摘要:

abstract—Enamel organs in developing teeth of young rats were studied after single intra peritoneal injections of a high dose of sodium fluoride (60 mg NaF/kg body wt.). The study employed primarily light microscopy, but electron microscopy was used to clarify some of the light microscopic findings. The pathogenesis of the fluoride‐induced changes was followed during 72 h. Cellular changes were consistently found in the molars, but were never seen in the incisors. In the maxillary molars, ameloblastic injury was most commonly seen on the mesial surfaces of the cusps. One hour after injection, the most prominent findings were swollen mitochondria in the secretory ameloblasts and cleft formations between the ameloblasts and the enamel matrix. The clefts were filled with a stippled material. Some of the clefts gradually expanded to cystic cavities. The stippled material began to calcify after 24 h and formed small, darkly stained globules. After 72 h dearranged ameloblasts were found as islands intermingled with calcified rounded structures in the stellate reticulum. In stratum intermedium numerous atypic autophagic vacuoles appeared 2 h after injection. No light microscopic changes were observed in the postsecretory amelobla

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1978.tb00621.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

abstract—On the basis of the number ofStreptococcus mutansand lactobacilli, 645 children 9–12 years old were divided into five groups. The children with the highest number ofS. mutansand lactobacilli were considered to be at a high caries risk and were divided into three groups with 49 children in each. One group received preventive measures from a specially trained nurse twice a month, one group was treated once a month and the third group served as a control. The other 498 children with lower numbers ofS. mutansand lactobacilli were considered to be at a lower caries risk and were divided into two groups. One group was treated once a month while the other was a control. The children with originally high numbers ofS. mutansand lactobacilli developed significantly more new carious lesions after 1 and 2 years (2.5 and 4.3) than the children with low counts in the control groups (1.9 and 2.8). All the children in the test groups which had receivedthepreventive program developed significantly less caries than the corresponding control group. In the test risk group treated twice a month the caries activity was extremely low during the 1st year with an average of 0.34 new carious lesions. After 2 years the average was 0.92. The microbial conditions as well as the saliva secretion rate, buffer capacity and saliva pH did not seem to be influenced by the preventive prog

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1978.tb00622.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

abstract—Plaque formation and caries development were studied in 0‐M rats fed Diet 2000 and infected withS. mutans6715 and fecal flora from older caries‐active rats. Merck dextranase, Beckman dextranase or Beckman glucanase 447 were administered singly or in combination to groups of 12 rats either as an addition to the diet or as a “mouthwash” twice daily, 5 d per week. All enzymes studied were associated with significant inhibition of both plaque formation and caries development, especially on the buccal and lingual

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1978.tb00623.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

abstract—The influence of experimental neutropenia on the wound healing process in standardized excisional palatal wounds was studied in 16 guinea pigs. Corresponding wounds in 15 normal animals were used as controls. Neutropenia was induced and maintained by daily injections of heterologous anti‐neutrophil serum. One‐micron sections from biopsies of palatal mucosa sampled 6, 24, 48 and l20h after wounding were evaluated with special reference to the progress of epithelial wound repair and to the occurrence and location of inflammatory cells and bacteria. In animals treated with antiserum, neutrophilic leukocytes disappeared from the wound cavity, whereas other inflammatory cells remained unchanged. Further bacterial invasion deep into the cavity was observed. The epithelial repair took place at a deeper level in the wounds of neutropenic animals compared with those of normal animals. The rate of re‐epithelialization was the same in neutropenic and control wounds. The experiment indicates that the neutrophils in oral wounds provide a principal agency for host defense against microorganisms and probably thereby indirectly determine the direction and level of epithelial cell mi

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1978.tb00624.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

abstract—Acid production activity (APA) in plaque suspensions from glucose, boiled soluble starch and hydrogenated starch hydrolysate (Lycasin®) was studied in 11 subjects. Amylase (alpha‐1,4‐glucan 4‐glucanohydrolase, EC 3.2.1.1) activity was measured in plaque and whole saliva samples from the same persons. Lycasin was found to be hydrolyzed by salivary amylase under the formation of di‐ and oligosaccharides, however, with a lower rate than starch. A high correlation was found between APA from glucose and from soluble starch and between APA from soluble starch and plaque amylase activity. No correlation was found between amylase activity in saliva and APA from soluble starch or between amylase activity in saliva or plaque and APA from Lycasin. APA from Lycasin was about 62% and from soluble starch about 76% of the APA from glucose. 0–25% of the total number of cultivable microorganisms from the plaque produced extracellular starch‐degrading enzymes. No correlation was found between number of starch‐degrading microorganisms and APA from soluble starch or between these numbers and the plaque amylase activity. By electrophoreses only amylase fractions of human origin were found in whole saliva, plaque supernatants and plaque suspensions, indicating that the microbial amylase activity in the plaque is low compared with that of

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1978.tb00625.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

abstract—Pulpotomy in primary teeth using the formocresol method results in varying degrees of devitalization of the root pulp. The extent of this devitalization depends on, among other things, the ability of the components of formocresol to leave the dressing. The purpose of this study was to evaluate the rate and duration of diffusion of the components of formocresol when incorporated in different vehicles. The antimicrobial effect of the drugs was used to assess the diffusion of the components of formocresol in blood agar, with a sensitive microorganism as an indicator. Evaluation of the MICs assessed in broth medium for formalin, formocresol and cresol, respectively, and the zone size of growth in hibition on blood agar from these components when incorporated in ZnO or ZnO‐eugenol cement, suggested that the initial zone of inhibition from formocresol was due mainly to the diffusion of formaldehyde. Cresol diffused more slowly from the dressing. The presence of eugenol in the dressing, as in ZnO‐eugenol cement, gave smaller initial release of formaldehyde, formocresol and cresol compared with the release from ZnO, but more prolonged diffusion. A higher initial release of formaldehyde was obtained when the formocresol was incorporated in ZnO alone compared with ZnO‐eugenol cement or Pha

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1978.tb00626.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

abstract—The aim of the study was to assess the state of the pulp of primary teeth successfully treated by formocresol pulpotomy. Nineteen teeth, all of them with clinically and radiographically successful treatments, were extracted 3–24 months after treatment. The pulpal condition had changed in all the teeth. Inflammatory reaction or necrosis was observed in all teeth. Dentinal resorption followed by apposition of hard tissue were common findings. In the teeth with vital tissue only in the apical area, the tissue had minor or no signs of inflammation. Microorganisms could be demonstrated in the necrotic tissue in one tooth. The wide range of pulpal conditions observed indicated that there was no typical tissue reaction to formocresol even though treatment was clinically successful. The present study confirms that the formocresol method should be regarded only as a means to keep primary teeth with pulp exposures functioning for a limited period of t

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1978.tb00627.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

abstract—The prognosis for pulpotomy of primary molars with calcium hydroxide as wound dressing was evaluated clinically and radiographically. Thirty‐three primary mandibular molars were amputated under the following conditions: (1) chronic coronal pulpitis, (2) the amputation was done with diamond instruments and a high‐speed machine under aseptic conditions, and (3) application of calcium hydroxide in contact with the wound surface. After 1 year the treatment was regarded as successful for 22 of the teeth (67%); II teeth showed internal dentin resorption. After 2 years the frequency of success, allowing for drop‐out, was 5996. Internal dentin resorption was seen in 14 root canals; in 10 of them within the first 6 months. A histologic study of nine root pulps with internal dentin resorption revealed an extra‐pulpal blood clot on the wound surfac

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1978.tb00628.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

abstract—Histochemical investigations on the mandibular condyle were performed on 72 human embryos and fetuses of crown‐rump lengths (CRL) ranging from 26 to 186 mm, representing skeletal maturity indices expressed in CNO values (CNO=composite number of ossified bones in the hand and foot) ranging from 0–0 to 19–12. The development of the mandibular condyle is described according to morphology and to histochemical reactions for glyicosaminoglucuronoglycans, collagen, glycogen, alkaline and acid phosphatase, and nonspecific AS esterase. The development is described for (1) the bony component of the mandibular condyle, (2) the condylar cartilage, and (3) the fibrous cover of the mandibular condyle. For each tissue component, maturation steps are set up and included in the total evaluation of the condylar maturity stages. The developmental sequence set up on the basis of the morphologic and histochemical findings was followed by all condyles investigated. From this it may be presumed that the developmental sequence in human mandibular condylar components is constant during the former half of the prenatal period. The material available did not justify a description of skeletal development in the mandibular condyle as a function of fetal size, CRL, or skeletal maturity in the hand a

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1978.tb00629.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

abstract—Mercury vapor levels associated with grinding amalgam models and mulling amalgams in the palm of the hand following trituration have been measured in a dental laboratory in inhalation position. The threshold limit value of airborne mercury of 0.05 mg/m3was essentially exceeded in the grinding procedure of amalgam. Levels in excess of seven times this value were recorded. During mulling the mercury vapor level fluctuated around the threshold limit value. The mean mercury concentrations did not essentially exceed the threshold limit valu

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1978.tb00630.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY