摘要:

Eighteen volunteers were given a mouth rinse with a 50 per cent sucrose solution and the pH of superficial dental plaque was measured electrometrically after 2, 5, 10, 20 and 30 minutes either when the person was continuously chewing paraffin or without paraffin chewing. The paraffin was chewed on one side of the mouth and the samples for measurement of the pH were taken from the other side of the mouth. In one series of experiments paraffin was chewed but the mouth was not rinsed with the sugar solution. The results revealed that the pH-decrease caused by the sugar rinse was diminished significantly by chewing. Chewing paraffin raised the pH by about 0.4, compared with the initial pH-values recorded after 10 minutes. This pH-increase lasted throughout the experimental period of 30 minutes. The difference was statistically significant.

ISSN:0001-6357    

DOI:10.3109/00016357409002536

出版商:Taylor&Francis    

年代:1974

数据来源: Taylor

摘要:

The number of teeth, the frequency of dentitional, space and occlusal anomalies and the need of orthodontic treatment was studied in 301 Swedish men from the west and south of Sweden with a mean age of 18 years 8 months. Dentitional anomalies (abnormal number and morphology of the teeth and positional anomalies of front teeth) as well as crowding, spacing of the teeth and occlusal anomalies were noted. The objective need of treatment was judged according to a 5-grade scale. The number of missing teeth (exclusive of third molars) was, on the average, 0.8 per individual. Dentitional anomalies were recorded in about 35 % of the individuals and space anomalies in 52 %, while the frequency of occlusal anomalies was about 65 %. About 60 % of the individuals were judged as beeing in need of some form of orthodontic treatment. The need of treatment was small in about 30 %, while about 20 % had a more substantial need and almost 10 % severe need.

ISSN:0001-6357    

DOI:10.3109/00016357409002537

出版商:Taylor&Francis    

年代:1974

数据来源: Taylor

摘要:

The awareness of a person of any dentitional or occlusal anomaly and his desire to receive orthodontic treatment was studied in a group of 18-year old men in whom such anomalies had previously been diagnosed by an orthodontist. The desire for treatment and awareness of the anomalies were studied from answers to questions bearing on the state of the teeth and occlusion. About 16% of the men had received earlier orthodontic therapy with appliances.Good agreement was found between the actual frequency of individuals with missing teeth and the frequency who reported that teeth had been extracted or were missing for some other reason. The frequency of awareness of dentitional, space or occlusal anomalies, on the other hand, was low, especially for anomalies in the lateral segments. Awareness of anomalies and the desire to receive orthodontic treatment were equally frequent for anomalies in the upper and lower jaws, but varied somewhat with type of anomaly. Only 4% of the individuals thought that they needed orthodontic treatment although as many as 60% were judged by the orthodontist to be in need of such treatment, and in half of these individuals the need was considerable.

ISSN:0001-6357    

DOI:10.3109/00016357409002538

出版商:Taylor&Francis    

年代:1974

数据来源: Taylor

摘要:

Sodium deoxycholate was used to release peptidase and alkaline phosphatase activities from saliva sediment. The degree of the release was determined at a variety of detergent concentrations and incubation periods. By use of 0.4% of this detergent 80% of the alkaline phosphatase found in the sediment was released. A twofold increase in peptidase in the soluble fraction (10,000 g supernatant) and a 10% increase in protein resulted in the same concentration of sodium deoxycholate. The distribution of the enzymes in saliva supernatant and the enzymes released from sediment were determined on the substrates gelatin, poly-L-lysine HBr, haemoglobin,a-N-benzoyl-L-arginine ethyl ester-HCl,p-tosyl-L-arginine methyl ester-HCl, L-lysine-p-nitroanilide HBr andp-nitrophenyl phosphate. The study indicates that the peptidase(s) soluble in human saliva without detergent are derived from saliva sediment.

ISSN:0001-6357    

DOI:10.3109/00016357409002539

出版商:Taylor&Francis    

年代:1974

数据来源: Taylor

摘要:

Aminopeptidase activity of normal and mechanically strained rat gingiva was studied using variousN-L-aminoacyl-2-naphthylamine derivatives as substrates. Mechanical occlusal strain was directed to the first and second molar. The healing was studied 1, 3, 8 and 12 hours after the treatment. The mechanical treatment caused the disappearance of a gingival aminopeptidase which was inhibited by 0.2 M NaCl. This enzyme reappeared in the eight hour samples. All tissue samples (of the strained and control tissue) contained an enzyme so closely related to the rat liver aminopeptidase B (APB) that the presence of a true APB in rat gingiva was considered to be very likely. The activity of APB increased during the first hours, but this took place almost equally in both control and strained tissue, an indication that the strong mechanical treatment had also affected the control tissue of the test animals. The mechanical treatment used led to disturbances in the content of the studied enzymes in gingiva. The healing of the tissue, however, restored the initial situation within eight or twelve hours.

ISSN:0001-6357    

DOI:10.3109/00016357409002540

出版商:Taylor&Francis    

年代:1974

数据来源: Taylor

摘要:

A neutron activation method for the determination of rare earths in hard tissues was developed and the concentrations of some of these elements in human dentine and enamel were determined. The results obtained for La, Sm, Tb and Yb are very low, indicating a total rare-earth content of the order of 0.1 ppm or less in the samples investigated. The observed La/Sm ratios seem to indicate a slight enrichment of the lighter rare earths relative to the heavier, as compared to average geological abundances.

ISSN:0001-6357    

DOI:10.3109/00016357409002541

出版商:Taylor&Francis    

年代:1974

数据来源: Taylor

摘要:

Holographic interferometry, an application of laser technology, was introduced as a non-contact and non-destructive method for investigations concerning the dynamics of human teeth and prosthodontic appliances in function. The method was first tested in a simulator and then used in a number of clinical experiments. A special, totally reflecting paint was used for surface preparation prior to holography. A Q-switched double-pulsed ruby laser with a pulse-length of 24 ns was combined with an electronic subminiature force sensor for pulse triggering which was actuated by the masticatory force of the patient. Force increase and pulse positions were registered synchronously on the screen of an oscilloscope. The applied force exerted by the patient's masticatory muscles could thus be defined according to its point of application, direction, amplitude and duration. The corresponding surface deformation was evaluated by means of a synchronized, double exposed hologram. The measuring range as well as the sensitivity of the method depend on the wavelength of the ruby laser light (0.6943μm). Conclusions could be drawn regarding the relative and absolute mobility of the teeth and related structures of the holographed jaw section. The technique provided abundant and detailed information, its documentation being facilitated by means of a special photographic method.

ISSN:0001-6357    

DOI:10.3109/00016357409002542

出版商:Taylor&Francis    

年代:1974

数据来源: Taylor