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At least 19 recordsLinked to original sources
PubMed1992

Morphology of central terminations of intra-axonally stained, low-threshold mechanoreceptive primary afferent fibers from oral mucosa and periodontium in the rat.

Horseradish peroxidase (HRP) was injected intra-axonally into functionally identified primary afferent fibers within the rat spinal trigeminal tract in order to study the morphology of their central terminations. They were physiologically determined to be large, myelinated afferent fibers from periodontium or oral mucosa by means of electrical and mechanical stimulation of their receptive fields. Twenty-eight axons that innervated the periodontium of incisors and 21 axons that innervated the oral mucosa were stained for distances of 2-5 mm from the injection sites at the levels of the main sensory nucleus (Vms), spinal trigeminal nucleus and rostral cervical spinal cord. The collaterals of these primary afferent fibers formed terminal arbors in the medial or dorsomedial part of the Vms, and the oral and interpolar spinal trigeminal nuclei (Vo and Vi). In the caudal spinal trigeminal nucleus (Vc), the collaterals of one half of the periodontium afferent fibers terminated mainly in lamina V at the rostral and middle levels of Vc. On the other hand, the collaterals of the other half of the periodontium afferent fibers terminated mainly in lamina IV at the rostral level of Vc, and rostrally these terminal areas shifted to the most medial part of Vi. The collaterals of mucosa afferent fibers terminated in lamina V at the rostral level of Vc, and these terminal areas shifted gradually to laminae III and IV as the parent axons traveled more caudally. These shifts were staggered rostrocaudally according to the rostrocaudal locations of the receptive fields. The density of collaterals of periodontium afferent fibers in Vi was significantly larger than that of mucosa afferent fibers. The average size of the varicosities of periodontium afferent fibers was significantly larger than those of mucosa afferent fibers in Vo, Vi and Vc. The average number of varicosities belonging to single collaterals of slowly-adapting periodontium afferent fibers in Vi were significantly larger than those in Vo. In Vi, the average number of varicosities of single collaterals of slowly-adapting periodontium afferent fibers were significantly larger than those of rapidly-adapting periodontium afferent fibers.

Afferent Pathways↗
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↗
PubMed1991

Connective tissues of the periodontium. Research and clinical implications.

The periodontium is a complex anatomical site composed of a variety of hard and soft connective tissues. The site is subjected to enormous daily chemical and mechanical abuse, yet, for the most part remains relatively intact. Nonetheless, when breakdown does occur, the ability of the periodontium to regenerate is sometimes limited. This review considers the various components of the periodontium and how they might be involved in not only the pathology of periodontal diseases but also the various reparative and regenerative processes required during wound healing. In addition, the importance of external factors such as a variety of commonly prescribed medications on these events is discussed.

Connective Tissue↗
PubMed1992

Retained "hopeless" teeth: lack of effect periodontally-treated teeth have on the proximal periodontium of adjacent teeth 8-years later.

We previously reported the lack of effect periodontally-treated teeth prognosed "hopeless" and retained for 3.4 +/- 1.5 years have on the proximal periodontium of adjacent teeth. We now report our findings for the same group of subjects following 8.4 +/- 0.7 years of "hopeless" tooth retention. Of the 17 "hopeless" and adjacent teeth originally measured in 17 subjects, 14 of the subjects were still available for re-evaluation. Measures used to assess the periodontium of proximal surfaces of adjacent teeth included pocket depths (PD), radiographic alveolar bone level (R-BL), and periodontal ligament space width (W-PL). Treatment for the subjects consisted of surgical therapy (N = 15) and scaling and root planing (N = 2). Of the 14 subjects re-examined, 2 were eliminated due to loss of adjacent tooth reference points and 2 due to extraction of the "hopeless" tooth (N = 10). Differences in measurements (i.e., nonadjacent to "hopeless" tooth value minus adjacent to "hopeless" tooth value) were analyzed using a repeated measures ANOVA. There were no significant differences for PD (P = 0.20), R-BL (P = 0.29), or W-PL (P = 0.16). These data confirm our original findings that retained periodontally "hopeless" teeth do not significantly affect the proximal periodontium of adjacent teeth following therapy.

Alveolar Bone Loss↗
PubMed1979

[The systemic circulation and microcirculation of the periodontium vital microscopy and histological studies of incisors of rats (author's transl)].

A new classification of the angioarchitecture and blood flow is proposed in light of the results of vital microscopy studies of the windowed periodontium and gingiva of the incisors of rats. The flow pattern and the rate of blood flow are different in different vessels. The flow of blood in segmented and interconnected arterial and venous vascular sections in the alveolar and marginal periodontium corresponds to what is known as systemic circulation, whereas that in arterioles, capillaries, and venoles must be considered as belonging to what is referred to as microcirculation. Subepithelially, the microcirculatory elements constitute a nutritive, typically ordered capillary network as contrasted with the random spatial arrangement of capillary loops in the alveolar periodontium. Numerous anastomoses provide the basis for possible functional adaptation, leading to the formation of polygonal ring closures in the alveolar region. The interpretations of functional findings are based upon histotopological reexaminations.

Alveolar Process↗
PubMed1990

Periodontium and vitamin E and A in pregnancy.

The evaluation of the clinical condition of periodontium by means of the epidemiological indexes and the level of oral hygiene in two weeks intervals in the course of physiological pregnancy in 39 women in good general health revealed the maximum of inflammatory changes of periodontium in the 8th month of pregnancy with the amelioration shortly before delivery. Simultaneous follow-up of the physiological levels of vitamin E and A in four weeks intervals showed the decline of the mean levels of both vitamins in the course of the 8th month and their marked elevation shortly before delivery; therefore remains questionable, if this elevation reaching over their physiological range, contributes to the amelioration of the condition of periodontium observed at the same time.

Female↗
PubMed1992

Effect of traumatic occlusion on CGRP and SP immunoreactive nerve fibre morphology in rat molar pulp and periodontium.

Traumatic occlusion provides a trauma that affects the whole tooth and its supporting tissues. To study the effect of this trauma on CGRP and SP immunoreactive nerve morphology in pulp and periodontium, traumatic occlusion was induced in 2-months-old rats. The occlusal surface of the first maxillary molar in 30 rats were unilaterally raised 1 mm with a composite material. At different observation periods up to 30 days, the rats were transcardiacally perfused, the jaws demineralized, sectioned and processed for immunohistochemistry with the avidin-biotin-peroxidase method. Changes in nerve morphology, distribution and density in first and second molars and their supporting tissues were analyzed and compared in experimental (n = 30) and control rats (n = 14). Already after 5 days with traumatic occlusion, 22% of the experimental teeth had increased density of CGRP and SP immunoreactive nerves locally in gingiva, the periodontal ligament and the pulp, while in 15%, axonal proliferation and changed nerve morphology were found in the whole pulp (severe reaction). During a 20-day period, the pulpal nerve reactions progressed and included the whole pulp in 46% of the experimental teeth. The periodontal nerve responses were still localized only to the cervical and apical regions, and they remained local in these areas throughout the experimental periods. After 20 days the number of teeth with severe nerve changes seemed to decrease. The study shows that an unilateral change in occlusion of the first molar initiate nerve responses in the total molar dentition. In this experimental model the pulpal axons containing CGRP and SP reacted more serious to occlusal trauma than the nerves in the periodontium. The results indicate that the nerve changes in some cases might be transient.

Animals↗
PubMed1978

A continuous-flow culture system for organ culture of large explants of adult tissue: effect of oxygen tension on mouse molar periodontium.

A modified continuous-flow culture system (CFCS) was developed to maintain large explants of periodontium from adult mouse in organ culture. The culture medium was stored in a reservoir outside of the incubator, pumped via polyvinyl tubing into small glass culture chambers that were placed in the oxygenator and then collected in a waste flask. Medium was analyzed for pO2, pCO2 and pH during the culture period. Three-molar and single-molar explants of periodontium were maintained for 48 hr in the CFCS at two different pO2 ranges: 100 to 120 mm Hg and 400 to 420 mm Hg. [3H]Proline was added 24 hr prior to sacrifice. Light-microscope morphological and radioautographic observations suggested that cell viability and incorporation of [3H]proline, probably into newly synthesized protein, increased with an increase in pO2 and was related to a pO2 gradient extending from the periphery to the center of the explants.

Animals↗
PubMed1977

Study of the noncollagenous components of the periodontium.

Periodontal ligament and gingivae of bovine and porcine periodontium were analyzed for relative amounts of carbohydrates, collagen, and acid mucopolysaccharides. The sugar content was 3.6% and 3.4% of dry weight in bovine and porcine periodontal ligament, respectively. The values were lower in the gingivae being 2.34% and 2.30%, respectively. Approximately 50% of hexosamine in gingivae was present in acid mucopolysacchrides as compared to 36% in periodontal ligament. Relative to collagen there was a considerable amount of non-collagenous glycoproteins present in the periodontium as judged by carbohydrate content of the tissue.

Animals↗
PubMedDate not supplied

[Experimental research on the stresses in roots with a pin "stump" structural element and in the periodontium of the masticatory teeth using a photoelasticity method].

The photoelasticity method, that discloses the physical essence and the mechanism of the emergence of stress fields in the periodontium, was used to study the strained status of the pin 'stump' design-root-periodontium-well system in flat models with a conditioned root shape 6 perpendicular to 6; various methods of cavity preparation were used, and occlusion was exposed to different combined and solitary vertical forces. Analysis of the findings helps define the optimal methods for cavity preparation and the geometry of the pin 'stump' design from the strained deformed status of certain sites. The authors have for the first time developed a method for simulation of contact strain fields and revealed a relationship that can be calculated from simulated designs to natural ones.

Biomechanical Phenomena↗
PubMedDate not supplied

[The periodontium in experimental bruxism].

Time course of morphologic changes in periodontal tissue was studied in 42 miniature pigs with experimental bruxism. An inflammation has developed in the marginal periodontium. At first the inflammatory infiltrate was situated under the epithelial fixation to the tooth involving destruction of the epithelial fixation and formation of pockets, inflammatory infiltrate, and granulation tissue, these destructive changes involving the lower sections of the periodontium. Signs of resorption were detectable in the dental alveolus osseous wall, cement, and dentin. The changes in the periodontal tissue described above appear to result from a complex of factors developing in experimental animals with simulated bruxism.

Alveolar Process↗
PubMed1990

[Collagen as a basic element of the periodontium: immunohistochemical aspects in the human and animal. 1. Gingiva and alveolar bone].

The connective tissue (CT) is responsible for stability and function of the whole periodontium. It consists of cells, which are embedded in the extracellular matrix. Collagen plays the main role for the function of the periodontal unit. Collagen types I, III, IV, V and VI are distributed in a different pattern in all periodontal tissues, as has been here demonstrated in the gingiva and alveolar bone. Collagen type I, as a characteristic collagen type of the hard tissues, has been demonstrated by thick collagen fibers in the alveolar bone and in the gingival connective tissue. It can be differentiated from the thinner collagen type III fibers, which are localized in the gingiva (especially under the basement membrane of the epithelium) as well as only in the bone marrow stroma. The epithelium, blood vessels and nerves contain the characteristic collagen type IV in their basement membrane Filamentous (collagen type V) and microfibrillar (collagen type VI) components demonstrate different patterns of distribution, especially around the bone cells and in contrast to the other collagen types of fibrillar networks in the gingival CT. This morphological differentiation of the extracellular matrix components of the periodontium allows conclusions in the pathological and inflammatory processes as well as in the regenerative and reparative procedures.

Alveolar Process↗
PubMed1990

[Experimental studies on the transitional characteristics from touch sensation to pressure sensation in the mechanoreceptive sensation of periodontium].

Many studies have made on the physiological significance of the periodontium in relation to oral functions. But, although its importance to oral functions has been pointed out, few investigations have been carried out on the periodontal pressoreceptive information system. To help rectify this situation, as a link in investigations of soft-food textures, the author attempted to determine how a sense of pressure was perceived when loads gradually increasing from very small were applied to the tooth surface. In addition, the author attempted to clarify the way the periodontium discerns differences between initial and secondary loadings in a range of small loads between the touch sensation and the pressure sensation. Subjects were 10 males with sound, natural dentition and no disorders in mandibular functions. In order to eliminate intervention from pressoreceptors in the masticatory muscles and the mandibular joints, the upper first premolar was chosen as the test tooth. Small loads were applied in 2 directions: parallel to the first premolar vertical axis (vertical) and from the lingual to the buccal sides parallel to the occlusal plane (horizontal). For vertical loading, the mesial pit on the occlusal surface was chosen as the loading point. The middle point on the lingual surface was chosen as loading point for horizontal loading. First, loading on the tooth surface was gradually increased to obtain (1) threshold value for touch sensation; that is, minimal load required to incite a touch sensation, and (2) critical value for pressure sensation; that is, minimal load required to incite the pressure sensation subsequent to the touch sensation. Each subject was requested to press a hand switch in the moment he experienced the sensation of being touched and then again when, during increases of load, the touch sensation changed to the pressure sensation. The loading device was built into an electric strain gauge. Loads were increased gradually from 0 g to 60 g, with an increase ratio of about 10 g/sec. Loading wave and switching signal were simultaneously recorded on an oscillograph. Second, in order to determine the ability to discriminate small loads, with the same loading device, initial load was applied to the tooth. This load served as control. As soon as the load was sensed, it was removed. Then the secondary (testing) load was applied. Subjects were requested to say whether the secondary load was larger, smaller than or same as the initial one.(ABSTRACT TRUNCATED AT 400 WORDS)

Bite Force↗
PubMed1992

[The effect of quality dentistry on the condition of the periodontium].

In the periodontal prophylaxis and therapy the most important steps are the adequate professional and individual oral hygienic interventions. Several factors are interfering with our attempts to maintain good oral hygiene either on the individual or professional basis. Among these many are artificially created during dental treatments. In the first part the clinical and experimental data on the effect of bad restorations on the health of periodontium are overviewed. The literature shows that these factors per se do no cause damage to the periodontium but the altered sub- and supragingival plaque accumulation due to these factors are responsible for the pathological conditions. The author deals with the effects of the placing and quality of crown margins, the smoothness of subgingival restorations, the shape and dimensions of interproximal areas, contact surfaces, the shape of pontics and the occlusal surface on the plaque accumulation and on the practice of professional and individual oral hygiene. The periodontal prophylactic philosophy and the standards of quality dentistry as well as the basic principle of periodontal prosthodontics are also discussed.

Dental Care↗
PubMed1990

[Condition of the periodontium of medical students, Palacký University, Olomouc, by means of the CPITN Index].

The authors examined 126 medical students of the Stomatological branch, Palacký University, Olomouc--Czech and Slovaks--and 32 foreign students from developing countries. The examination under standard conditions assessed the state of the periodontium and the need of periodontological treatment. Despite the fact that in dental students we must foresee a professional attitude and knowledge of the problem, the need of periodontological cases is increasing with the extent of professional training. 10% of the 5th year dental students require a surgical operation of the periodontium. The final conclusions will be made after evaluation of the whole longitudinal study.

Adult↗
PubMed1990

[Effect of removal of calculus on periodontium by hand- and roto-pro-instruments].

It was the aim of this clinically longitudinal study to find out the consequence of the removal of calculus with hand- and roto-pro-instruments of the periodontium in 50 patients suffering from periodontal diseases. There are no clinically provable differences between the two methods of the removal of calculus. Both methods cause a statistically significant effect on the inflammatory factors of the periodontium.

Dental Calculus↗
PubMed1978

[The collection and evaluation of sulcus fluid in the juvenile periodontium].

On the collection and the evaluation of the crevicular fluid from the child's periodontium. In a methodological study on the collection of crevicular fluid, we used in 50 children with clinically healthy gingivae a method for the collection of crevicular fluid that we had modified. Small amounts of fluid could be collected in all instances, also during different periods of eruption, in the regions of deciduous and permanent anterior teeth, and in the molar region. It is planned to employ this method (after further improvements) in investigating the possible effects of changes in the crevicular fluid composition on the developmental and regenerative processes in the juvenile periodontium.

Gingival Crevicular Fluid↗
PubMed1979

Inflammatory lesions and bone resorption induced in the rat periodontium by lipoteichoic acid of Streptococcus mutans.

Severe inflammatory lesions were induced in the periodontal tissues of the rat following the intragingival injection of lipoteichoic acid (LTA) from Streptococcus mutans. There was no difference in the severity and distribution of the lesions between nonimmunized rats and animals immunized against LTA after antigenic challenge. The lesions are characterized by the occurrence of granulation tissue, massive infiltration of PMNs, abscess formation, bone resorption, and new bone formation. Deacylated LTA and saline caused relatively mild inflammation, and no significant bone resorption or new bone formation was evident. The peak response was reached after 3 intragingival infections. The mechanisms by which LTA caused the pathological alterations in the rat periodontium and the possible relations of this experimental model to periodontal disease in the human are discussed.

Animals↗