tearing energy, tensile properties and modulus determined at high strain rates. Whilst the polysulphides had the greatest resistance to tearing, they were more extensible, had lower moduli of elasticity and lower tensile strengths than the silicones. The polyether resembled the silicones in many respects.
Effects of experimental defects of the articular disc of the temporomandibular joint in rats
Authors: LEKKAS C. , HONEE G. L. J. M. , VAN DEN HOOFF A. 
Published: June 2007

SummaryTriangular defects were made in different locations of the disc in rat temporoman‐dibular joints. After 3 months the following effects were observed. Central defects had become rounded without gross changes in the mandibular head. Peripheral defects were enlarged towards the centre, occasionally accompanied by condylar hyperplasia. Microscopically the cartilagenous covering of the mandibu‐lar head in all operated cases was characterized by thickening, dispersion of cells normally closely packed in the intermediate zone, and the constant appearance of a tear parallel to the surface.
The effect of removable partial dentures on the oral function in shortened dental arches*
Authors: WITTER D. J. , van ELTEREN P. , KÄYSER A. F. , VAN ROSSUM M. J. M. 
Published: June 2007

SummaryIn this study the effect of free‐end removable partial dentures (RPD) on oral function was investigated by comparing subjects with shortened dental arches (SDA, n=55) and a group of subjects with SDA and RPD (n=25). In addition, a group of subjects were selected who had worn an RPD in the past (n=19). All subjects had a remaining natural dentition consisting of an intact front region and three to five occlusal units (OU) in the posterior area.On the whole, subjects with RPD had less natural OU compared with subjects without RPD. However, this is also true for those who had worn an RPD in the past. The oral functions of subjects with SDA did not differ significantly when compared with subjects with SDA and RPD.Significantly more subjects who had an RPD in the past reported a limited mobility of the mandible, an impaired chewing capacity and chewing with the front teeth. They also reported more aesthetic complaints due to missing posterior teeth.It is concluded that within the populations investigated in this study oral function is not evidently improved by the insertion of a free‐end RPD.
Value of EMG analysis of mandibular elevators in open‐close‐clench cycle to diagnosing TMJ disturbance syndrome
Authors: CHONG‐SHAN S. , HUI‐YUN W. 
Published: June 2007

SummaryThe EMGs of the temporal and masseter muscle, in sixty patients with temporomandibular joint disturbance syndrome (TMJDS) and thirty normal controls, were recorded during rhythmical open‐close‐clench cycle movement and before and after occlusal splint therapy. The duration of the muscle contraction before initial tooth contact (DMC), the latent period (LP) and the silent period (SP) of the myoelectrical activity were used as indices for exploring their diagnostic value. In contrast with the controls, DMC, LP and SP lengthened in the patients. The DMC was prolonged in those patients where there were TMJ sounds, the inter‐cuspated position did not coincide with the muscular contact position and there was deviated mandibular movement. An increase of the SP was related to tooth contact on the balancing side. After treatment, the DMC and SP in the patients returned to the level of the controls. It was found that the internal correction rate of Fisher's linear discriminate function established for the DMC and SP of the temporal and masseter muscles was 80.9% and 85.1% respectively. The results show that the DMC and SP of the temporal and masseter muscles have some value in diagnosing muscular dysfunction and discriminating therapeutic effectiveness.
Postural and maximum activity in elevators during mandible pre‐ and post‐occlusal splint treatment of temporomandibular joint disturbance syndrome
Authors: CHONG‐SHAN SHI , HUI‐YUN WANG 
Published: June 2007

SummaryElectromyograms (EMGs) of the temporal and masseter muscles in sixty patients with temporomandibular joint disturbance syndrome (TMJDS) and thirty controls were recorded and integrated on‐line in the postural position and during maximum clenching, before and after occlusal splint therapy. Contrasting with the controls, the myoelectrical activity of the patients was higher in the postural position and lower during maximum clenching, whilst the former in percentage terms increased when compared to the latter. After treatment, the EMG indexes in some patients returned partially, and in others completely, to a normal level. Tenderness in the mandibular elevators, deviated opening and organic change in the TMJ increased the postural myoelectrical activity, in percentage terms, against that of maximum clenching. The myoelectrical activity of the mandibular elevators in the postural position and during maximum clenching was smaller in patients with the occlusal splint than in those without. The results show that the mandibular elevators in the patients with TMJDS were hyperactive and tense, and that the occlusal splint was useful for treating such dysfunction.
Short‐term effect of a stabilization splint on the asymmetry of submaximal masticatory muscle activity
Authors: McCARROLL R. S. , NAEIJE M. , KIM Y. K. , HANSSON T. L. 
Published: June 2007

SummaryTen healthy subjects continuously wore equilibrated maxillary full‐arch stabilization splints in the retruded position for 7 days. The muscular activity balance of the masseter muscles during submaximal isometric clenching at 10% and 50% of the maximum voluntary contraction (MVC) did not change immediately on insertion of the splint, but was improved at the 50% level after 7 days (P<0.05). While the muscular balance of the anterior temporal muscles was not affected, either immediately on splint insertion, or after wearing it for 7 days, temporal muscle activity at 10% of the MVC was greater on the side to which the mandible moved from the retruded contact position (RCP) to the inter‐cuspal position (ICP), both before (P<0.025) and after (P<0.01) wearing the splint. Splint removal after 7 days resulted in increased awareness of interferences in the ICP and increases in masseter muscle asymmetry (10%, P<0.025; 50%, P<0.05) when the electromyograms in the ICP after splint removal were compared with those on the stabilization splint before removal. After wearing the splint, the masseter muscle activity at the 10% level was greater on the side where premature contacts were present in the RCP (P<0.01).The use of masticatory muscle asymmetry indices in the evaluation of splint treatment for craniomandibular dysfunction is indicated since submaximal masticatory muscle activity is related to occlusal stability, premature contacts in the RCP and the direction of lateral slides from the RCP to the ICP.
The use of a cone and plate viscometer for determination of flow properties of unfilled resins and etching gels
Authors: TAVAS M. A. , WATTS D. C. 
Published: June 2007

SummaryA cone‐plate viscometer was employed for studying the rheological characteristics of certain unfilled resins and etching gels. Of these, BIS‐GMA monomer and its diluted mixtures exhibited Newtonian, dilatant and thixotropic behaviour depending on the shear rate. Other unfilled resins also exhibited various types of behaviour. At high shear rates reproducible hysteresis loops were obtained for etching gels which may be useful in characterization.
A 2‐year electromyographic study of patients with an immediate complete upper and a partial lower denture
Authors: TRYDE G. , TALLGREN A. , MIZUTANI H. 
Published: June 2007

SummaryA longitudinal electromyographic (EMG) investigation was performed on thirty subjects provided with an immediate complete upper and a partial lower denture. Electromyographic recordings in maximal clench, light tapping and postural position were obtained from the anterior temporal and masseter muscles before final extractions and 7 weeks, 6 months, 1 year and 2 years after denture insertion.The maximal clench activity of the jaw closing muscles showed an average tendency to decrease upon insertion of the dentures, but thereafter significant increases in mean voltages were observed during the first year of denture wear. During the second year no significant changes in EMG clenching force were noted. At the 2‐year stage most of the muscles showed significantly greater clench activity than at the post‐insertion stage, but did not exceed the pre‐extraction level.The jaw muscle activity in light tapping showed no significant mean changes during the observation period. The postural activity tended to decrease during the period of denture wear, the decrease being significant for some of the muscles at the 2‐year stage.
Alveolar ridge augmentation with bioactive glass ceramics: a histological study
Authors: SHAOAN WANG , ANYU CHEN , ZINENG YU , ZHANJIE HUANG , YUNMAO WAO 
Published: June 2007

SummaryA particulate BGC (bioactive glass ceramics), has been developed as a new bone graft biomaterial for alveolar ridge augmentation and has been evaluated by simulated animal models. Five beagle dogs were used in this investigation. Prior to augmentation the mandibular posterior teeth of the animals were extracted. Three months after the extractions, the porous BGC particles were packed into the subperiosteal tunnels in the ridges with a special syringe. The animals were killed at different time intervals and the specimens were examined by light microscopy, scanning electron microscopy (SEM), and X‐ray energy dispersive analysis (EDAX), respectively. The results of this study indicate that the BGC particles are firmly combined with the adjacent hard and soft tissues by the bone bonding interface between the implants and the alveolar bone, and by the ingrowth of bone or fibrous connective tissue into the interspaces and the pores of the particles. The results have demonstrated that particulate BGC with pores is an excellent implant material for alveolar ridge augmentation because of its very good biocompatibility.
Ultrastructure of the peri‐implant junctionalepithelium on single‐crystal sapphire endosseous dental implant loaded with functional stress
Authors: HASHIMOTO M. , AKAGAWA Y. , NIKAI H. , TSURU H. 
Published: June 2007

SummaryTo elucidate the Ultrastructure of peri‐implant junctional epithelium (IJE) on singlecrystal sapphire dental implants connected to the adjacent teeth by a metal superstructure, the peri‐implant gingivae of ten monkeys were examined using a transmission electron microscope (TEM) at 3, 6 and 12 months after implant insertion. At the time of examination, the ultrastructural features of the IJE were almost identical to those of junctional epithelium (JE) attached to natural teeth, i.e. developed Golgi complexes, rough‐surfaced endoplasmic reticulum, numerous free ribosomes and mitochondria. The innermost cells of IJE were attached to the implant surface by means of basal lamina‐like structures (500–1000 Å in thickness) and hemidesmosomes, but lacked a dental cuticle as seen on teeth. Such epithelial attachment of the IJE was often indistinct or absent at the apical portion of the IJE which terminated at the level of alveolar crest. A continuous basal lamina‐like structure was also present along basal cells at the interface between the IJE and gingival connective tissue except at its apical portion.