Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Periodontium”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources
PubMed2000

Targets for steroid hormone mediated actions of periodontal pathogens, cytokines and therapeutic agents: some implications on tissue turnover in the periodontium.

This review attempts to encapsulate the relevance of steroid hormone action in the periodontal tissues, during inflammation, repair and in response to current treatment modalities. Periodontal pathogens metabolise steroid hormones which could contribute to their nutritional requirements and host evasion mechanisms, by forming capsular proteins; their culture supernatants stimulate the synthesis of physiologically active steroid hormones by fibroblasts, which aid inflammatory repair. The functions of glucocorticoids, androgens, oestrogen and progesterone on connective tissue and bone, are applicable to the periodontium, being target tissue. This results in physiological effects on these tissues, during puberty, the menstrual cycle, pregnancy and the menopause. The effects of oral contraceptives and hormone replacement therapy on the periodontium have focused interest in the relationship between sex steroid hormones and periodontal health. Receptor expression and the role of the specific enzyme inhibitors, such as the anti-androgen finasteride and the anti-oestrogen tamoxifen, confirm target tissue activity for steroid hormones in the periodontium. The pro-anabolic and anti-inflammatory actions of tetracyclines, are an intriguing model for hormone mediated pathways of action. The effects of the specific alkaline phosphatase inhibitor levamisole on matrix turnover are linked to steroid hormone action, with direct implications on the healing periodontium. Drugs which contribute to gingival overgrowth are an interesting model, for explanation of an exaggerated 'scar tissue' response mediated by hormones, cytokines and a variety of enzyme systems. Cell dynamics of the periodontium plays an important role in co-ordinating the diverse interactions between steroid hormones and therapeutic agents.

Animals↗
PubMed2000

[Distribution of IL-1 beta in periodontium of experimental osteoporosis rats during orthodontic tooth movement].

OBJECTIVE: The purpose of this research is to study the expression change of IL-1 beta induced by forces in the periodontium of osteoporosis rats. METHODS: Eighteen SD rats were randomly divided into three groups: the normal controlled, the normal orthodontically controlled and the experimental group of osteoporosis. Six weeks after ovariectomy, the first molars were moved mesially by 50 g force created from elastic-thread for one week in the force loading groups. Then the rats were killed, and the 5 microns-thick mesiodistal sections of maxillary teeth, including the roots and periodontium were made. IL-1 beta were localized immunohistochemically in periodontium, and semiquantitative analysis of cellular-staining intensity was done by microphotometry. RESULTS: The IL-1 beta of periodontal ligament cells without loading force were mildly stained in the controlled group, but the staining intensity increased significantly in the periodontium of orthodontically moved teeth, and it showed more strengthened staining in the periodontium of force-loading teeth in osteoporosis rats. CONCLUSION: The results demonstrate that periodontal ligament cells respond to mechanical force by increased production of IL-1 beta, and this can be enhanced by osteoporosis. IL-1 beta is an important cytokine in the process of orthodontically periodontal remodeling.

Animals↗
PubMed1995

[Morphological changes in the periodontium from the use of different designs of metal ceramic dentures].

Morphological changes in the periodontium during the use of cermet crowns of different design were studied in experimental animals. The status of the periodontium was found to depend on the level of crown fixation with respect to gingival edge. Histological findings had show that position of a cermet crown at the level of the gingival edge does not involve appreciable changes in the periodontium, though preparation of abutment teeth with the formation of a step be considered as preferable. A subgingival position of cermet crowns leads to development of an inflammatory reaction in the periodontium, the severity of this reaction being related to a great measure to the method of the tooth preparation. If a step is formed during preparation of a tooth, the inflammatory changes are less pronounced than when there is no step formed. In the latter case the pathological changes were seen in the periodontium. The authors come to a conclusion that cermet crowns should be fixed at the level of the gingival edge. When making cermet crowns, abutment teeth should be prepared with the formation of a pericervical step.

Animals↗
PubMed1988

Drugs and the periodontium.

The periodontium and periodontal disease activity can be affected by systemic drug therapy. Many drugs can have an adverse effect on the periodontium, i.e., gingival hyperplasia. Alternatively, some drugs can modify the inflammatory and immunological responses of the periodontal tissues to bacterial plaque. The aim of this review is to evaluate the effects of drug therapy on the periodontium and periodontal disease activity, and where possible, to relate such changes to the pharmacodynamics of the drugs considered. Drugs which have been reported to affect the periodontium can be categorised as follows: anti-epileptics, immunosuppressants, corticosteroids, non-steroidal anti-inflammatory drugs and hormones. Those drugs whose pharmacodynamics are clearly established and which affect the rate of periodontal disease activity, may provide information on the mechanisms of periodontal destruction. Finally, the mechanisms of drug-induced gingival hyperplasia (overgrowth) are discussed in relationship to the drugs' pharmacodynamics and pharmacokinetics.

Animals↗
PubMed2005

Immunohistochemical identification of lymphatic vessels in the periodontium of equine cheek teeth.

Immunohistochemical detection of lymphatic capillaries was performed in the periodontium of maxillary and mandibular cheek teeth from 6 horses (aged 3-23 years). Tissue sections of the periodontium were taken at 4 different horizontal levels along the long axis of the tooth. The specimens were processed for immunoreaction with anti-Prox1, in order to distinguish lymphatic endothelium from blood vascular endothelium. Lymphatic vessels were detected in all periodontal tissues except for the dental cementum. Lymphatic capillaries were most densely distributed in the gingiva compared to other tissues of the periodontium. Lymphatic capillaries were found most consistently in samples taken from the gingival and subgingival regions in all horses examined. Within these levels, the gingiva as well as the spongiosa of the maxillary and mandibular bone had the greatest incidence of lymphatic vessels. Considering the distinct distribution of the lymphatic capillaries in the periodontium of the maxillary and mandibular cheek teeth, two complementary lymphatic drainage pathways are proposed: (1) superficial lymph drainage via the gingiva, emptying into the mandibular lymph nodes; (2) deep lymph drainage via the mandibular and maxillary spongiosa, emptying into the mandibular and retropharyngeal lymph nodes, respectively.

Animals↗
PubMed1988

Retained "hopeless" teeth. Effects on the proximal periodontium of adjacent teeth.

The retention of teeth diagnosed as periodontally "hopeless" may accelerate the destruction of the adjacent proximal periodontium. Studies determining the influence these teeth have on the health status of adjacent teeth appear nonexistent. It was the intent of this retrospective study to assess the status of the periodontium in adjacent teeth proximal to the periodontium of "hopeless" teeth. We evaluated 17 teeth, each being mesially adjacent to one "hopeless" tooth, in 17 subjects treated for periodontal disease. In each case, the "hopeless" and the adjacent teeth received the same treatment. Probing depths (P-D), radiographic alveolar bone level (R-BL) and the width of the periodontal ligament space (W-PL) were measured for both the adjacent interproximal and the nonadjacent interproximal surface for each hopeless tooth. At both pretherapy and posttherapy, there were no significant differences for any of the variables (P-D, R-BL and W-PL) for the adjacent interproximal surfaces with the nonadjacent interproximal surfaces. However, there was a significant reduction in the mean probing depth for the adjacent interproximal surfaces, pretherapy to posttherapy. No other significant changes were found in any of the other variables for either the adjacent or nonadjacent interproximal surfaces. These data suggest that teeth considered periodontally "hopeless" and retained have no effect on the proximal periodontium of adjacent teeth prior to and following therapy.

Bone Resorption↗
PubMed1995

[The pathogenesis of and treatment principles in functional overload of the periodontium].

A total of 4864 patients (2810 women and 2054 men) aged 16 to 64 with maxillofacial abnormalities and 3686 patients (2283 women and 1403 men) aged 18 to 64 with dentition defects were examined. 2624 patients aged 19 to 62 were admitted for orthodontic treatment. Experiments on 96 dogs were carried out. Pathologic changes in the periodontal tissue were detected in 3765 (77.4%) patients with maxillofacial abnormalities and in 2918 (78.8%) with dentition defects. The author considers that two major factors contribute to the pathogenesis of functional overstrain of the periodontium: change of occlusion loading of the teeth and reduced tolerance of periodontal tissues. Good results were attained in 92.7% of patients with functional overloading of the periodontium. Dog experiments demonstrated that overexercise of teeth may lead to changes in the periodontium, which are similar to tissue restructuring in orthodontic interventions. If the periodontium is weakened, an exacerbation of periodontitis develops. After stopping of functional overstrain--repair processes in the periodontal tissues of young animals, including repair of bone tissue take place.

Adolescent↗
PubMed1990

[Assessment of the periodontium condition and therapeutic needs by the CPITN index in children aged 12 years in the province of Cracow].

The aim of the study was assessment of the condition of the periodontium and therapeutic needs in children aged 12 years in the City of Cracow, Wieliczka and villages in the Province of Cracow. The total number of the studied children was 180 including 90 girls and 90 boys, 30 girls and 30 boys in each group. The number of sextants with healthy periodontium was 738, the mean value per one child was 4.10, it was higher in girls--4.24 and lower in boys--3.95. The per cent of children with healthy periodontium was 24.44%, the per cent of children with bleeding on probing was 30.56%, and with tartar--45.00%. The highest values of this parameter were found in Wieliczka children, and the lowest ones in village children. The needs for treatment of the periodontium in children aged 12 years were as follows: 75.56% required improvement of oral hygiene, 45.00% required removal of tartar. The lowest needs were in Wieliczka children--60.00%, and the highest in village children--86.67%.

Child, Preschool↗
PubMed2000

Apoptosis in the early developing periodontium of rat molars.

Development of the periodontium involves a series of complex steps that result in the formation of root dentine, cementum, bone and fibres of the ligament. These precisely controlled and timed events require the participation of the enamel organ derived epithelial cells of Hertwig's (HRS) and ectomesenchymal cells of the dental follicle. These events involve rapid turnover of the tissues and cells, including disappearance of epithelial cells of HRS. Thus, it seemed likely to us that programmed cell death (apoptosis) may play a role in the development of the periodontium. Fragments of first molars, obtained from 14- and 29-day-old rats, were fixed in glutaraldehyde-formaldehyde and processed for light and electron microscopy. For the TUNEL method for detection of apoptosis, specimens were fixed in 4% formaldehyde and embedded in paraffin. Results confirmed that epithelial cells of HRS maintain a close relationship with the forming dentine root, and that they may become trapped in the dentino-cemental junction. Some of the epithelial cells exhibited ultrastructural features which are consistent with the interpretation that they were undergoing programmed cell death, i.e. apoptosis. Periodontal fibroblast-like cells showed typical images of apoptosis and engulfed apoptotic bodies. TUNEL positive structures were present in all corresponding regions. It seems therefore that apoptosis of epithelial cells of HRS and fibroblast-like cells of the periodontal ligament constitutes an integral part of the developmental process of the tissues of the periodontium.

Aging↗
PubMed1982

Effects of orthodontic forces and anti-inflammatory drugs on the mechanical strength of the periodontium in the rat mandibular first molar.

The mechanical strength of the periodontium was examined by extracting the rat mandibular first molar from its socket in the dissected jaw following application of orthodontic forces. Rubber elastic bands of increasing sizes were inserted between the first and the second molars and following injections of anti-inflammatory drugs, hydrocortisone and indomethacin for 7 days. Marked decreases of the mean ultimate loads to extract the teeth were found following application of the orthodontic forces. Increases of the ultimate loads were found following injections of hydrocortisone and indomethacin. The distances pulled to reach the ultimate loads which seem to represent the extensibility and elasticity of the periodontium correlated closely with the ultimate loads. The orthodontic forces applied were estimated to be about 0.7 kilograms at the end of the experimental period. It was suggested that the mechanical strength of the periodontium is maintained by the organization and constitution of the periodontal collagen fibers, and by the attachment of fibers to the bone, which could be affected by orthodontic forces and by anti-inflammatory drugs.

Animals↗
PubMed1981

Autoradiography of protein turnover in subcrestal versus supracrestal fibre tracts of the developing mouse periodontium.

Eighteen-day-old C57Bl mice were injected with 5 muCi/g body weight [3H]-proline and killed at intervals of 4 h to 7 wk later. Grain counts in three fibre tracts revealed that (1) half-lives of labelled protein in the developing periodontium were much shorter than those found previously for the mature periodontium , and (2) the half-life of labelled protein in the dento-gingival region was longer than the half-lives in the trans-septal and dento-alveolar fibre tracts (half-lives: dento-alveolar = 2.5 days, trans-septal = 3.8 days; dento-gingival = 7.9 days). Eight mice were given injections of [3H]-proline on days 11, 13, 15 and 17, which encompasses the formation of the three fibre tracts, and killed 4 h, 2.5, 5 and 8 wk after the last injection. All label incorporated during the formation of the periodontium had been lost by 5 wk post-injection, showing that a stable core fibre (i.e. one which is not metabolized) was not present.

Animals↗
PubMed1982

Effect of experimental tooth movement on the mechanical strength of the periodontium in the rat mandibular first molar.

A 474 microns thick latex elastic band was inserted between the mandibular first and second molars to cause tooth movement. The mechanical strength of the periodontium was measured by extracting the first molar from the socket in the dissected jaw. From the 1st to the 4th day, the ultimate extraction loads decreased markedly, while the inter-dental spaces remained about 300 microns. About 5 min after the elastic insertion, the ultimate load was not significantly changed and the inter-dental space was 61 microns. Restoration of the mechanical strength of the periodontium occurred gradually after the removal of the band. On the 4th day, recovery was complete. Restoration of the original inter-dental space was most marked in the initial 24 h. The forces exerted on the teeth by the bands were of the order of several tens of newtons initially and became reduced to a few newtons after the tooth movements. It is suggested that decreases in the ultimate extraction loads were caused by changes in constitution of the periodontal collagen, by the disorganization of the periodontium and by the loosening of the attachment of the periodontal fibres to the bone.

Animals↗
PubMed1990

Creation of a chimaeric periodontium in the rat by isotopic tooth germ transplantation.

The purpose of this work was to develop and test a chimaeric periodontium in which it would be possible to distinguish between connective tissue cells of odontogenic and oral mucosal origin. The recombinant periodontium was created by transplanting first maxillary molar tooth germs with their follicles from 1-3-day-old hooded Lister rats into the corresponding evacuated crypts of 6-9-day-old histocompatible recipients of the same strain. Of 71 transplants, 22 had formed erupted teeth 3 weeks later, with dentogingival junctions and periodontal ligaments histologically similar to those of control teeth. The recombinant nature of the graft periodontium was confirmed by incubating tooth germs in vitro with tritiated thymidine before grafting them, and then demonstrating radiolabelled nuclei in the dentogingival junctions formed by the transplants. Labelled cells were randomly distributed within the periodontal ligament and predominantly near to the basement membrane of junctional epithelium.

Animals↗
PubMed2004

The effect of partial damage to the enamel-related periodontium combined with root resection on eruption of the rat incisor eruption.

Previous work has indicated that the enamel-related periodontium (ERP) has a role in the eruptive process of the rat lower incisor. By combining partial damage of this tissue with resection of the odontogenic organ, we examined the effect of the damage on subsequent incisor eruption. The connective tissue of the enamel-related periodontium was regenerated in less than 2 weeks, showing morphology close to normal. The injured part of the enamel organ was neither regenerated nor repaired, and a cement-like tissue, continuous with the true acellular cement, was formed on the denuded enamel. Before tooth exfoliation, the operated teeth erupted at a slower rate compared with root-resected and sham-operated incisors, probably because of the absence of a substantial part of the enamel organ due to surgical damage. As with the coronal dental follicle and the enamel organ in rat molars, the enamel-related periodontium and the enamel organ of rat incisors may have some control on their eruptive process.

Aging↗
PubMed2002

Immunolocalization of osteoclast differentiation factor in rat periodontium.

The aim here was to observe the immunohistochemical localization of osteoclast differentiation factor (ODF)/receptor activator of NF kappa B ligand (RANKL) in the rat periodontium. Rat mandibles were demineralized and embedded in paraffin, and horizontal and frontal sections were prepared for immunohistochemical analysis. In horizontal sections, immunolocalization of RANKL was marked in the distal area of the periodontium of molars in which osteoclasts appeared, due to physiological tooth drift. In frontal sections, RANKL immunoreactivity was localized on spindle-shaped mesenchymal cells around blood vessels near the bone surface in the periodontium. In addition, immunoreaction for RANKL was detected on structures that appeared to be elongated cell processes near blood vessels in frontal sections. Immunohistochemical examination for the general antigen of nerve-specific protein suggested a similarity between these structures and nerve fibres.

Acid Phosphatase↗
PubMed2003

Influence of sex hormones on the periodontium.

OBJECTIVES: Sex hormones have long been considered to play an influential role on periodontal tissues, bone turnover rate, wound healing and periodontal disease progression. The objectives of this review article are to (1) address the link between sex hormones and the periodontium, (2) analyse how these hormones influence the periodontium at different life times and (3) discuss the effects of hormone supplements/replacement on the periodontium. MATERIALS AND METHODS: Two autonomous searches were performed in English language utilizing Medline, Premedline and Pubmed as the online databases. Publications up to 2002 were selected and further reviewed. In addition, a manual search was also performed including specific related journals and books. RESULTS: It is certain that sexual hormones play a key role in periodontal disease progression and wound healing. More specifically, these effects seem to differentiate by gender as well as lifetime period. In addition, the influence of sex hormones can be minimized with good plaque control and with hormone replacement. CONCLUSION: Despite profound research linking periodontal condition with sex hormones kinetics, more definitive molecular mechanisms and therapy still remain to be determined.

Alveolar Bone Loss↗
PubMed1996

Loss of attachment in the marginal periodontium of the rat incisor under non-inflammatory conditions. Expression of alkaline phosphatase activity. Experimental Oral Biology Group.

Alkaline phosphatase (ALP) has been suggested to play a role in acellular cementum formation and maintenance of periodontal attachment. In an attempt to determine whether changes in attachment level are associated with altered expression of ALP-activity in the periodontium we induced natural loss of attachment in rats by pinning the lower incisor to the jaw bone. Previous studies have shown that this procedure results in regressive changes in the marginal periodontium without any inflammatory response. Six months after blockage of eruption the attachment level on the experimental (right) side had shifted about 700 microm in the apical direction. On the control (left) side the apical termination of the junctional epithelium had remained stationary with respect to the alveolar crest. Our observations have shown that during the first few weeks of the experiment loss of attachment is accompanied by considerable reduction of ALP-activity in the supracrestal part of the periodontium. At later time intervals, however, no distinct relation was found between apical migration of junctional epithelium and loss of ALP-activity in the supracrestal region, indicating that the two phenomena are not directly related to each other. The domain of the ALP-positive fibroblasts in the supracrestal extension of the periodontal ligament decreased in size and was replaced by ALP-negative connective tissue cells probably coming from the outer gingival domain. Since at all time intervals a distinct demarcation could be observed between the ALP-positive and ALP-negative areas, we interpret our data as indicating that ligament and gingival cells do not mix.

Alkaline Phosphatase↗
PubMed2004

Immunohistochemical localization and expression of fibromodulin in adult rat periodontium and inflamed human gingiva.

OBJECTIVE: The aim of this study was to determine the distribution and expression of fibromodulin in adult rat periodontal tissues and inflamed human gingiva. MATERIALS AND METHODS: The distribution of fibromodulin in rat molar periodontium and human gingival tissue was studied by immunohistochemistry. The expression of fibromodulin mRNA from human gingival fibroblasts, periodontal ligament fibroblasts and osteoblasts was studied by reverse transcription-polymerase chain reaction (RT-PCR). For comparative purposes, the distribution and mRNA expression of collagen types I and III, as well as the two small leucine-rich proteoglycans decorin and biglycan were also studied. RESULTS: In the adult rat periodontium, fibromodulin was distributed in the suprabasal gingival epithelium, gingival and periodontal fibroblasts as well as their surrounding extracellular matrices. Strong expression was noted in the palatal gingival tissues and the interfaces of the periodontal ligament with alveolar bone and cementum. In human gingival tissues, staining of fibromodulin was detected in the connective tissue of inflamed gingiva associated with both gingivitis and periodontitis; whereas, weak staining for this molecule was noted in healthy gingival tissues. The expression of mRNA for fibromodulin was strongest in the cultured osteoblasts. Periodontal ligament fibroblasts showed only a weak level of expression for fibromodulin mRNA. CONCLUSIONS: Fibromodulin is differentially expressed throughout the periodontium being primarily associated with collagen type I in non-mineralized sites. In addition fibromodulin showed an upregulation in inflamed gingival tissue.

Animals↗