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Biomedical subjects

R Mengel

Publications and source records attributed to R Mengel.

At least 19 recordsLinked to original sources
PubMed2001

Osseointegrated implants in patients treated for generalized chronic periodontitis and generalized aggressive periodontitis: 3- and 5-year results of a prospective long-term study.

BACKGROUND: The successful use of osseointegrated implants in periodontally healthy patients has been documented in numerous longitudinal studies in recent years. However, the extent to which these positive results apply to periodontally diseased patients remains unclear. The aim of the present prospective longitudinal study of partially edentulous patients treated for generalized chronic periodontitis and generalized aggressive periodontitis was a clinical, microbiological, and radiographic comparison of teeth and implants and assessment of the implant success rate. METHODS: Five partially edentulous patients treated for generalized aggressive periodontitis (GAgP) and 5 treated for generalized chronic periodontitis (GCP) were enrolled in this study. The GAgP patients received 36 implants, and the GCP patients 12 implants. The teeth were examined 2 to 4 weeks before extraction of the non-retainable teeth (baseline), and 3 weeks after insertion of the final abutments (second examination). All further examinations were performed during a 3-month recall schedule over a 5-year period for the GAgP patients and over a 3-year period for the GCP patients. At each session clinical parameters were recorded at teeth and implants and the composition of the subgingival microflora was determined by dark-field microscopy and DNA analysis. Intraoral radiographs of the teeth and implants were taken for control purposes at baseline; after insertion of the superstructure; and 1, 3, and 5 years later. RESULTS: The clinical findings indicated healthy periodontal and peri-implant conditions in both patient groups throughout the study. However, an increased probing depth and an attachment loss were recorded in the GAgP patients after the third year (P<0.001). The distribution of the microorganisms revealed no significant differences between the patient groups or between implants and teeth. Moderate bone loss at teeth and implants was registered in both groups. The success rates recorded were 100% in the GCP patients and 88.8% (maxilla: 85.7%; mandible: 93.3%) in the GAgP patients. CONCLUSIONS: The 3-year and 5-year follow-ups show that osseointegrated implants may be successful in oral rehabilitation of partially edentulous patients treated for generalized aggressive periodontitis and generalized chronic periodontitis. However, as no significant differences were recorded between conditions at teeth and at implants, progression of the disease cannot be ruled out.

Adult↗
PubMed1998

Desquamative gingivitis and balanitis--linear IgA disease or cicatricial pemphigoid?

A 38-year-old man presented with gingival inflammation together with erosions of the penis. Direct immunofluorescence demonstrated linear deposits of IgA at the basement membrane zone; indirect immunofluorescence and immunoblotting were negative. Linear IgA disease (LAD) was therefore suspected and treatment with dapsone initiated but this was changed to sulfamethoxy-pyridazine and systemic corticosteroids because of methaemoglobinaemia. During 1-year follow-up the lesions continued to wax and wane although they were never as extensive as before. Eighteen months after disease onset there was scarring of the penis together with suspected fibrosis of the inflamed gingival region. In addition the patient was HLA DQ7(3) positive, a haplotype thought to be increased in patients with cicatricial pemphigoid (CP); LAD with scarring or CP with solely linear IgA deposits are possible diagnoses of his condition.

Adult↗
PubMed1997

An in vitro study of various instruments for root planing.

Rotating instruments are becoming increasingly significant in the scaling and planing of the root surface. The objective of this in vitro study was to test various root-planing instruments on extracted teeth and then to compare the treated surfaces using scanning electron microscopy. Two manual instruments (scaler and curette) and five mechanically rotating instruments (Desmo-Clean; Perio-Set; Viking-Set; and 40-microns and 15-microns diamond finishers) were investigated. From a total of 42 teeth, six root surfaces were treated with each instrument. The results confirm the clear superiority of the manual instruments (especially the curette). The manual instruments permit good root planing with minimum ablation from the root surface and only a thin smear layer (a compound of grinding dust, dentinal fluid, and water). The best planing results by rotating instruments were achieved with the Desmo-Clean and the 15-microns diamond finisher, whose performance was almost equal to that of the manual instruments. The rotating instruments, however, were associated with higher ablation and a marked smear layer. Manual instruments remain the media of choice on easily accessible root surfaces; however, rotating instruments are of advantage in inaccessible areas (eg, furcations) because of their handling properties.

Bicuspid↗
PubMed1996

Comparative study of plaque and gingivitis prevention by AmF/SnF2 and NaF. A clinical and microbiological 9-month study.

This comparative clinical 9-month study was designed to examine the efficacy of amine/stannous fluoride (AmF/SnF2) (Meridol) and sodium fluoride (NaF). 150 probands with chronic gingivitis or early signs of periodontitis were divided into 3 randomised groups. Group 1 was given a NaF toothpaste and an NaF mouthrinse, group 2 AmF/SnF2 toothpaste and mouthrinse, and group 3 AmF/SnF2 toothpaste and NaF mouthrinse. The probands were examined at intervals (0, 1, 3 and 9 months) under conditions of a clinical double-blind study. The parameters recorded were the plaque index (PlI), the approximal plaque index (API), the gingival index (GI) and the mod. sulcus bleeding index (SBI). The probing depths (PD) were also measured. The composition of the supragingival plaque was evaluated by dark-field microscopy. A highly significant reduction in all clinical parameters was recorded in all 3 groups in the course of the study. The most pronounced reduction in PlI, API, SBI and PD was recorded in group 2. In the group comparison, however, no significant differences were recorded. Microbiological examination revealed a highly significant increase in cocci and a decrease in rods in all 3 groups. There was also a significant reduction in spirochetes, filaments and fusiforms in groups 2 and 3. In group 1, there was a significant fall only in fusiforms and small spirochetes. Overall, no significant difference in clinical parameters was recorded in the group comparison. However, the use of AmF/SnF2 toothpaste and mouthrinse (group 2) and, to a lesser degree, the combined use of AmF/SnF2 toothpaste and NaF mouthrinse display a favorable microbiological effect. The results from the present double-blind study reveal a reduction in gingival inflammation and supragingival plaque accumulation with a positive change in plaque flora in all groups. The reduction in potentially gingivopathogenic bacteria was slightly higher in the amine/stannous fluoride group.

Adolescent↗
PubMed1996

Periodontal status of a subject sample of Yemen.

From August to October 1991, the periodontal status of 1001 Yemenis representing the age groups 12-14, 15-19, 20-24 and 35-44 years was recorded and evaluated with reference to the CPITN, the calculus index and clinical attachment levels. The impact of chewing khat, the leaves of a cultivated, alkaloid shrub, and of using the traditional miswak chewing stick for oral hygiene purposes were investigated. The results show that 6.9% of the juvenile probands (15-19 years) had healthy periodontal tissue (CPITN 0), whereas bleeding on probing and calculus (CPITN 1 + 2) were registered in 86.2%. In the 35-44 year age group, 1.7% were periodontally healthy, whereas 84.5% displayed plaque retention or shallow pocketing (CPITN 2 + 3) and 12.5% deep pocketing (CPITN 4). The treatment needs in all age groups are confined primarily to calculus removal and instruction in oral hygiene. The clinical attachment level and the calculus index revealed age-related attachment loss and calculus formation, primarily among male probands. The higher khat consumption among the male population is reflected in its detrimental effect on the periodontal tissue, especially among younger probands. Oral hygiene aids have also an influence on periodontal status, with a toothbrush proving more efficient than the miswak. WHO efforts directed towards prophylactic programs need to be intensified but can be staffed by dental hygienists.

Adolescent↗
PubMed1996

Osseointegrated implants in patients treated for generalized severe adult periodontitis. An interim report.

This study presents oral rehabilitation with osseointegrated implants in partially edentulous patients treated for generalized severe adult periodontitis. Five female patients aged between 31 and 44 received a total of 36 implants and were observed for 1 year after insertion of the superstructure. Three months before implantation, venous blood samples were taken from the patients and five periodontally healthy controls, and the serum examined with highly sensitive ELISA test kits for interleukin 1 beta (IL-1 beta) and interleukin 6 (IL-6). Clinical examination covered the plaque index (PI) and gingival index (GI) at teeth and implants plus probing depth (PD) and clinical attachment level (CAL) at the teeth. Microbiological evaluation of teeth and implants was performed by dark-field analysis, and DNA analysis was performed in addition 1 year after insertion of the superstructure. Radiological controls of the teeth were carried out with standard single-tooth films in the 2 years preceding implantation and at baseline. Following implantation, further controls of the teeth and implants were undertaken immediately after insertion of the superstructure and 1 year thereafter. The immunological examination revealed that the IL-1 beta (0.22 +/- 0.2 pg/ml) (means +/- SD) and IL-6 (2.27 +/- 2.8 pg/ml) level was slightly, but not significantly, higher in the patients than in the control group (IL-1 beta: 0.06 +/- 0.06 pg/ml and IL-6: 0.64 +/- 0.2 pg/ml) (P > 0.05). The clinical results show that the GI at the teeth rose slightly from 0.0 to 0.2, and at the implants from 0.3 to 0.4. The PI rose slightly from 0.3 to 0.7 at the teeth and from 0.2 to 0.9 at the implants. Neither the GI nor the PI revealed any significant difference between teeth and implants. Clinical attachment loss at the teeth was minimal at 4.7 to 4.8 mm. Comparison between the teeth and the implants revealed no essential difference in bacterial flora; neither Actinobacillus actinomycetemcomitans nor Porphyromonas gingivalis was recorded at any location. Small quantities of Prevotella intermedia were detected at the teeth and implants of one patient. Radiological evaluation 1 year after insertion of the superstructure revealed a mean bone loss of 0.62 mm at the implants. The bone loss at the teeth during the same period was 0.3%, whereas it had been 1.5% in each of the 2 previous years. These results suggest that there is only a slight difference between the periodontal and peri-implant areas in patients with generalized severe adult periodontitis. The full potential for implants in these patients, however, needs to be shown in controlled longitudinal studies.

Adult↗
PubMed1994

An in vitro study of oscillating instruments for root planing.

The objective of this in vitro study was to test PER-IO-TOR instruments on the Profin Directional System angle piece (Dentatus-Sweden), using extracted human teeth. In the 1st part of the study, 6 root surfaces were treated with the instruments TOR 1, TOR 2, TOR 3 and TOR 4. For comparison purposes, half the samples treated with each instrument were then subjected to further treatment with a Gracey curette. All samples were then examined by SEM. In the 2nd part of the study, 4 root surfaces were given standardized treatment with each PER-IO-TOR instrument and the amount of substance removed was determined with a mechanical profilometer. For this purpose, the treated root surface was scanned with a microneedle and the profile depth recorded. The study showed that the PER-IO-TOR instruments were efficient with respect to surface planning and protective abrasion. Instrument TOR 3 (spatula with eyelet) in particular yielded similar results to those obtained with a curette. The overall results confirm that the PER-IO-TOR instruments have similar planing properties to manual instruments, causing minimum abrasion from the root surface. They thus represent an alternative to manual instruments, not only in inaccessible areas but also on smooth tooth surfaces.

Dental Calculus↗
PubMed1993

Periodontal health of the population in eastern Germany (former GDR).

The periodontal status of 1688 inhabitants of eastern Germany (former GDR) was investigated between July 1991 and March 1992, using the CPITN. The results show that only 1.4% of those examined have a healthy periodontal apparatus, whereas 40.1% had some signs of severe periodontitis (CPITN 4). This implies a very high therapy requirement in all age-groups, with 93.1% of 15- to 19-year-olds in need of peridontal treatment (CPITN 1 + 2 + 3 + 4). A comparison between educational qualifications and frequency of brushing or routine dental checks reveals a better level of prophylaxis in the more educated classes. As expected, the CPITN code with good oral hygiene and regular dental checks was significantly lower than with poor oral hygiene and infrequent dental checks. The high prevalence of periodontal disease lends urgency to the development of an extensive prevention concept introduced in childhood.

Adolescent↗
PubMed1992

CPITN application in regular dental practice.

The periodontal status of 8862 dentulous and partially dentulous inhabitants of the Federal Republic of Germany was investigated in various dental practices, using the CPITN, developed by the World Health Organization. The results show that a total of only 4.3% of those examined have a healthy periodontal apparatus and thus require no periodontal treatment. At least detailed oral hygiene instruction needs to be given to 95.7% of all subjects. Furthermore, 80% patients with periodontal disease require scaling or root planing, and 10% of them require periodontal surgery. The treatment of shallow gingival pocketing (CPITN 3) is predominant in every age group, and every fifth patient aged 35 years or more is need of periodontal surgery. This high frequency rate of periodontal disease illustrates the urgent necessity in regular dental practice for each and every patient to undergo periodontal screening. Such screening, based on the time saving CPITN, is to be recommended as it ensures fast, reliable determination of the periodontal status of each individual patient and the treatment needs involved.

Age Factors↗
PubMed1991

[Clinical indices in periodontal diagnosis. A review].

In this review, are described the most common clinical indices. Further, is discussed and criticized their application as well as usefulness in the clinical diagnosis and patient management. Although, there exists a variety of clinical indices, only a few of them could be sufficient for monitoring diagnosis and treatment in the general practice.

Dental Health Surveys↗
PubMed1991

[Sulcus fluid in periodontal diagnosis. A review].

In the present review, the composition of the gingival crevicular fluid (GCF) as well as its important role in the diagnosis of periodontal disease have been discussed. Furthermore, the different sampling methods and the subsequent analytical procedures have been described. Some of the GCF-components, such as elastase, prostaglandin, arylsulphatase and beta-glucuronidase, are examined for their use as suitable markers of future disease activity. At the present time, the interest of research is focussing on the host-parasite interaction, the prediction of disease activity, and the identification of risk groups of patients. Therefore, GCF is considered a valuable research subject and a possible diagnostic marker.

Gingival Crevicular Fluid↗
PubMed1991

[Periodontal status in Rio de Janeiro city (Brazil)].

The periodontal status and the treatment needs were investigated in 1854 residents of Rio de Janeiro City (Brazil) by means of the CPITN. The results of the study showed that 2.5% of the examined individuals were healthy (CPITN 0), 8.1% displayed an increased tendency towards bleeding on probing (CPITN 1) and 23.2% presented with calculus and bleeding on probing (CPITN 2). Shallow pocketing (CPITN 3) was observed in 51.4% and deep pocketing (CPITN 4) in 14.7% of the examined subjects. Since 97.5% of the examined population were in need of periodontal therapy, the necessity for organizing an oral health program with emphasis on prevention and treatment of periodontal disease is strongly indicated.

Age Factors↗
PubMed1985

The effect of 2'-fluoro-2'-deoxycytidine on herpes virus growth.

The effect of 2'-fluoro-2'-deoxycytidine (dCfl) on the growth of certain viruses of the herpes type was investigated. It is shown that the compound has considerable anti-viral activity against HSV-I, HSV-II, pseudorabies virus and equine abortion virus. It has an effect comparable to that of araC and is more efficient than br5dC, but less so than acyclovir. Experiments with thymidine kinase-negative strains of HSV-I indicated that dCfl was phosphorylated by the viral kinase, and its Km appears to be low and close to that of thymidine. Density gradient centrifugation enabled us to show that dCfl was incorporated into cellular and viral DNA and RNA. The cytotoxic activity of dCfl appears to be about 10-times smaller than that of araC. Removal of the nucleoside analog, washing and replacement with deoxycytidine reversed this effect, indicating rather a cytostatic than cytotoxic effect.

Animals↗
PubMed1977

Solution conformational analysis of 2'-amino-2''deoxyadenosine, 3'-amino-3'-deoxyadenosine and puromycin by pulsed nuclear-magnetic-resonance methods.

The solution conformation of 2'-amino-2'-deoxyadenosine, 3'-amino-3'-deoxyadenosine, and 3'-amino-3'-deoxy-6-N,N-dimethyladenosine have been determined by nuclear magnetic resonance in aqueous and ammonia solutions. The analysis of the ribose moiety is based on the two-state S in equilibrium N model of Altona and Sundaralingam. Longitudinal proton relaxation time and nuclear Overhauser enchancement measurements have been carried out in order to characterize the orientation of the base relative to the ribose. Those studies indicate that 3'-amino-3'-deoxyadenosine and 3'-amino-3'-deoxy-6-N,N-dimethyladenosine exist in solution preferentially in the N-anti-g + conformations. On the other hand, 2'-amino-2'-deoxyadenosine adopts the S-syn-g +/t conformation families. It appears that the base is restricted to the anti conformation in the first two compounds, while in 2'-amino-2'-deoxyadenosine, one third of the molecules in the S state are in the anti range. These studies corroborate the previously proposed correlations between the N state of the ribose and the anti orientation of the base and between the S state of the ribose and the syn orientation of the base.

Deoxyadenosines↗