摘要:

The aim of this study was to investigate whether induced fatigue of the masticatory muscles had any influence on the head posture, and whether this influence is related to the rest position and the movement characteristics of the mandible. The sample consisted of 13 female individuals, aged 23–34 yr. For the evaluation of possible changes in the natural cranio‐vertical head posture, standardized facial profile photographs were used. Photographs were also used for the study of the facial characteristics. The freeway space and the opening and closing velocity of the mandibular displacement, as well as the duration of the masticatory cycles, were monitored with an optoelectronic method. A controlled dynamic fatigue was induced by a specially constructed spring‐loaded device placed in the premolar region. No significant changes in the mean cranio‐vertical postural position of the head were found during the various recording stages, while the freeway space was found to increase significantly after the fatigue test. No significant differences were observed concerning the average values of the mandibular movement characteristics. The analysis of the associations between the individual changes showed an increase in the freeway space after the fatigue test in the subjects which exhibited an increase in the duration of the masticatory cycle in that period. No significant associations could be found between the changes in the head posture and the mandibular movement characteristics. Also, no significant correlation could be found between the facial type of the subjects and the variables

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1995.tb00013.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

S‐adenosylmethionine decarboxylase (AdoMetDC), one of three key enzymes in polyamine biosynthesis, is present in minute concentrations in adult tissues, whereas increased AdoMetDC activity occurs in conjunction with differentiation and growth. The occurrence of AdoMetDC in tissues has earlier been studied by biochemical technique only. In this work, an antiserum against recombinant human AdoMetDC was used to investigate the localization of the enzyme in different mouse tissues. In all tissues studied, immunolabeling was seen in cytoplasm, while cell nuclei were negative. In the kidney, AdoMetDC immunoreactivity was confined to the inner part of the cortex; the outer part of the cortex and the medulla displayed only a weak AdoMetDC immunoreaction. In the cortex, renal tubules were strongly reactive, while renal corpuscules were weakly immunolabeled. In developing teeth, AdoMetDC immunoreactivity displayed a gradient of distribution, the immunolabeling intensity being increased from the cervical region to the tip of the cusps. In the incisor, post‐secretory ameloblasts were strongly labeled. In the oral mucosa, epithelial cells demonstrated stronger immunolabeling than did cells of the subjacent connective tissue. As for muscle cells, immunoreactive material was confined to the periphery of the fibers.In vitro, treatment with DL‐α‐difluoromethylornithine (DFMO) or methylglyoxal bis‐(guanylhydrazone) (MGBG) led to an increase in AdoMetDC. It can be concluded that antibodies to recombinant human AdoMetDC provide a tool for the immunohistochemical localization of AdoMetDC, and that the distribution of the enzyme in the tissues studied gives further support to the importance of polyamines in the development and functions of th

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1995.tb00014.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Neutral salt extracts of 14 specimens of jaw cysts were prepared. Histopathological analysis showed that the specimens consisted of 6 radicular cysts, 6 dentigerous cysts, 1 residual cyst, and 1 odontogenic keratocyst. One periapical granuloma, J dental follicle and a sample of clinically healthy oral mucosa were similarly processed and used as controls. Measurement of collagenase activity by monitoring the formation of specific degradation products of type I and II collagen in solution by SDS‐PAGE demonstrated that all the cyst extracts contained collagenase, some of which was endogenously activated. Cyst wall collagenase preferably degraded type 1 over type II collagen, which suggests that the degradation was due to MMP‐1 (matrix metalloproteinase‐1) rather than the MMP‐8 type. This was further supported by the doxyeycline‐inhibition profile of cyst collagenase, which was similar to that of MMP‐1. Part of the cyst wall collagenase was in latent proenzyme form and probably derived, at least in part, from the newly synthesized intracellular collagenase pool. Latent cyst collagenase was efficiently activated with phenylmercuric chloride and to a lesser extent by gold (I) thioglucose and NaOCl, Western‐blotting, using specific antibodies against collagenase from human polymorphonuclear neutrophilic leukocytes (MMP‐8) and from fibroblasts (MMP‐1), revealed a typical 55/45 kDa doublet: also MMP‐8 in the latent 80 kDa form and fragmented to 65 kDa active species were found. These results suggest the presence of MMP‐1 and, to a lesser extent. MMP‐8 type collagenase in the cyst wall. The presence of partially activated interstitial collagenases in the cyst wall may contribute to cyst wall remodeling and may thus, in par

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1995.tb00015.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

The aim of the present study was to examine to what extent pH affects human fibroblast repopulation of an experimental woundin vitrolaying special emphasis on cell migration, DNA synthesis, and alterations in cell morphology. Wounds were simulatedin vitroby partially scraping off monolayers of human embryonic diploid lung fibroblast and human periodontal ligament fibroblast‐like cells respectively. The wounded monolayers were cultured at pHs ranging from 7.2 to 8.4. The experiments were evaluated by autoradiography as well as light and scanning electron microscopic techniques. A significant, approximately linear, decrease was noted both in cell migration into and DNA synthesis in the experimental wounds as a result of pH increase. The surviving cells in the wounds showed cytoplasmatic vacuoles and blebbing at pH levels above 7.8. Clinical implications of these results for endodontic calcium hydroxide treatment are that hydroxyl ions, diffusing through root dentin, may interfere with vital cell functions necessary for healing on the root surfac

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1995.tb00016.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

The influence of systemic doxycycline on the number of surgically induced osteoclasts was studied in young albino rats. Forty Wistar rats, aged 50 d at the start of the experiments, were randomly assigned to two groups. The experimental group (20 animals) received 0.5 mg/ml doxycycline added to the drinking water. Mucoperiosteal flaps were raised on the palatal aspect of left maxillary molars in all animals. Two rats from each group were killed daily during a postoperative period of 10 d, and specimens were prepared for light microscopy. Cellular counts in serial sections of crestal bone indicated a delay of initial surface colonization of 2 d. Statistical analysis revealed a smaller number of osteoclasts in doxycyciine‐treated animals as compared to control rats. In conclusion, systemic doxycycline suppresses recruitment of osteoclasts following surger

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1995.tb00017.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

This investigation was designed to study the formation of secondary dentin in permanent teeth of young cats after denervation. In eight animals, cervical dentin was exposed bilaterally in the mandibular canines, 7–10 d after unilateral resection of the inferior alveolar nerve. The observation intervals were 30 d, 90 d and 180 d, after which histological examination of dentin was performed. In order to verify the loss and regeneration of pulpal innervation and an intact blood supply, blood flow responses to electrical stimulation of the tooth and to i.v. injections of substance P (SP) were recorded by laser Doppler flowmetry before and at 7–10 d after denervation, at the end of the experiments, and at predetermined intermediate intervals. SP‐induced vase‐dilation was significantly enhanced at 1 wk and 30 d postoperatively and was normalized to control values at 90 and 180 d. Vasodilation in response to electrical tooth stimulation, which was absent after denervation, reappeared after 90 d in two of four cats. There was no irregular dentin formation under the exposed dentin at any time in denervated or control teeth. Formation of regular secondary dentin appeared to be enhanced on the denervated side at 30 d and 90 d postoperatively, whereas at 180 d there was no difference between sides. The results indicate that intradental nerves influence secondary dentin formation in feline permanen

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1995.tb00018.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

To investigate the effects of a high sucrose diet and xylitol on secondary dentinogenesis and dentinal caries, a part of the sucrose in a high‐cariogenic diet was replaced by xylitol. Fifty‐four 3‐wk‐old Wistar rats were labeled with tetracycline and divided into groups. One group received a high sucrose diet (43% sucrose). In two other groups 5% and 20% of the sucrose was replaced by xylitol. A control group received non‐cariogenic food. Six weeks later the mandibles were sectioned sagittally. Schiff staining was used to classify the caries, and the areas of dentin formed during the experiment and dentinal caries in first and second molars were measured planimetrically. The high sucrose diet reduced dentin formation of the molars, and this reduction was further increased by xylitol. Caries initiation and dentinal caries progression were significantly reduced by 20% xylitol, whereas only a slight reduction in caries progression was observed with 5% xylitol. Also, a negative correlation between the dentin formation and dentinal caries progression was observed in the high sucrose and 5% xylitol groups. In conclusion, xylitol together with high sucrose reduced dentin formation and dentinal caries progression, and the effect was dose

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1995.tb00019.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

A double‐blind, randomized, 2‐wk experimental gingivitis clinical trial with cross‐over design in 14 dental students was conducted in order to study the efficacy and safety of delmopinol hydrochloride solution (2 rug/ml), used with no other oral hygiene procedures, in comparison with placebo. Plaque formation was measured by the Quigley&HeinPlaque Index and gingivitis was assessed by bleeding on probing according to Mühlemann&Son. Rinsing with delmopinol resulted in lower plaque scores compared to placebo. The development of gingivitis was weak during the 2‐wk test periods, and thus no conclusive results were obtained. As in previous studies, the most frequent adverse event when rinsing with delmopinol was a transient anaesthetic sensation in the oral mucosa. The results showed that rinsing with delmopinol hydrochloride solution (2 mg/ml) for 60 s twice daily with no other oral hygiene procedures led to less plaque formation than rinsing with placebo. This study also showed good tolerance and acceptability of mouthrinsing with de

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1995.tb00020.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Reports indicate that oil/water mouthrinses with an aqueous phase containing an antibacterial agent, reduce the amount of volatile bacterial products in expiration air compared with aqueous mouthrinses. These systems have not, however, been tested concerning antiplaque activity. The aim of the present study was to examine the plaque‐inhibiting effect of a mouthrinse with an aqueous phase containing 0.2% chlorhexidine (CHX) and an oily phase (soya oil) containing 0.3% triclosan. A test panel rinsed with the mouthrinses twice daily for 4 d. The mouthrinse containing CHX and triclosan in two phases was significantly better than the negative control (water). However, it was not as effective as the rinse consisting of an aqueous phase with chlorhexidine combined with an oily phase without triclosan. A two‐phase mouthrinse with soya oil containing 0.3% triclosan was not superior to soya oil alone, and the combination of CHX and triclosan in a two‐phase rinse was not as effective as 0.1% CHX alone in water. No beneficial effect on plaque inhibition could thus be found by using a two‐phase system with two different antibacterial agents (one water soluble and one lipid soluble). Soya oil without triclosan rendered higher plaque inhibition than the control, presumably due to formation of a hydrophobic layer on the tooth s

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1995.tb00021.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

The aim of the present study was to study the effect of fluoride gel treatment on fluoride release and inhibition of acid production ofStreptococcus mutansby different glass ionomer cements. Test slabs of four glass ionomer materials were fitted into the bottom of a test tube. A layer ofS. mutanscells was centrifuged onto the test slabs, and the specimens were incubated for 4 h in 1.7% sucrose solution. Incubations were made using fresh, aged (29 d), aged and F‐treated (1.25% F‐gel), and aged, F‐treated and aged samples (n= 15 per group). After each incubation, pH and F contents of the fluid phase were determined. The freshly mixed glass ionomer samples released large amounts of fluoride, and the pH fall in the fluid phase was significantly inhibited. For aged samples, the fluoride release decreased strongly and no inhibitory effect on acid production byS. mutanswas seen. After application of fluoride gel, fluoride release and inhibitory effect were significantly higher than initially for all glass ionomer cements. In conclusion, all glass ionomer cements were able to take up fluoride and subsequently release it, which resulted in reestablishment of their antibacterial effect. The patterns of fluoride release and antibacterial action were virtually the same for conventional and resin‐reinforced glass ionomer

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1995.tb00022.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY