摘要:

SummaryProsthetic reconstruction was made on dentition affected by dentinogenesis imperfecta. The bite was first raised with fixed bite plates, and then with temporary acrylic bridges; finally full gold and veneer crowns were made in the posterior teeth. The crowns were retained on the severely attrited teeth with self‐threading parapulpal screws (TMS®, Whaledent International, New York, U.S.A.) and amalgam and composite resin (Consise®, 3M Company, St Paul, U.S.A.) posts. The teeth seem to have enough strength to withstand the occlusal forces, and the dentine appears hard enough to retain parapulpal screws. The prosthetic construction is still functioning well today, 5 years after starting treatm

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1981.tb00481.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SummaryThe variability of the EMG silent period in jaw closing muscles of TMJ dysfunction patients was examined. Considerable within‐subject variability was found in the duration of the silent period. This variability increased with symptom severity. The authors recommend that multiple measurements be averaged to obtain a more accurate estimate of the silent period duratio

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1981.tb00482.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SummaryThe stresses in the porcelain part of the last anchor crown in a cantilever bridge was analysed when loaded. The experiments were made with a model bridge. The load directions were vertical and horizontal. The critical load at the end of a four unit bridge was calculated to about 200 N. When the load direction was perpendicular to the axis of the pontic the critical load was estimated to 50 N.

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1981.tb00483.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SummaryA study was made to establish a norm for the frequency distribution of the size of particles produced by masticating a certain food item to its swallowable composition by normal dentate subjects. Only about 80% of the initial weight of food taken into the mouth could be recovered after mastication for particle size analysis. The particles ranged from 53 μm to 4750 μm, showing a positively skewed distribution with a mode value between 600 μm and 1200

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1981.tb00484.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SummaryThe effects of four lining materials, Dycal, Procal, Cavitec and Poly F cement on Adaptic and Concise have been investigatedin vitro. The parameters studied were surface roughness, hardness and colour both with and without an intermediate (or bonding) resin being present between the restorative material and the liner.The effects of the four liners on the composites varied both between the lining materials themselves and with the composite resin. Two materials, Procal and Dycal, had little interaction with the composites, provided an intermediate resin was used with the latter. Cavitec appeared to have an adverse reaction with the composites and Poly F, whilst having no effect on the colour of the composites, did increase surface roughness. The adverse effects of lining materials were ascribed to minor constituents, particularly methyl salicylate, present in the formulation.

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1981.tb00485.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SummaryThe potential of plasticized and polymerized acrylics to carry and release medicaments was investigated. Chlorhexidine acetate was incorporated at concentrations of 2, 5 and 10% into the powder phase of heat and cold cured acrylics and an acrylic gel soft liner. A preliminary bioassay demonstrated comparable release at anti‐bacterial levels from all three materials. Spectrophotometric and agar diffusion measurements of the chlorhexidine released into water showed the duration increased with the concentration of chlorhexidine incorporated. At 10% admixture the release from the polymerized and plasticized acrylics was in excess of 100 days. Light and scanning electron microscopy of polished and fractured surfaces of the polymerized acrylic showed the chlorhexidine distributed throughout the matrix of the materials. Following soaking in water, holes appeared in the matrix, particularly in the surface zones. Sections of the acrylic gel soft liner demonstrated chlorhexidine distributed as particulate material. Soaking in water caused vacuolation of the material and at higher concentrations material break‐up was appar

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1981.tb00486.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SummaryIntra‐bony defects are frequently observed around endosseous implants. It has been thought that these are due to occlusal loading and infection. More recently it has been suggested that they may be related to implant shape. This hypothesis has been tested using alumina implants with flat, cone shaped and flared ends, which were inserted into the mandibles and iliac crests of rabbits. The implants remainedin situfor up to 18 months and the tissue reaction was studied qualitatively and quantitatively using resin embedded histological sections. New bone was laid down parallel with the implant surface and at a pronounced angle to that in the cortex. Deep intra‐bony defects were seen adjacent to the flared implants and, to a lesser extent, the straight ones. Tapering implants appeared to encourage bone growth on the implant above the level of the cor

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1981.tb00487.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SummaryThe effects on the water uptake and weight loss of the incorporation of chlorhexidine acetate in heat cured acrylic and an acrylic gel soft liner was determined. Hardness and transverse bend measurement were similarly made for admixtures to heat and cold cured acrylics. Following soaking in water for 87 days the heat cured test specimens demonstrated an initial weight gain followed by a progressive loss, the soft liner test specimens however all showed weight gains. Drying back specimens to constant weight revealed significantly greater weight losses in test compared to control specimens for both the cured acrylic and gel liner. However these weight losses were less than the chlorhexidine content for 5 and 10% admixtures. Hardness and moduli of elasticity measurements were significantly reduced for heat and cold cured acrylics containing chlorhexidine. The property changes observed in the materials would be consistent with the pattern of incorporation of chlorhexidine into the matrix. However, these do not negate the carriage of medicaments in these materials for prolonged delivery within the oral cavity, if employed as rebase or reline materials in existing prostheses.

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1981.tb00488.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SummaryA technique has been developed for the preparation of test bars of the different types of aluminous porcelains using the standard laboratory procedures for the preparation of aluminous porcelain jacket crowns. Up to now the investigation of the properties of dental porcelain has been conducted using test specimens produced either by vibration of a slurry of porcelain powder without platinum foil or by grinding from the solid block. These techniques are far removed from the methods used for the production of porcelain restorations in the laboratory. This might lead to a variation in the results achieved by testing porcelain jacket crowns on the one hand and test specimens on the other.

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1981.tb00489.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SummaryA method is described which allows the tridimensional determination of the occlusal position. The device comprises an intra‐buccal transducer and a remote recorder where the signals received by microwaves are decoded, translated and recorded.The transducer is miniaturized and small enough to be placed within the wax rims of the bite plate of an endetulous patient. As the bite plate is comparable in size to the patient's future denture and the latter is not inconvenienced by wire coming out of his mouth, the experiment takes place in what are normal physiological conditions.The results achieved so far through preliminary clinical experience are encouraging. Further work is in progres

ISSN:0305-182X    

DOI:10.1111/j.1365-2842.1981.tb00490.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY