摘要:

Øilo, G. The extent of slits at the interfaces between luting cements and enamel, dentin and alloy.Four different cements were used to assess the presence of slits at the cement/tooth or the cement/alloy interfaces using a tooth-crown model. The model consisted of ground sections of teeth and plane plates of silver/palladium alloy. The plates were fixed with bolts between two brass plates and with three different dimensions of the cement film between tooth and alloy, i.e. 50μm, 100μm and 200μm. The tooth-alloy specimens were sectioned and the adaption of cements was studied with an indirect technique (replica) in a scanning electron microscope. The extent of slits was expressed as the length of all slits relative to the total length of the interface in each specimen.The results showed that the zinc phosphate cement and poly carboxylate cement exhibited a slight to moderate tendency to formation of slits at the interfaces. The EBA cement had a small extent of slits adjacent to thin cement films, but more slits were observed with increasing film thickness. The composite resin cement had a marked tendency to slit formation independent of the cement film thickness.

ISSN:0001-6357    

DOI:10.3109/00016357809029074

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

ISSN:0001-6357    

DOI:10.3109/00016357809029075

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

Øilo, G. Adhesive bonding of dental luting cements; influence of surface treatment.Tensile bond strength of four different luting cements to smooth dentin surfaces was measured. A chisel edged, stainless steel ring was cemented to the butt end of a dentin cylinder. The dentin was polished to a plane and smooth surface before cementation. The cements were also applied to dentin surfaces that were treated with a pumice slurry, etched with different acid solutions, or covered with different liners.The results showed that the polycarboxylate cement had a tensile bond strength to smooth, untreated dentin of approximately 4 MN/m3. The zinc phosphate and EBA cements had a bond strength of 0, 6 MN/m2and the composite resin cement had no measurable bond to untreated dentin.All dentin treatments showed in general a decreasing effect on the bond strength of zinc phosphate, polycarboxylate and EBA cements, whereas that of composite resin cement showed a slight increase.

ISSN:0001-6357    

DOI:10.3109/00016357809029076

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

Bawden, J.W., Wennberg, A. Hammarström, L. In vivo and in vitro study of5 9Fe uptake in developing rat molars.Autoradiographic methods were used to study59Fe uptake in vivo in mineralizing tissues of young rats. Localization of5 9Fe was observed in the ameloblastic layer of molars. In vitro studies were performed which demonstrated that5 9Fe uptake in developing rat molar enamel was limited by the metabolic activity of the cells of the enamel organ.

ISSN:0001-6357    

DOI:10.3109/00016357809029077

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

Lie, T. Gusberti, F. Dental plaque morphology as revealed by direct observation and by replicating techniques.The ability of four elastomer impression materials to reproduce details of bacterial plaque structures was studied by comparing areas of the replica models with corresponding areas of the replicated plaque. Plaque was grown on hydroxyapatite splint segments for 48 hours and replica models were made from three different resins. One of the resins, a methacrylate material, was not suited for this purpose due to its content of spherical particles. The polysulfide and polyether impression materials reacted with the heat curing epoxy resin, and less satisfactory results were obtained with cold curing epoxy resin. Best results were obtained by a combined use of low viscosity silicone impression materials and cold or heat curing epoxy resins as model materials. However, a considerable loss of detail occurred in the replica models compared with observations of plaque directly on splint surfaces. Outlines of individual bacteria could sometimes be seen in the models, but generally several cells seemed to fuse, and appeared lie small globular structures where cells and pellicle were difficult to distinguish. The bacterial colonization started near the gingival border of the surface, initiated by attachment of individual bacteria to the pellicle surface.

ISSN:0001-6357    

DOI:10.3109/00016357809029078

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

Baier, R.E. Glantz, P.-O. Characterization of oral in vivo films formed on different types of solid surfaces.Studies were made of oral films formedin vivo, which had been allowed to form on fused silica and Ge-prisms during periods between 2 s and 2 h using a variety of physico-chemical methods. To produce surfaces of different qualities the silica and Ge-prisms had either been detergent-washed, glow discharge treated or covered with polydimethylsiloxane. The following simultaneous analytical techniques were performed on the adsorbed films: a. internal reflection infrared spectroscopy, b. ellipsometry, c. contact potential measurements, d. contact angle measurements, e. scanning electron microscopy and f. energy-dispersive x-ray analysisThe results of these studies show that the formation of oral films proceeds at high speed and is of a certain qualitative selectivity. The formed films were found to be stable over long periods of time, and only showed patches of adhering micro-organisms on some of the prisms which had been exposed in the oral cavity for 2 h.

ISSN:0001-6357    

DOI:10.3109/00016357809029079

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

Gjerdet, N.R. Hegdahl, T. Porosity of resin filling materials.Four paste-paste types of resin filling materials and three capsulated products were tested with respect to porosity content and size distribution of the pores. The data were obtained by using an automatic image analyzer. The paste-paste products were inserted into the test cavities by a bulk-packing technique and an injection technique. The results showed that the use of a syringe reduced the porosity content, mainly by the elimination of big pores. The capsulated products were not less porous than the paste-paste materials.

ISSN:0001-6357    

DOI:10.3109/00016357809029080

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

Pancherz, H. Anehus, M. Masticatory function after activator treatment. An analysis of masticatory efficiency, occlusal contact conditions and EMG activity.Masticatory function was investigated in nine patients with relapse and ten patients without relapse of overjet after activator treatment, Masticatory efficiency, evaluated by a chewing test, was related to the number of intermaxillary tooth contacts and the electromyographic (EMG) activity from the temporal and masseter muscles during chewing. The results of the investigation indicated that a reduced masticatory efficiency was connected with fewer intermaxillary tooth contacts and less EMG activity from the temporal and masseter muscles. In patients with relapse of overjet, masticatory efficiency and muscle activity was reduced in comparison with patients without relapse. The relationship between the number of tooth contacts and masticatory efficiency was poor in the relapse patients. Unstable occlusal conditions and atypical tongue function may be an explanation.

ISSN:0001-6357    

DOI:10.3109/00016357809029081

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

Øilo, G. Sealing and retentive ability of dental luting cements.The present summary and the following papers (I—VIII) are submitted in partial fulfillment of the requirements for the degree of Doctor Odonto-logiae at the University of Oslo.I Linear dimensional change during setting of a zinc phosphate cement. A methodological study. J. Oral Rehabil. 1975, 2, 179–185II Linear dimensional changes during setting of two polycarboxylate cements. J. Oral Rehabil. 1976, 3, 161–166III Linear dimensional changes of three luting agents. J. Oral Rehabil. 1977, 4, 395–399Coauthor: E. AmbjeirnsenIV Adaption of luting cements to enamel, dentin and restorative material. Acta Odontol. Scand. 1978, 36, 149–156V Extent of slits at the interface between luting, cements and enamel, dentin and alloy. Acta Odontol. Scand. 1978, 36, 257–261VI Adhesive bonding of dental luting cements: Influence of surface treatment. Acta Odontol. Scand. 1978, 36, 263–270VII Stresslstrain behaviour of some dental luting cements. Acta Odontol. Scand. 1978, 36, 45–49Co-author: S. EspevikVIII The influence of surface roughness on the retentive ability of two dental luting cements. I. Oral Rehabil. 1978, in pressCo-author: K. Dreyer JørgensenThese papers are referred to as Papers I—VIII in the present summary. Other papers are referred to in normal manner.

ISSN:0001-6357    

DOI:10.3109/00016357809029082

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor

摘要:

Daftary, D.K., Pitkar, V.K., Cupta, P.C., Pindborg, J.J. Mehta, F.S. A study of the natural history of oral preleukoplakia.A preleukoplakia, conceived as a precursor stage of leukoplakia, is grey or greyish-white area with indistinct borders. The paper describes 659 preleukoplakias detected among 20, 358 individuals in two districts in India. In Bhavnagar district 99.5 % of the preleukoplakias were among men. 23.5% of the hookli (clay pipe) smokers had preleukoplakias. In Ernakulam district 79.6 % of the preleukoplakias were found among men and the mixed habit group of bidi smoking and tobacco chewing had the highest prevalence (6.1 %). The preleukoplakias showed a marked tendency to regress; among the bidi smokers in Bhavnagar, 75 % regressed. In two patients preleukoplakia turned into carcinoma.

ISSN:0001-6357    

DOI:10.3109/00016357809029083

出版商:Taylor&Francis    

年代:1978

数据来源: Taylor