摘要:

SummaryBy means of videofluoroscopic recordings, chewing, swallowing and speech were monitored in nine patients with congenital and acquired maxillary defects. All of them were rehabilitated with a maxillary obturator prosthesis. The defective region was seldom used for chewing. No leakage between the obturator and surrounding tissue was observed, either for solids or for liquids. All of the prosthetic reconstructions were surprisingly stable during function. In the phonetic analysis, speech production was judged to be restored almost to normal. Videofluoroscopy may be valuable as a complement to other functional diagnostic procedures, and for the evaluation and improvement of rehabilitation with an obturator prosthesis.

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1991.tb00069.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SummaryA total of 142 failed bridges constructed in general dental practice were assessed for design factors that might relate to failure. The overall mean age of the bridges at failure was 6.2 years; anterior and complex bridgework had a mean age of about 5 years, compared with 7.5 years for posterior bridges. The lifespan of the bridgework was significantly correlated with the number of retainers but not with the number of units. Bridges with one or two retainers had an average lifespan of just over 7 years, whilst those with three or more retainers had been in service for, on average, only 4 years. The practical difficulties of constructing multi‐abutment bridgework could account for this difference. One hundred and ninety‐one of the 346 retainers were porcelain bonded to semi non‐precious metal crowns, and had a mean lifespan of 3.7 years, whilst those that were gold based lasted at least twice as long. Post crowns as retainers survived on average for 6.2

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1991.tb00070.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SummaryThe history and clinical symptoms of anterior temporomandibular joint disc displacement without reduction are characteristic, and include limitation of mandibular movement and mandibular deviation on opening of the mouth. Twelve consecutive patients attending a clinic with such symptoms were treated by mandibular manipulation. An immediate increase in the range of mandibular movement was obtained for all patients, with a mean increase in interincisal opening of 8mm. The method of manipulation is described, and the implications of the results for the treatment of TMJ patients are discussed.

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1991.tb00071.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SummaryThe in‐situ remineralization effect of hard cheese was compared with that of saliva on tooth enamel in man. The intra‐oral test of softening enamel surfaces by a cola type drink followed by rehardening by chewing hard cheese and/or parafilm was assessed by microhardness and SEM measurements. Cheese consumption significantly increased the enamel hardness, whereas stimulated saliva did not have this effect. The remineralizing effects are presumably due to uptake of calcium and phosphate salts by the surface enamel. Morphologically, the enamel surfaces did not return to their original st

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1991.tb00072.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

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 collage

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1991.tb00073.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SummaryThe masseter, temporalis anterior and digastric anterior muscles of five volunteers have been investigated by means of surface electromyography. Each muscle was tested by three operators at different times and under three distinct conditions of intermaxillary relationship: resting, with no occlusal contact (physiological rest position); occlusion in centric occlusion (C.O.) without clenching force; and maximum voluntary clench. In all the trials the BIO‐PAK system (Bio‐Research Associates Inc., Milwaukee, WI, USA) was used. Measurements were made in two consecutive experimental trials separated by an interval of about 15 days. In the first trial the operators had minimal instrumental experience. while in the second trial the same operators had performed at least 30 measurements each. The data have been analysed by a factorial variance analysis, particularly with a view to comparing the variability between operators for each volunteer subject. The analysis revealed statistically significant differences only in the first experimental trial, due to the operators' lack of experience. The study demonstrates that the electromyographic system and protocol used allow good reproducibility of measurements. Furthermore, they have potential applications in both clinics and resea

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1991.tb00074.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SummaryThe present in‐vitro study was designed to investigate the chemical efficacy of N‐monochloro‐D,L,‐2‐aminobutyrate (NMAB, GK 101E) in removing carious material under clinically relevant conditions, using objective methods of measurement. Assuming that the chemical effectiveness of water in caries removal is minimal, a comparison of the efficacy of GK‐101E with that of water was made. The force required to achieve complete caries removal from symmetrically separated carious lesions was determined with the CaridexTMsystem, modified by a force gauge. One lesion half was treated with GK‐101E, while the corresponding half was treated with water. Thus a difference in the chemical potential of the fluids in softening carious material should lead to a difference in the force required to remove equal quantities of caries. Statistical analysis of the findings of the present study revealed no significant difference between GK‐101E and water, with regard to both the force and the number of excavation strokes and the time needed for caries removal. It is concluded that, under the given test conditions, the removal of carious dentine is not significantly enhanced by the chemical ac

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1991.tb00075.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SummaryCephalometric analyses have long been important diagnostic tools for the orthodontic specialist. Such analyses, as they pertain to adult skeletal problems and their consequent therapy, should also be a valuable adjunct for various dental specialties, e.g. the oral surgical clinician. However, because of the complexity of most analyses, it is difficult to glean the important values needed for most orthognathic cases. In this article an analysis is presented to aid the clinician in surgical diagnosis and treatment planning.

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1991.tb00076.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SummaryVoids presenting in impressions of five automixed addition silicone elastomers were investigated. Impressions were prepared with the putty‐light body impression technique on stainless‐steel cylinders with acrylic spacers. The number of voids was counted at a predetermined site on three separate days using a stereomicroscope at x7 magnification. Impression specimens of a hand‐mixed addition silicone, and from hand‐mixing of the automixed materials, were made for comparison. Express gave a significantly higher number of voids than other automixed materials, with President Jet having the lowest void count. Automixed materials generally produced impressions with significantly fewer voids than the hand‐mixed material. Automixing was effective in reducing void defects in elastomeric im

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1991.tb00077.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SummaryTo determine the relative contribution of the masseter and anterior temporalis muscles to global isometric bite force, activity indices were constructed on the basis of the peak mean voltage (μV) and the integrated voltage (μV.s) of bipolar surface electromyograms obtained during brief maximum voluntary teeth clenching (MVC). The index that was based on integrated myoelectrical activity showed that the masseter muscle contributed the major part of the isometric MVC force. The index that was based on instantaneous peak myoelectrical activity also showed that activity in the masseter muscle predominated over that in the anterior temporalis muscle. In addition, the latter index showed a negative linear association with the initial (0–50% MVC) isometric contraction velocities of the masseter and anterior temporalis muscles. Both indices appear to be promising clinical diagnostic to

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1991.tb00078.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY