摘要:

SummaryThe present study examines (he function of fixed bridges on abutment teeth with reduced but non‐inflamed periodontal tissues. Eighteen patients with advanced periodontal breakdown and indication for oral rehabilitation received periodontal treatment and their dentitions were restored with fixed bridgework. The analysis of function performed 2‐5 years after insertion of the reconstructions was made by (1) evaluation of the patients' opinion on chewing ability and function of the masticatory system; (2) clinical examination of the border movements of the mandible, the status of the temporomandivular joints and the chewing muscles, and (3) measurements of the bite force in different areas of the dentition.The results of the study show that the functional capacity of the type of extensive bridgework discussed is good and that the patients–in spite of severe loss of periodontal tissue–achieve bite force values that are almost comparable to those in individuals with natural teeth. Comparison of the function of fixed bridges and that of removable dentures is also di

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1975.tb01521.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

SummaryThe effects of etching of the enamel, on the adaptation of silicate and Adaptic to the cavity walls was examined with the scanning electron microscope. Replica methods were utilized to ensure that no shrinkage of the filling materials was caused by the vacuum in the instrument. It was shown that following etching of the cavity margins, Adaptic adhered to the enamel with absent, or minimal, fissure formation on one side of the filling, and some on the opposite side. The adaptation of silicate to the margins of the cavities was not improved by etching.

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1975.tb01522.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

SummaryA study has been carried out to investigate possible differences between a group of dentulous young adults (average 22.5 years of age) and a group of dentulous elderly individuals (65.9 years), when attempting to recognize forms orally and to carry out tasks which demand a fine‐coordination of the oral muscular apparatus.The results showed, that the older group had reduced ability for both forms of tests used in this study (RF‐test for estimating the oral ability to recognize forms, and MA‐test to estimate oral muscular ability).The reduced capacity of the older individuals to learn the requirements of the tests as compared with the younger ones, was especially obvious. Furthermore, individual differences in this respect were more obvious for the older than for the younger examinees.The suggestion is made that in further studies the number of trial‐rounds may be reduced from three to two. certainly for older individuals and for both the RF‐ and the MA‐test.Because of the obvious correlation between the results of the RF‐ and the MA‐test among older individuals, it is concluded that both forms of tests may measure common or closely related factors, which are reflected

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1975.tb01523.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

SummaryThein vitrochloride corrosion behaviour of Dispersalloy has been investigated by anodic polarization as a function of time after trituration (ageing) and compared with conventional dental amalgam. Dispersalloy is a commercial alloy containing a mechanical mixture of Ag3Sn and Ag–Cu eutectic in the ratio 2:1. From measurement of 1 h corrosion potentials it was observed that over a time period of 1 year Dispersalloy became appreciably more noble (potential shift from –500mV to – 350 mV Vs. SCE), whereas the corrosion potential of conventional amalgam remains unchanged.Initial anodic polarization profiles for Dispersalloy indicated presence ofy2and Cu6Sn5phases as evidenced by presence of the –250 mV peak. However, the current density associated with this peak was about three times less than that of conventional amalgam. As a function of ageing time the polarization profile is shifted in the direction of decreasing current density and after 1 year the –250 mV peak is absent. The anodic polarization profile of conventional amalgam is unchanged after 1 year. The improved corrosion resistance of Dispersalloy is attributed to the formation of Cu3Sn as a function of time due to solid state reaction between Ag–Cu eute

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1975.tb01524.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

SummaryCheek pressure during swallowing was measured on six operated complete cleft lip and palate cases (4–8 years of age) before and after expansion of buccal segments of maxillary arch, As control, seven non‐cleft subjects with acceptable occlusion of the same age level were used. Before expansion, the pressures in the cleft cases were much higher than the controls. Immediately after expansion, increase in pressure was observed in cases which received rapid expansion. However, a few months after expansion, most cases showed a decrease in pressure. This is explained as being due to the adaptation of the perioral musculature to the expanded dental arch and/or the disappearance of hyperactivity of the perioral musculature during swallow

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1975.tb01525.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

SummaryAlloying or admixing of a dental amalgam alloy with an element or alloy which has a higher affinity for tin offers a means for eliminating the corrosion prone γ2phase. Accordingly, the corrosion behaviour of non‐conventional amalgams containing Cu and Au were investigated by anodic polarization studies in Ringer's solution. The Cu containing amalgams were produced by admixing Cu‐Hg (copper amalgam) with conventional amalgam in the ratios of 0.5:1 and 1:1. A 10 w/o Au in Ag3Sn was used as the gold amalgam alloy. The anodic polarization profile of the 0.5:1 Cu admixed was similar in shape to conventional amalgams although current densities were less. After ageing for I month the – 250 mV peak associated with γ2disappeared and the current density decreased by ten fold. After2months the current density decreased by one hundred fold. The anodic polarization of the 1: 1 Cu admixed amalgams did not display the ‐250 mV (γ2) peak after 1 week and current densities were I03below that of conventional amalgams. The behaviour of these interesting amalgams is rationalized on the basis of the ease of formation of Cu‐Sn intermetallics where Cu/Sn>3. The anodic polarization profile of 10 w/o Au containing amalgam essentially is that of conventional amalgam and does not change drastically after 6 months. Although the Au may reduce or eliminate the γ2phase the resulting AuSn4apparently corrodes in an analogous fashion. However, since distribution of AuSn4may be different from γ2, i.e. not continuous, the effect of corrosion on its mechanical properties ma

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1975.tb01526.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1975.tb01527.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

SummaryA review of recent literature on the effects of experimental hyperactivity of the mandibular locomotor system of man is presented, with special reference to the effects on the nervous, muscular and vascular components of this locomotor system.

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1975.tb01528.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

SummaryA method for studying the linear dimensional changes of dental cements during setting has been described. The measurements started 3 min after commencing the mix with specimens placed on a mercury bath. Measurements were performed at 37°C a.nd under various environmental humidity.The specimens were made of a fine grain zinc phosphate cement with high powder/ liquid ratio (3/1: g/ml) and low powder/liquid ratio (2/1: g/ml), and the measurements showed that the cement contracted during setting under both wet and dry conditions.Under wet conditions cements with both high and low powder/liquid ratio showed the same contraction, with 0.43% after 30 min reaching a maximum of 0‐66% after 1 day.Under dry conditions the contraction was more pronounced, and somewhat dependent on the powder/liquid ratio. The cement with the high powder/liquid ratio showed 1.33% contraction after 30 min with a maximum of 3.83% after 7 days, whereas the corresponding values for cement with low powder/liquid ratio were 0.79% and 4.7

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1975.tb01529.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

SummaryThe radiological features seen on the temporomandibular joint radiographs of ninety‐nine cases of adult rheumatoid arthritis were used to distinguish this group from a group of eighty‐three control subjects using the method of logistic discrimination. A readily calculable diagnostic score, whose value was verified by a second study involving thirty‐two patients, sixteen of whom suffered from adult rheumatoid arthritis, was estimated. This second study was further used to illustrate how this scoring system would be modified to take account of extra information. Although a long term evaluation of the method is envisaged its clinical application is indicated and its practical value demonst

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1975.tb01530.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY