摘要:

SummaryAn analysis of the distribution of tooth losses in 521 subjects having lost one to fourteen teeth, disclosed a statistically significant association between the loss of maxillary first premolar and the presence of TMJ dysfunction. The association was evident on both sides. Maxillary first premolars have earlier been shown to contact prematurely on hinge closure more often than the other teeth. The loss of other teeth seemed independent of the functional state of the stomatognathic system. It is suggested that TMJ dysfunction may predispose to the loss of the maxillary first premolar by direct trauma to the tooth and/or by speeding up periodontitis.

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1985.tb00635.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1985.tb00636.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

SummaryAn association was sought between certain morphologic characteristics of malocclusion—Angle classification, over‐bite, over‐jet, open‐bite, cross‐bite and crowding—and the presence or absence of three cardinal symptoms of mandibular dysfunction—joint sounds, joint sensitivity to palpation and muscle sensitivity—in a sample of 369 1 school children. In addition, two additional independent variables, ‘occlusa, wear’ and ‘previous orthodontic treatment’ were introduced into the statistical analysis.Occlusal wear and abnormal overbite were the only factors found to increase significantly the presence

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1985.tb00637.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

SummaryThe aim of this study was to determine the pulpal response to three dilute citric acid smear removers. Forty‐eight vervet monkeys (Cercopithecus aethiops pygerythrus), in three groups of sixteen animals provided 384 tooth specimens for the histological evaluation of the pulpal response at 3, 31, and 59 days post‐operatively. Labial Class V cavities were prepared in the maxillary and mandibular incisor teeth. The pulpal responses elicited by 1% aqueous citric acid, 1% citric acid in 30% ethanol and 0.1% citric acid in 30% ethanol solutions, in unlined cavities and in cavities lined with Dycal after acid application, were compared with those elicited by a negative control material—(Nobetec), and a positive control material—(Syntrex). Using Stanley's criteria the most severe pulpal responses were seen in teeth treated with 1% aqueous citric acid and 1% citric acid in 30% ethanol without a subsequent liner, and by Syntrex at all three time intervals. The use of Dycal as a liner after smear removal markedly reduced the pulpal re

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1985.tb00638.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

SummaryIn thisin vitrostudy the marginal leakage of three composite systems—Sevriton, Consize and Isocap—has been quantified as a function of time.The method used (v.d. Veenet al., 1984) consists of the determination of the amount of nitrogen gas passing through restoration margins at 2 atm.The results show that the marginal leakage of all composites decreased strongly with time and became negligible after about 1 month. If we rank the three systems investigated according to their marginal leakage we have Consize>Isocap>Sevriton. The data suggest that water uptake and subsequent expansion of the polymers account for the leakage decre

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1985.tb00639.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

SummaryNon‐precious metal crowns were prepared for natural teeth which were ground to a taper angle of 5°. The movement of the crowns on teeth during repeated try‐on seating was measured with a micrometer. Increasing the applied load from 2 to 10 kg resulted in an average crown movement of 63 μm. For most samples this movement continued when try‐on was repeated. Casting irregularities were found to create furrows on some regions of the axial tooth surface during try‐on seating. The diameter of the ADA specification consistency disk for zinc phosphate cement was found to depend strongly on the P: L ratio and the ambient temperature. The castings were cemented with zinc phosphate cement of controlled consistency. Cementation with a load of 10 kg gave rise to an average crown elevation of 54 μm and a range of measurements between −8 and 113 μm. The effective minimum cement thickness corresponding to this average was calculated to be 4.7 μm. Small negative values of elevation were attributed to deepening of tooth furrows during cementation. An analysis is given of data from the literature, relevant to the cement flow and irregularities in ce

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1985.tb00640.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

SummaryA consecutive series of eighty‐seven saddle‐bridges with free‐end saddles, executed by the author during the years 1958‐72, was investigated in 1982. The aim was to assess the long‐term prognosis.Five years after application 98% of the bridges were still functioning. The corresponding percentage after 10, 15 and 20 years was 82, 69 and 49%, respectively. The risk that saddle‐bridges cease to function is very low during the first 5‐year period but significantly higher thereafter.Soldering fractures constitute an important cause of the removal of appliances during the first 8 years following application. After this time the most frequent causes are caries and loosening of the teeth.Factors such as sex, time of application, patient's age, length of saddle and whether the bridges were fitted in the mandible or maxilla, have not had a significant influence on the prognosis. Furthermore, no statistically significant difference has been found between the long‐term prognosis for full and partial saddle‐bridges. On the other hand, patients with a removable full denture in the opposing jaw show a significantly worse prognosis (P<0.05) than patients without a denture in this jaw.The results of the present study indicate that the short‐term prognosis for saddle‐bridges is very favourable and that the long‐term prognosis is so good that saddle‐bridges can constitute an alternative therapy even in jaws with as few

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1985.tb00641.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

SummaryMovement of teeth during denture processing is an unsolved problem. This study investigates the amount of vertical tooth movement during controlled processing of acrylic, using 33° and 0° teeth invested in specific mixes of plaster of Paris or dental stone.Forty sample set‐ups each containing four posterior teeth were processed under strictly controlled laboratory conditions. Twenty of these samples carried 33° teeth and the other twenty carried 0° teeth. Each group of twenty samples was randomly divided on a factorial design into batches of ten for investment in plaster of Paris or stone. The vertical movements were measured with a greater degree of accuracy than is required for clinical application. All results were analysed statistically.Significantly greater movement occurred with teeth invested in stone than those invested in plaster of Paris. Whereas, for teeth invested in stone, significantly greater movement occurred with 33° than with 0° teeth, no such effect was found with teeth invested in plaster o

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1985.tb00642.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY