Periodontics: current concepts and emerging trends.
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Guided Tissue Regeneration, Periodontal↗
Biomedical subjects
J Meyle
Publications and source records attributed to J Meyle.
Interleukin-4 gene polymorphisms in Japanese and Caucasian patients with aggressive periodontitis.
OBJECTIVES: Recently, interleukin (IL) 4 gene polymorphisms have been analyzed in association with periodontitis. Genetic differences between Caucasian and Japanese patients with periodontitis have previously been detected. The aim of the present study was to analyze IL-4 genotypes in Caucasian and Japanese patients with aggressive periodontitis (AgP). MATERIAL AND METHODS: One hundred and twenty-four subjects were included in the study, 31 Japanese and 30 Caucasian patients with generalized AgP, plus 30 Japanese and 33 Caucasian healthy controls. IL-4 polymorphisms were determined by polymerase chain reaction. A logistic regression was used to investigate the possible association of the genotypes with the disease in both populations. Odds ratio (OR) estimates were analyzed for allele frequencies. RESULTS: No significant association of IL-4 polymorphisms with the risk of AgP was determined in either population. However, the allele frequencies showed different results between populations. The carriage of the polymorphism in intron 2 was higher in Caucasian patients compared with controls (OR: 2.0, 95% confidence interval: [1.0;4.2]. Furthermore, the frequency of the IL-4 promoter/intron 2 composite genotype (PP+/IP+) in patients and controls, respectively, was found to be approximately 25% and 60% higher in the Japanese population than in the Caucasian population. CONCLUSION: There was no evidence of an association of IL-4 genotypes and AgP in either population, although the frequencies of the IL-4 genotypes in the Japanese and the Caucasians were different.
Adult↗
Analysis of genetic polymorphisms at the interleukin-10 loci in aggressive and chronic periodontitis.
BACKGROUND/AIMS: Different cytokine genotypes have been described in periodontal disease. The aim of the present study was to investigate the genetic association of two previously described interleukin-10 (IL-10) polymorphisms in patients with aggressive (AP) and chronic periodontitis (CP) and to investigate possible associations with clinical manifestations. METHODS: Based on clinical parameters and radiographs, 23 patients with CP and 18 patients with AP were included in the study. Additionally, 21 age-matched healthy subjects served as a control group. Genomic DNA was isolated from whole blood samples and the IL-10 promoter sequences from positions - 597 to - 824 were amplified by polymerase chain reaction (PCR). Polymorphisms were detected by restriction-enzyme cleavage. The A and C alleles at the - 597 position were associated with the T and C alleles at the - 824 position, respectively. Fisher's exact test was used for the statistical analysis. RESULTS: No significant differences were observed in the allele frequencies between controls and AP patients (p = 0.70) or CP patients (p = 0.43), although the previously reported association between allele A at position - 597 and allele T at position - 824 was observed in our population. CONCLUSION: We conclude that the investigated polymorphisms are not associated with periodontal disease.
Acute Disease↗
Interleukin-4 polymorphisms in early onset periodontitis.
BACKGROUND, AIMS: Periodontitis is the result of a complex interplay between oral bacteria and the host response, often modulated by behavioral factors. Early-onset periodontitis (EOP) is defined by the age of onset, the distribution of lesions and specific microbial pathogens. METHOD: Studies in twins suggested a genetic contribution to the pathogenesis of periodontitis. EOP heritable factors may be related to immune mechanisms which could enhance the pathogenic potential of plaque bacteria in susceptible individuals. Among others, Interleukin 4 (IL-4) is a potent cytokine in the immune response and is a potent down regulator of macrophage function. In the present study, we report a specific genotype of the IL-4 gene, which was detected by specific primers and PCR analysis. RESULTS: In the EOP-group 27.8% were IL-4 promotor- and intron polymorphism positive (PP+ and IP+). None of the age-matched healthy controls or patients with adult periodontitis (n=25) carried the markers. Moreover, serum IL-4 levels of PP+ and IP+ patients were below the detection limit and significantly different (p<0.01) from the IL-4 concentrations of healthy controls and PP- and IP- patients.
Adult↗
Concentration of interleukin-1beta and neutrophil elastase activity in gingival crevicular fluid during experimental gingivitis.
BACKGROUND/AIM: The aim of the present study was to measure interleukin-1beta concentrations and neutrophil elastase activity in gingival crevicular fluid (GCF) during experimental gingivitis in humans. MATERIAL AND METHODS: 12 healthy young men participated. After prophylaxis, they performed optimal hygiene to reach plaque and gingivitis indices of or approaching zero. All oral hygiene measures were then ceased for a period of 18 days. The Quigley-Hein plaque index (PLI) and Saxer & Mühlemann papillary bleeding index (PBI) were assessed. GCF samples were taken from the mesiobuccal site of two contralateral teeth in the upper jaw by means of periopapers at baseline and on days 3, 7, 14 and 18. After measuring the gingival crevicular fluid volume (GCFV) with the Periotron 8000, the samples were analyzed in our laboratory for the detection of IL-1beta concentration by ELISA. RESULTS: PLI and PBI showed a reduction prior to baseline reaching almost zero, both increasing from day 0 to day 18 (PLI=from 0.1 to 2.9, PBI=from 0 to 2.0). IL-1beta concentration increased from 229.25 ng/ml (day 0) to 526.13 ng/ml (day 18). Clinical data and IL-1beta concentrations were correlated with elastase activity (EA). No significant correlation could be demonstrated between the clinical parameters assessed and IL-1beta or EA (Spearman rank correlation coefficient). A correlation between GCFV and PBI from day 0 to day 18 could be demonstrated. CONCLUSION: Overall, both IL-1beta and EA showed an increase from baseline throughout the whole study.
Adult↗
Microassay for the detection of elastase activity in the gingival crevice.
BACKGROUND, AIMS: A new microassay for the detection of elastase activity (EA) in gingival crevicular fluid (GCF) has been established. GCF was collected with Periopaper strips and quantified in a Periotron. METHODS: Enzyme activity was measured in a microtiter plate reader, using a fluorometric assay. To ensure quality and precision of the assay, recovery rates were determined at different activities with a recovery of >90%. In a 2nd step, stability of the enzyme was investigated during storage at room temperature, +4 degrees C, -22 degrees C, -88 degrees C. GCF samples retained elastase activity of almost 100% after a storage of 3 days at -22 degrees C. In a group of 12 healthy volunteers, elastase activity was assayed throughout an 18 day experimental gingivitis protocol. RESULTS: Median activity increased from 481 microU/microl at baseline to 1444 microU/microl at day 18, which was accompanied by the development of the signs of gingivitis. The increase of EA during the experimental phase of the study was highly significant (p<0.001) and correlated well with the increasing severity of gingivitis. CONCLUSION: The data suggest that elastase activity in GCF is an excellent quantitative measure of gingival inflammation.
Adult↗
Influences of systemic diseases on periodontitis in children and adolescents.
Systemic diseases affecting the host response as primary immunodeficiencies or secondary defects caused by lack of nutrients or changes in the local tissues are very often accompanied by early-onset prepubertal periodontitis. Local treatment in combination with systemic antibiotics may in milder forms improve the situation, but in many cases the success is questionable and premature loss of teeth occurs. Since the genetic basis of many of the diseases has been identified, future developments permit the correction of at least some of these defects by gene therapy.
Acquired Immunodeficiency Syndrome↗
A clinical evaluation of some factors affecting image quality in panoramic radiography.
AIM: To evaluate the suitability of panoramic radiographs obtained with two different machines for clinical use. MATERIAL AND METHODS: Three observers assessed 111 pairs of panoramic radiographs taken with the Scanora (Soredex, Orion Corp., Helsinki, Finland) programme 001, and the Orthophos Plus (Sirona, Bensheim, Germany), programme P1 respectively, for visualisation of seven anatomical structures on each side, on a 5-point scale where 1 = very good. The median values were computed and a descriptive analysis performed. Interrater and intrarater agreement were expressed as weighted kappa. RESULTS: The median values of both Scanora and Orthophos radiographs were the same, scoring 2. The intra- and inter-observer agreement was generally poor and similar for both machines. CONCLUSIONS: The two panoramic machines were both given good ratings for evaluation of anatomical structures. The differences were very small and suggest that both machines are suitable for clinical use.
Alveolar Process↗
Regression coefficient analysis of neutrophil chemotaxis in periodontitis.
Micropore-filter techniques have been widely used to assess motility and chemotaxis of neutrophils. In some cases the results were impaired by inadequate methods of evaluation and failures of the test system. For clinical purposes the mode of test evaluation should be able to differentiate between failures of the test system (false-negative) and real functional defects (true-negative). A new method has been developed to check parallel assays for homogeneity. Based on earlier procedures this type of evaluation uses the comparison of regression coefficients to identify false-negative test results within the cell population of an individual. The newly developed method was used to study the chemotactic response in a group of 49 patients and 22 healthy volunteers. Intraclass correlation coefficients of the regression coefficient analysis and the leukotactic index were calculated and compared. It could be demonstrated that the regression coefficient analysis had the same sensitivity as the leukotactic index. Slight variations in the cell counts at a single plane of the chemotactic filter affecting the leukotactic index by 18% had no measurable influence on the calculated regression coefficient.
Adolescent↗
Transepithelial electrical resistance and tight junctions of human gingival keratinocytes.
Human gingival keratinocytes (HGKs) were studied by means of freeze-fracture technique, conventional electron microscopy and the transepithelial electrical resistance for the investigation of intercellular contacts. For the purpose of comparison, MDCK cells and HaCat cells were also included. An unexpected finding was the presence of tight junctions in the HGKs. In vivo the tight junctions, which were of low complexity and P-face-associated, were co-distributed with desmosomes; in one case, the strands ran directly through desmosomal plaques. Where tight junctions and desmosomes occurred together, no gap junctions were seen. In contrast, where no tight junctions were present, gap junctions and desmosomes were co-localized. However, the unfavourable fracture planes through the tissue did not allow a clearcut allocation of gap junction/tight junction occurrence to certain strata. In vitro, HGKs also expressed tight junctions which formed networks of low complexity and high P-face association. Whereas desmosomes were highly expressed, gap junctions were not observed in cultured keratinocytes. Transepithelial electrical resistances (TEER) of cultured HGKs were higher than the values in low resistance-MDCK cells and HaCat cells but considerably lower than the values in high resistance MDCK cells, supporting the fundamental correlation between tight junction morphology and TEER. The results with this cell culture model of the human gingiva provide some valuable information about in vitro differentation and concommittent changes in cellular contacts of human gingival keratinocytes.
Cell Line↗
Genetic studies of syndromes with severe periodontitis and palmoplantar hyperkeratosis.
The Papillon-Lefèvre and Haim Munk syndromes are characterized by the presence of both palmoplantar hyperkeratosis (PPK) and severe early onset periodontitis. It is the early onset periodontal disease component that distinguishes these from other more common forms of PPK. It has been proposed that the periodontal disease component may be a casual association in individuals with PPK. Genetic syndromes with palmoplantar keratosis and severe ealry onset periodontitis may be due to specific bacterial infections in individuals with PPK. Recently, keratin gene mutations have been identified in several conditions typified by palmoplantar keratosis. The present study sought to test the hypothesis that a keratin gene defect similar to those previously identified in other PPK conditions is responsible for the Haim Munk and the Papillon. Lefèvre syndromes. We have performed genetic linkage studies to test for linkage between polymorphic DNA loci within 2 cytokeratin gene families and the disease phenotype in Haim Munk syndrome and Papillon-Lefèvre syndrome. Families with individuals segregating for the Haim Munk syndrome and the Papillon-Lefèvre syndrome were examined to determine disease status, and genotyped for microsatellite DNA markers closely linked to the acidic (type I) and the basic (type II) cytokeratin genes on chromosomes 12 and 17. Genotype data were evaluated for microsatellite allele homozygosity in affected individuals. Results of these preliminary genetic studies suggest that the gene defect in Haim Munk syndrome is not due to a gene defect in either the type I or the type II keratin gene clusters. These findings suggest that Haim Munk syndrome may be genetically distinct from other more common forms of PPK that have been linked to the cytokeratin gene families, and suggest that mutations in genes other than keratin genes are responsible. Additional family studies are needed to confirm these preliminary findings.
Adult↗
Influence of the surface structure of titanium materials on the adhesion of fibroblasts.
Of utmost importance for the successful use of an implant is a good adhesion of the surrounding tissue to the biomaterial. In addition to the surface composition of the implant, the surface topography also influences the properties of the adherent cells. The aim of this investigation was thus to study the influence of the surface structure of the substrate on the formation of focal contacts and on the orientation of cultivated gingival fibroblasts by means of fluorescence microscopy. A further goal was to determine the effect of the material composition on the cell shape, on the assumption that in each case a lengthening of the cells can be expected to provide a more favourable adhesion behaviour than a spherical cell shape. In order to describe the shape of the cell, a shape factor was defined which was calculated from the area covered by the cells and from their circumference. To determine the influence of the surface structure, substrate platelets of cp-titanium, TiAl6V4 and TiTa30 were ground. Onto these specimens human gingival fibroblasts of the 5th to 7th passages were cultivated. After a culture time of two days the cells were fixed and stained. The number of orientated cells was determined as a function of the surface roughness of the substrate. The number of orientated cells was shown to increase---independent of the material---with increasing roughness of the ground substrate. On a polished surface the number of orientated cells was 11% (average peak-to-valley height 0.04 microns); at a peak-to-valley height of 1.36 microns the number of orientated cells increased to 72%. It could be observed that the orientated cells had a higher density of focal contacts where they were in contact with the edges of the grinding grooves. In order to determine the effect of the surface composition, gingival fibroblasts were cultured for 14 d on polished substrate specimens of cp-titanium, TiAl6V4 and TiTa30 and examined for differences in shape. The cells grown on cp-titanium and on TiTa30 had shape factors of 1.76 and 1.58 respectively, whereas those grown on TiAl6V4 had a shape factor of 0.93. The unfavourable spherical shape of the fibroblasts (resulting in a poor adhesion) grown on TiAl6V4 after a culture period of 14 d may be the result of a locally increased vanadium concentration in the substrate, with an accompanying increase in the release of toxic vanadium ions.
Alloys↗
Partial expression of the Papillon-Lefèvre syndrome in 2 unrelated families.
The Papillon-Lefèvre syndrome (PLS) is a rare, autosomal recessive trait that is characterized by palmar plantar keratosis (PPK) and severe, early onset periodontitis, affecting both deciduous and permanent dentitions. The clinical presentation of PLS is variable; the disease occurs so infrequently as to limit clinical cases for study. The exception is a few families with extensive consanguinity in which numerous cases occur. Of particular interest to mapping the genetic origin of the syndrome is the co-expression of the major traits of hyperkeratosis and periodontitis, and their severity. In this paper, we report 2 families with multiple affected individuals from geographically remote areas. A large extended family, from the Cochin region of India, currently residing in Israel, in which there is documented consanguinity and a family from the southwest region of Germany. In each family, 1 individual presents with hyperkeratotic lesions with the complete absence of periodontal lesions. Further, the difference in severity of the hyperkeratotic lesions between families is marked, and one sibling in the German family expressed rapid, early onset periodontitis in the absence of PPK. The genetic nature and penetrance of the genetic defect are discussed.
Adult↗
Effects of various hygiene procedures on the surface characteristics of titanium abutments.
The use of cleaning instruments on titanium implants may cause undesired surface alterations. In a qualitative and quantitative assessment of these alterations, 5 titanium implant abutments were treated with a steel curet, a prototype pure titanium curet, an air abrasive polishing system, and an ultrasonic system. Custom-made polymer templates, used to secure the curet to a vertical guide bar and a spring scale to maintain a constant instrument pressure, guaranteed a standardized procedure and reproducible results. The ultrasonic and the air abrasive polishing method were also standardized. Evaluation by scanning electron microscopy (SEM) revealed surface alterations for all instruments and systems except the plastic curet, which did not roughen the surface at all. The confocal laser-scanning microscope allows a 3-dimensional reproduction of these surface alterations and their direct measurement. The profilometric tracing was not sensitive enough to register the minor effects caused by the titanium curet and the air abrasive polishing system. Dimensions of the resulting surface microstructure could be determined with the laser-scanning microscope. Since the influence of such surface defects on the peri-implant tissue reaction is unpredictable, the titanium curet and the air abrasive system can only be recommended with restrictions. The steel curet and the ultrasonic system proved to be totally unsuitable for cleaning titanium implants.
Curettage↗
Radiographic imaging of the hard palate and maxillary third molars with spiral tomography: a novel technique of patient positioning.
The Scanora spiral tomography system can be used to solve a range of imaging problems in the maxillofacial region. However, the system has no specific programs for imaging bony lesions of the hard palate or medially and cranially displaced maxillary third molars. New patient-positioning techniques were therefore developed on the basis of phantom radiographs, and their successful application in patients is presented. With the novel techniques, good radiographic representations of the hard and soft palates in the posteroanterior and lateral projections and of maxillary third molars were achieved.
Female↗
Variation in contact guidance by human cells on a microstructured surface.
Contact guidance induced by the surface topography of the underlying substratum influences the interaction of tissue cells with implanted material. It was the aim of this study to compare the reaction of different human cells on the same surface microtexture. After staining with fluoresceinediacetate, the orientation of human fibroblasts, gingival keratinocytes, neutrophils, monocytes, and macrophages on a regular surface microstructure of 1 microns pitch and 1 microns depth was analyzed by fluorescence microscopy. Contact guidance could not be observed in the experiments with keratinocytes and neutrophils, but 100% of the fibroblasts and approximately 20% of the monocytes and macrophages reacted with alignment. After 2 h some of the macrophages extended long dendritic cellular processes parallel to the long axis of the microstructures.
Cell Physiological Phenomena↗
Chemotactic activity of substances derived from antibody-loaded tumor cells on granulocytes.
Chemotactic activity of granulocytes attracted by tumor cells loaded either with anti-ganglioside monoclonal antibodies (mAb) or with antibody-glucose oxidase conjugates (mAb-GO) was investigated. The melanoma cell line SK-Mel-28 which expresses the ganglioside GD3 at high density as well as the neuroectodermal cell line SK-N-LO which expresses GD2 were used for the experiments. In the presence of 50% human AB-serum, antibody-loaded tumor cells induced chemotactic activity on granulocytes, probably due to the generation of C3a/C5a which could be detected in serum incubated with anti-GD3 loaded SK-Mel-28 cells. Both compounds could also be detected in vivo in the plasma of patients suffering from neuroblastoma during therapy with anti-GD2 antibodies. In another set of experiments mAb-GO conjugates generating high amounts of H2O2 in the presence of glucose were bound to these tumor cells. A significant lipid peroxidation could be observed in the simultaneous presence of iron and ascorbate. The lipid peroxidation products were measured as thiobarbituric acid-reactive substances (TBARS) and were also shown to induce chemotactic effects on granulocytes.
ABO Blood-Group System↗
Leukocyte adhesion deficiency and prepubertal periodontitis.
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Aggressive Periodontitis↗