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Biomedical subjects

A Mombelli

Publications and source records attributed to A Mombelli.

At least 73 records · Page 4Linked to original sources
PubMed1992

Antimicrobial treatment of peri-implant infections.

The purpose of this study was to investigate the possibility of antimicrobial treatment of peri-implant infections associated with a periodontitis-like subgingival microbiota. Nine partially or fully edentulous patients with titanium hollow cylinder implants were selected which showed loss of bone and probing depths > or = 5 mm on one or several implants after at least 6 months following installation. They also yielded subgingival microbial samples with > or = 10(6) CFU/ml, including > or = 20% gram-negative anaerobic bacteria. The treatment included mechanical cleaning, irrigation of all peri-implant pockets > 3 mm with 0.5% chlorhexidine and systemic antimicrobial therapy (1000 mg ornidazole for 10 consecutive days). After therapy, bleeding scores decreased immediately and, over a one-year observation period, remained significantly lower than before treatment. A significant gradual reduction in mean probing depths was detected over this one-year period; only one case showed no improvement of local probing depth. Microbiological parameters indicated an instantaneous quantitative and qualitative change following treatment. Subsequently, several of these parameters tended to shift back towards pretreatment values. In the second half of the observation period, however, this tendency was reversed, and levels significantly different from baseline were eventually established. This study demonstrated that treatment aiming at reducing the subgingival bacterial mass and suppressing the anaerobic segment had a beneficial effect in patients suffering from peri-implantitis.

Bacteria, Anaerobic↗
PubMed1992

Periodontal pathogens in the shallow pockets of immigrants from developing countries.

The aim of this study was to examine the distribution of typical periodontitis-associated microorganisms in refugees arriving from non-industrialized countries, and to relate the presence of these organisms to the periodontal condition of the subjects. Thirty males between 35-44 years of age were surveyed. Dental plaque, calculus, gingivitis, loss of attachment, and probing depths were recorded for all surfaces. A total of 90 microbiological samples were taken with paper points from mesial sites of teeth 16, 36 and 41. Microbiological test sites were grouped by probing depths and loss of attachment. Only 16.8% of all surfaces had probing depths > 3 mm, although 90.7% of surfaces had loss of attachment > 1 mm. Twenty-one sites with obvious periodontal destruction (PD > 3 mm, LA > 2 mm) showed the greatest recovery of Porphyromonas gingivalis (66.7%). However, 51 sites with minimal periodontal disease (PD < or = 3 mm, LA < 2 mm) and with no gingival recession also showed a relatively high detection frequency of P. gingivalis (34.1%). Twenty-four of these samples came from 12 patients with no pockets > 5 mm and with less than 10% of all sites yielding pockets > 3 mm. The detection frequencies of Prevotella intermedia (91.6%), Bacteroides forsythus (25.0%), Wolinella spp. (33.3%) and Actinobacillus actinomycetemcomitans (50.0%) were similar in these sites compared with periodontitis sites. Morphologically distinct isolates, from 19 individuals positive for A. actinomycetemcomitans, were serotyped by indirect immunofluorescence.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Depth-force patterns of periodontal probing. Attachment-gain in relation to probing force.

It was the purpose of this study to determine whether probing force had an influence on the amount of clinical attachment-gain assessed after treatment by scaling and rootplaning. A probing device was constructed which allowed simultaneous monitoring of probing force and probe penetration and which standardized the insertion pathway for repeated measurements. In 10 periodontal patients, 2 deep pockets were selected which were measured before and after periodontal treatment by scaling and root-planing. Depth-force plots were compared by superimposition. Depth values were determined at 5 different force levels (0.25, 0.50, 0.75, 1.00 and 1.25 N) on each plot and changes of clinical attachment levels were calculated. A significant relationship was seen between probing force and attachment level. The values obtained with 0.25 N were significantly different from the values obtained with higher forces (p less than 0.001). Slight, but non-significant differences were noted in the amount of attachment-gain obtained at the 5 force levels. At a probing force level of 0.25 N, there was 0.80 mm mean attachment gain. With 0.50 N, there was a gain of 0.70 mm; with 0.75 N the gain amounted to 0.67 mm in mean. At 1.00 N and at 1.25 N, a gain of 0.66 mm was recorded.

Adult↗
PubMed1992

Supragingival cleaning 3 times a week. The microbiological effects in moderately deep pockets.

It is generally believed that supragingival plaque control has little effect on the subgingival microflora of deep periodontal pockets. However, this may not be true for moderately deep pockets (4-5 mm), which may represent a pathological state between gingivitis and marginal periodontitis. In 6 patients with poor oral hygiene and severe gingival inflammation, 4 matched sites (1 in each quadrant), were chosen which demonstrated at least 20% spirochetes and 15% black-pigmented Gram-negative bacilli. During the first 12 weeks (phase 1), supragingival calculus was removed from the right half of the mouth and then the teeth were professionally cleaned three times a week. At the beginning of phase 2, supragingival calculus was also removed from the left quadrants and the entire mouth was subjected to the same protocol used in phase 1. At no time did patients receive oral hygiene instructions. Clinical parameters were assessed and microbiological samples were taken at 3-week intervals. Samples were submitted to darkfield microscopy and anaerobic culturing. Analysis by multiple linear regression and the Wilcoxon signed-rank test revealed significant changes in the composition of the subgingival microbiota at cleaned sites. While Gram-positive organisms increased proportionally, a number of putative periodontal pathogens, such as P. gingivalis and spirochetes decreased.

Adult↗
PubMed1992

Remodelling of periodontal tissues adjacent to sites treated according to the principles of guided tissue regeneration (GTR).

The aim of the present study was to assess the remodelling of alveolar bone adjacent to periodontal sites following therapy according to the principles of guided tissue regeneration (GTR) using computer-assisted densitometric image analysis (CADIA), and to compare the radiographic results to traditional clinical parameters. As required for digital subtraction analyses, periodically reproducible radiographs were obtained using a modification of the Rinn System and individual acrylic bite blocks for periodical identical radiographs. Ideally, a digital subtraction image from a site where absolutely no change in density had occurred would show a perfect cancellation of the structures. An average grey level value of 128 (the middle of the digitizer grey level range set by software) would show up at each pixel. Areas with grey levels < 128 in the subtraction image would indicate loss in density and grey levels > 128 would indicate increase in density. Within the subtraction images, areas were defined using the cursor to draw "regions of interest" (ROI) projected on the bony defect exposed to GTR covering the crestal bone as well as the region of potential "bonefill". The mean, median, the standard deviation and range of the grey levels of pixels within a particular ROI were calculated. Similarly sized ROI were drawn in bone areas not exposed to the GTR procedure serving as controls. The differences in the mean grey levels of all pixels within a particular ROI between the baseline, 3 and 12 months images were calculated for documentation of gain or loss in density. From 14 patients, standardized radiographs were available from baseline, 3 months and 12 months postsurgically, depicting one infraosseous defect before and after treatment according to the principles of GTR. The densitometric changes observed in these defects were compared to the clinically assessed changes measured at the site with the deepest baseline pocket depth. A mean clinical attachment gain of 2.36 mm after 3 and 3.22 mm after 12 months was measured. This was associated with a mean reduction in the PPD amounting to 3.36 mm and 3.79 mm, respectively. The changes in the level of the FGM were rather small considering the deep original mean PPD of 7.07 mm. Over the first months, a mean recession of 1.14 mm was observed which was followed by a coronal displacement of 0.43 mm. With respect to the remodelling of the alveolar bone adjacent to the defects assessed by means of CADIA, the most pronounced changes occurred when comparing the baseline to the 12 months radiographs.(ABSTRACT TRUNCATED AT 400 WORDS)

Absorptiometry, Photon↗
PubMed1992

Microbiota associated with residual clefts and neighboring teeth in patients with cleft lip, alveolus, and palate.

Twenty patients with residual clefts or pronounced soft tissue grooves, treated for uni- or bilateral cleft lip, alveolus, and palate were included in this study. Ten patients were recalled for dental prophylaxis at regular intervals, 10 patients were not. One microbiologic sample was obtained from the cleft area and two samples from a tooth adjacent to the cleft (sites adjacent and distant to the cleft). Between the recall and the nonrecall group there were notable differences in the presence of anaerobic Gram-negative organisms. Fusobacterium spp., Prevotella melaninogenica, and P. intermedia were more often found in nonrecall patients. While rarely seen in recall patients, spirochetes and motile rods were a common feature of nonrecall patients. The putative periodontal pathogens Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis were not detected in either group. The differences between the recall and the nonrecall groups were more pronounced when the respective samples from teeth were related to each other than when the samples obtained from the clefts were compared. The cleft flora was less complex irrespective of how good maintenance was and resembled the flora of teeth of well-maintained patients. Samples from clefts were never Wolinella positive, and harbored significantly less Capnocytophaga and Actinomyces viscosus than samples from dental sites.

Actinomyces viscosus↗
PubMed1992

[Do new diagnostic tests improve the differential diagnosis and therapy of periodontitis? A review].

New diagnostic tools give access to information that was previously not available by classical clinical means. This includes methods for the determination of the composition of the microbial flora or for monitoring specific reactions of host tissues to the accumulation of plaque. DNA-probes, monoclonal antibodies and enzyme assays have already been advertised and are sold to dentists. The practical value of new tests depends upon the possibility to improve the efficacy of treatment based on previously inaccessible information. This paper reviews frequently raised clinical questions, the possible answers coming from new diagnostica, and the potential impact of this knowledge on periodontal therapy.

Aggressive Periodontitis↗
PubMed1991

Black-pigmenting gram-negative bacteria in periodontal disease. I. Topographic distribution in the human dentition.

The purpose of this study was to determine the distribution of black-pigmenting Gram-negative bacteria in the dentition of periodontitis patients and to examine differences in the microbial composition of samples taken from a series of adjacent sites. Separate subgingival samples were taken from the mesial, buccal, distal and oral aspects of every tooth in 10 subjects. Thus, a total of 927 sites, 84 to 102 per patient, were scored clinically and sampled microbiologically. P. intermedia and P. melaninogenica were found in all subjects. P. gingivalis was found in 7. The organisms tended to be distributed unevenly, giving the impression of clusters of positive samples in certain areas of the dentition. 77% of all samples positive for P. gingivalis were also P. intermedia-positive. Premolars had lower frequencies and mean proportions of P. gingivalis than incisors and molars. In the premolar and molar region, frequencies and mean proportions of P. gingivalis increased with more posterior location. While frequencies indicated a similar topographic distribution of P. intermedia the mean proportions of this organism were more consistent at different locations. Based on a logistic regression model, it was estimated that the probability of detecting P. gingivalis was 34 times higher in any site which had at least 1 P. gingivalis-positive neighboring site. For P. intermedia any site with at least 1 P. intermedia-positive neighboring site had a chance 2.4 times higher of harboring the organism as well. The highest chance of detecting P. gingivalis and P. intermedia existed in deep, oral pockets of molars, which bled upon sampling.

Adult↗
PubMed1991

Black-pigmenting gram-negative bacteria in periodontal disease. II. Screening strategies for detection of P. gingivalis.

The purpose of this analysis was to evaluate the feasibility of detecting P. gingivalis using selected sites and to indicate increased proportions of this organism in periodontitis patients. In 10 patients suffering from moderate to advanced periodontal disease, separate microbiological samples were taken from the mesial, buccal, distal and oral (lingual or palatal) aspects of every tooth. This yielded a total of 927 microbiological samples, 84 to 102 per patient. Three distinct patterns of distribution and relative proportion of P. gingivalis were recognized. In one group of patients, the organism was not cultured. In a second group, few positive sites with low proportions of P. gingivalis were present. A third group of patients yielded high frequencies and proportions of P. gingivalis. The number of samples necessary to diagnose the presence of P. gingivalis at a 95% confidence level varied considerably between the three groups. In 4 patients, sampling 4 randomly selected sites was sufficient, while in the remaining 3 positive patients, 25 or more samples were required to detect the organism with equal certainty. Seven different protocols for multiple subgingival sampling were studied. When considering the number of samples needed to detect the presence of P. gingivalis and to estimate the highest proportion of this organism, selection of the deepest pocket in each quadrant was the most efficient method of sampling.

Adult↗
PubMed1990

Microbiological features of stable osseointegrated implants used as abutments for overdentures.

The microflora associated with osseointegrated implants used as abutments for overdentures was investigated in 18 edentulous patients, 2 years after implantation. 52.8% of the organisms cultured were facultatively anaerobic cocci and 17.4% were facultatively anaerobic rods, while Gram-negative anaerobic rods accounted for only 7.3%. Fusobacterium sp. and Bacteroides intermedius were both found in 8.8% of the samples. B. gingivalis and spirochetes were not found. Repeated microbiological and clinical data were collected in 9 patients during the 3rd, 4th and 5th year after implantation. No significant time trends were noted. Separate samples taken within the same patient from different sites were similar. Therefore, bacteriological independence of sites could not be assumed for the conditions investigated.

Dental Abutments↗
PubMed1990

Suspected periodontopathogens in erupting third molar sites of periodontally healthy individuals.

29 periodontally healthy subjects (11 female and 18 male) with a mean age of 24 years (range 19 to 38 years) and with partially erupted lower third molars participated in this study. 18 subjects demonstrated no signs or symptoms of acute inflammation and were without pain (group A). 5 subjects showed redness of the pericoronal tissues and experienced pain upon palpation (group B). 6 subjects suffered from acute pain and exhibited formation of pus (group C). Microbiological samples were taken from the lateral aspect of the pericoronal space using the paperpoint-method. Continuous anaerobic techniques were utilized for microbiological processing. The samples were cultivated on ETSA and on selective media and were studied by darkfield microscopy. Gram-negative anaerobic rods accounted for 27% (group A), 34% (group B) and 39% (group C) of all organisms growing on ETSA. Bacteroides intermedius was detected in 61% (group A), 80% (group B) and 83% (group C) of the samples. B. gingivalis was found in 1 sample of group A only. Fusobacterium sp. was detected in 56% (group A), 80% (group B) and 33% (group C) of the samples. Capnocytophaga were seen in 67% (group A), 20% (group B) and 50% of the samples. Actinobacillus actinomycetemcomitans was found in 44% (group A), 40% (group B) and 17% (group C). 72% of the group A and 100% of the group B and C samples contained spirochetes. In all of those positive samples, small spirochetes were present, but only 78% contained medium and only 48% large spirochetes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Changes in subgingival microbiota during puberty. A 4-year longitudinal study.

It was the purpose of the present investigation to monitor the composition of the subgingival microbiota at selected sites in individuals passing through puberty and to correlate observed changes with the development of pubertal maturation. Between the ages of 11 and 14 years, pubertal and skeletal maturation was monitored annually in 22 boys and 20 girls. During this time, subgingival microbial samples were taken every 4th to 5th month (10 times in 4 years) mesially of the upper first molars. High values in total bacterial counts were reached after the onset of puberty, followed by a decrease towards the end of the observation period. The frequency of detection of Actinomyces odontolyticus and of Capnocytophaga sp. increased with time. The frequencies of other selected species, specifically of black pigmenting Bacteriodes sp. were not found to increase when tested by linear and quadratic models of time trend. However, a statistically significant rise in the frequency of detecting B. intermedius and B. melaninogenicus was noted in the initial pubertal phase identified by the onset of testicular growth in boys (p = 0.05). A significant relationship also existed between testes growth and increase of A. odontolyticus (p less than 0.01). In girls, a similar increase was obtained for A. odontolyticus when studied in relation to the Tanner scores for breast development (p less than 0.01). The changes observed in the subgingival microbiota during puberty may be related to the development of gingivitis, which was demonstrated by a higher tendency for gingival bleeding during the course of the pubertal maturation process.

Actinomyces↗
PubMed1990

Microbial changes associated with the development of puberty gingivitis.

In this study, longitudinal changes in the composition of the subgingival microbiota of children between the ages of 11 and 14 and their association with changes of clinical parameters describing gingival health were investigated. During 4 years, subgingival microbial samples were taken in 22 boys and 20 girls 10 times. At the same time the gingival bleeding tendency was recorded by the Papillary Bleeding Index (PBI). A total of 840 samples was evaluated using darkfield microscopy and anaerobic culturing on non-selective and selective media. Children, who developed a marked and sustained increase in mean PBI scores (n = 21), had higher frequencies and mean proportions of spirochetes and Eikenella corrodens than children without pronounced puberty gingivitis (p less than = 0.05). The mean proportion of Actinomyces viscosus was also higher in these children (p less than = 0.05). Among the species discriminated, only Capnocytophaga sp. were found at a higher rate in samples taken immediately before a rise of PBI (p less than = 0.05). The detection frequencies of black-pigmented Bacteroides (particularly B. intermedius) increased later, and were significantly elevated after the establishment of a high bleeding tendency (p less than = 0.05). These findings implicate Capnocytophaga sp. in the initiation of puberty gingivitis, whereas the increased presence of Bacteroides may reflect a change in the subgingival environment secondary to increased bleeding.

Adolescent↗
PubMed1990

Local differences in the newly formed crevicular microbiota.

Subgingival plaque samples were taken from upper and lower right canines, premolars, and first molars (distal, mid-buccal and lingual) in 10 periodontally healthy individuals after four days without oral hygiene. The samples were examined in the darkfield microscope. Counts and proportions of morphotypes were related to the location of the sampled sites. The influence of site location on the distribution of morphotypes was studied by multiple regression analysis. Inter-individual differences were significant for the proportions of cocci, nonmotile rods and fusiform organisms (p less than 0.001), the influence of site location was not. Significant differences (p less than 0.05) were found between total bacterial counts of samples taken from different sites: Distal-buccal samples contained more bacteria than did mid-buccal samples, mid-buccal ones contained more than lingual samples; samples from more posterior teeth contained more bacteria. The experiment was repeated after 5 weeks. The intertest agreement (kappa) for the presence of the different morphotypes ranged between 0.13 and 0.30. Coefficients of variation of the proportions of morphotypes determined in repeated samples were between 1.35 and 3.13.

Adolescent↗
PubMed1989

Treatment of recurrent periodontal disease by root planing and Ornidazole (Tiberal). Clinical and microbiological findings.

The purpose of this study was to evaluate the use of Ornidazole as an adjunct to root planing in the therapy of patients suffering from recurrent periodontal disease. In 10 individuals who had previously been treated with scaling, root planing and periodontal surgery and who had followed a regular maintenance program including recall visits every 3-5 months for 1-7 years, 2 sites with recurrent periodontitis and 1 shallow site were selected. Reinfected sites had a record of losing clinical attachment of more than 3 mm since the completion of initial therapy, were bleeding upon probing and had a mean pocket probing depth of 7.85 +/- 1.31 mm. They had been reinstrumented several times by a registered dental hygienist, when clinical signs of recurrence of disease had appeared and the root surfaces were judged to be smooth and free of deposits. Clinical parameters were recorded and microbial samples were collected twice prior to retreatment. Then, 500 mg Ornidazole, to be taken twice a day for 10 days, was administered, and the whole dentition was thoroughly scaled and root planed. At day 10 as well as 2, 5, 8 and 11 months thereafter, samples were again obtained. At baseline, reinfected sites showed over 20% spirochetes, over 20% motile rods and over 9% fusiform organisms in darkfield preparations of subgingival plaque samples. Culturally, over 1/10 of organisms were identified as black pigmenting Bacteroides and in 18% of all baseline samples collected, B. gingivalis was found.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Reproducibility of microscopic and cultural data in repeated subgingival plaque samples.

In association studies, micro-organisms can only be recognized as suspects for playing a major rôle in the development of a pathological environment, if their destructive action goes along with a marked proportional increase of their numbers or if their first detection can be related to the clinical onset of the disease. Limitations in the reproducibility of repeated samples have to be taken into account, when changes of the microbial composition of subgingival environments are to be studied, and when local clinical changes are to be related to shifts in the composition of the pertaining microbiological compartment. To study reproducibility, a total of 109 sites was sampled repeatedly with sterile paperpoints at an interval of 7 to 10 days in 24 patients suffering from periodontal disease and 12 edentulous patients wearing successful and failing osseointegrated titanium implants. Using continuous anaerobic techniques, the samples were cultured on nonselective and selective media and were studied by darkfield microscopy. Both the intertest-agreements of frequencies of detection (kappa-statistics) as well as the discrepancies of proportions of bacterial groups and selected bacterial species were determined. The standard deviation of proportional differences between first and second samples ranged between 6.4% (fusiform organisms) and 17.2% (coccoid cells) for darkfield parameters, between 4.3% (B. melaninogenicus on ETSA/Kana.) and 14.0% (B. gingivalis on ETSA/Kana.) for selected bacterial species and between 6.9% (gram-negative anaerobic cocci) and 24.0% (gram-positive facultative cocci) for bacterial groups classified according to gram stain characteristics and atmospheric growth conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteria↗
PubMed1989

Gingival health and gingivitis development during puberty. A 4-year longitudinal study.

The purpose of this investigation was to follow the development of the gingival conditions during puberty and to correlate oral clinical parameters with chronological age as well as with parameters used for the determination of the pubertal development. In 22 boys and 20 girls pubertal and skeletal development, as well as plaque index (PlI) and gingival index (GI) were monitored at 1-year intervals between the ages of 11 and 15 years. During this time, the papillary bleeding index (PBI) was assessed 10 times in all interdental spaces of the dentition. The bleeding tendency, represented by whole mouth mean PBI values, as well as the % of bleeding interdental sites, was found to increase significantly with the start of the pubertal phase. It reached a peak value after 1-5 years in 35% of the children. A significant trend of decrease was noted after the age of 14 years in boys and girls. In boys, mean PBI and the % of interdental sites with bleeding were correlated with testes growth, in girls with the Tanner index for secondary sex characteristics (breast development). PlI and GI, which were only recorded annually, did not show a significant trend of increase or decrease.

Adolescent↗