Dark-field microscopic monitoring of subgingival bacteria during periodontal therapy

Understanding the microbial components of periodontal diseases and periodontal treatment-induced microbiological shifts

In the mid-1960s the microbial aetiology of periodontal diseases was introduced based on classical experimental gingivitis studies . Since then, numerous studies have addressed the fundamental role that oral microbiota plays in the initiation and progression of periodontal diseases. Recent advances in laboratory identification techniques have contributed to a better understanding of the complexity of the oral microbiome in both health and disease. Modern culture-independent methods such as human oral microbial identification microarray and next-generation sequencing have been used to identify a wide variety of microbial taxa residing in the gingival sulcus and the periodontal pocket. The first theory of the 'non-specific plaque' hypothesis gave rise to the 'ecological plaque' hypothesis and more recently to the 'polymicrobial synergy and dysbiosis hypothesis'. Periodontitis is now considered to be a multimicrobial inflammatory disease in which the various bacterial species within the dental biofilm are in a dysbiotic state and this imbalance favours the establishment of chronic inflammatory conditions and ultimately the destruction of tooth-supporting tissues. Apart from the known putative periodontal pathogens, the whole biofilm community is now considered to play a role in the establishment of inflammation and the initiation and progression of periodontitis in a susceptible host. Treatment is unlikely to eliminate putative pathogens but, when it is thoroughly performed it has the potential to establish a healthy ecosystem by altering the microbial community in numbers and composition and also contribute to the maturation of the host immune response.

The effects of intensive oral care before surgery for gastric cancer patients

OBJECTIVES

Oral function management has been recognized as important strategy for preventing postoperative complications. In this historical cohort study, we focused on the patients who planed gastrectomy, and investigated the appropriate duration and frequency of preoperative oral care to prevent complications after surgery.

METHODS

Patients who planed surgery for gastric cancer between 2012 and 2018 were enrolled. We defined intensive oral care (IOC) as initial intervention at least three weeks before surgery and follow-up intervention within a week before surgery. As the primary outcome, the incidence of postoperative infectious complications was compared between the IOC and non-intensive oral care groups.

RESULTS

A total of 576 patients were enrolled, including 66 with IOC. The incidence of infectious complications was 2/66 (3.0%) in the IOC group and 64/510 (12.5%) in the non-intensive oral care group. After adjusting for confounding factors, patients with IOC exposure had a lower chance of developing postoperative infectious complications (odds ratio; 0.217, 0.051-0.927).

CONCLUSIONS

Intensive oral care can help prevent postoperative infectious complications after gastrectomy. These findings suggest that appropriate preoperative oral care includes at least two interventions: three weeks or more before and within one week before surgery.

Three-dimensional real-time darkfield imaging through Fourier lightfield microscopy

We report a protocol that takes advantage of the Fourier lightfield microscopy concept for providing 3D darkfield images of volumetric samples in a single-shot. This microscope takes advantage of the Fourier lightfield configuration, in which a lens array is placed at the Fourier plane of the microscope objective, providing a direct multiplexing of the spatio-angular information of the sample. Using the proper illumination beam, the system collects the light scattered by the sample while the background light is blocked out. This produces a set of orthographic perspective images with shifted spatial-frequency components that can be recombined to produce a 3D darkfield image. Applying the adequate reconstruction algorithm high-contrast darkfield optical sections are calculated in real time. The presented method is applied for fast volumetric reconstructions of unstained 3D samples.

Assessing Bone Type of Implant Recipient Sites by Stereomicroscopic Observation of Bone Core Specimens: A Comparison With the Assessment Using Dental Radiography

BACKGROUND

The aim of the study is to determine if bone quality evaluation of surgically obtained bone core specimens using a stereomicroscope is reliable for determining bone quality at implant recipient sites.

METHODS

Bone quality was presurgically assessed in 122 edentulous ridges obtained from 62 patients using periapical radiographs and categorized according to the Lekholm and Zarb classification. During surgery, bone specimens were trephined, and bone types were immediately classified using a stereomicroscope. Microarchitectural characteristics of bone cores were evaluated after being scanned using microcomputed tomography (micro-CT).

RESULTS

Bone types of implant sites categorized from radiography and stereomicroscope had statistically similar distribution but poor interrater agreement. Using micro-CT, maxillae and mandibles showed significant differences in microarchitectural characteristics of bone cores. Bone volume (BV), total volume (TV), and trabecular thickness (Tb.Th) increased, whereas bone surface density (BS/BV) and open porosity (Po.[Op]) decreased in mandibular bone cores compared with those in maxillary bone cores. Moreover, micro-CT values of BV/TV and Po.(Op) statistically correlated with bone types assessed by stereomicroscopy, particularly in mandibles (adjusted means of BV/TV of Type 2 to 4 versus Type 1 decreasing from -9.88%, -15.09%, -29.31%; those of Po.(Op) ranged from 9.77%, 15.06%, 29.52% in an upward trend). However, such correlations were not found in maxillae or when bone types were classified using periapical radiographs.

CONCLUSIONS

Caution is needed when using presurgical periapical radiographs to predict bone quality at implant recipient sites. Surgically preserved bone core specimens, whenever obtainable, might offer additional information to accurately assess bone quality, particularly at mandibular implant sites.

Evaluation of two local drug delivery systems as adjuncts to mechanotherapy as compared to mechanotherapy alone in management of chronic periodontitis: A clinical, microbiological, and molecular study

BACKGROUND

Modern concepts of treating inflammatory periodontal disease aim at changes in the subgingival ecosystems within the periodontal pockets to alter the complex microbial community into a microbiota compatible with good periodontal health. Systemic antimicrobial therapy, although effective, involves a relatively high dose with repeated intakes over a prolonged period of time to achieve the required inhibitory concentrations in the sulcular fluid. The adjunctive use of local drug delivery may provide a beneficial response, especially in specific areas where conventional forms of therapy might fail. The aim of this study was to compare the efficacy of two local drug delivery systems, one containing metronidazole and the other containing tetracycline hydrochloride as adjuncts to mechanotherapy in the treatment of chronic periodontitis.

MATERIALS AND METHODS

There were three groups that were labeled as group A (Scaling + Tetracycline), group B (Scaling + Metronidazole), and group C (Scaling alone). A microbiological analysis was carried out to determine the efficacy of these systems in changing the pathogenic flora in deep pockets. In addition, a multiplex polymerase chain reaction was carried out to confirm the presence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis (Pg), and Tannerella forsythensis in the flora associated with chronic periodontitis.

RESULTS

There was clinical improvement in groups A and B, which correlated with an improvement in the microbiological parameters; these results were sustained for 90 days following therapy. In Group C, the flora showed a shift towards baseline at the end of 90 days.

CONCLUSIONS

According to this study, both the local antibiotic therapies resulted in greater improvement in microbiological parameters when used as an adjunct to mechanotherapy as compared to mechanotherapy alone.

Decreased interleukin-2 responses to Fusobacterium nucleatum and Porphyromonas gingivalis in generalized aggressive periodontitis

BACKGROUND

Compromised T-cell responses to periodontal pathogens may contribute to the pathogenesis of generalized aggressive periodontitis (GAgP). In this study, we attempted to characterize T-helper cell (Th1, Th2, and Th17) responses in patients with GAgP and healthy controls upon stimulation with disease-relevant pathogens.

METHODS

Mononuclear cells (MNCs) from 10 white patients with GAgP and 10 white controls were stimulated with Porphyromonas gingivalis American Type Culture Collection (ATCC) 33277 (Pg), Prevotella intermedia ATCC 25611, Fusobacterium nucleatum ATCC 49256 (Fn), and similar bacteria isolated from the participants' inherent oral flora. Tetanus toxoid (TT) was used as control antigen. The resulting production of interferon-gamma (IFN-gamma) and interleukin (IL)-2, -4, -5 and -17 and the induced proliferation of CD4+ T cells were measured.

RESULTS

MNCs from patients with GAgP exhibited decreased IL-2 responses to Pg and Fn. No difference was observed between patients with GAgP and controls with regard to CD4+ T-cell proliferation or the production of IFN-gamma and IL-4, -5, and -17, irrespective of whether type strains or bacteria isolated from the participants' oral cavity were used for stimulation. Moreover, similar proliferative and cytokine responses to TT were observed. Notably, smoking patients with GAgP exhibited significantly lower IFN-gamma responses to the bacteria and to TT than non-smoking patients or controls.

CONCLUSIONS

The decreased IL-2 responses of patients with GAgP to Pg and Fn combined with adequate IL-2 responses to TT suggest an impaired antigen-specific T-cell reactivity with periodontal pathogens in GAgP. The decreased IFN-gamma responses of smokers within the patient group suggest that smoking may aggravate this impairment.

Microbiological diagnostic testing in the treatment of periodontal diseases

A variety of microbiological diagnostic tests are available for clinicians to use for evaluation of patients with periodontal disease. Each one has its own unique set of advantages and disadvantages, and probably the most useful information for the clinician can be obtained using a combination of the various analytic methods. The tests appear to have their greatest utility when used on patients with chronic or aggressive periodontitis who do not respond favorable to conventional mechanical therapy. The major limitation of all microbiological tests is that the information obtained is relevant to the site sampled, and may not be representative of the microflora of the entire dentition. However, since it is often only specific sites that do not respond to initial therapy, knowing the constituents of the microflora that populate these sites is clinically relevant.

Clinical significance of non-surgical periodontal therapy: an evidence-based perspective of scaling and root planing

Analysis of Egyptian hieroglyphics and medical papyri indicate that non-surgical periodontal treatment was common 3000-4000 years ago. Even today, scaling and root planing (SRP) remains an essential part of successful periodontal therapy. The collective evidence from numerous clinical trials reveals a consistency of clinical response in the treatment of chronic periodontitis by SRP using manual, sonic, or ultrasonic instrumentation. Thus, SRP remains the 'gold standard' to which more recently developed therapeutic modalities must be compared. Inherent to the clinical evaluation of SRP are such concerns as manual versus sonic and ultrasonic instrumentation, control of sub-gingival bacterial populations, removal of calculus, root smoothness and changes in various clinical parameters, e.g. probing depth, attachment levels, bleeding on probing and gingival inflammation. Lastly, an abbreviated discussion is presented on a relatively new paradigm of complete mouth 'disinfection' in a compressed time-frame that includes SRP as a significant component of the treatment regimen.

The significance of prior mechanical therapy for changes of periodontal status achieved by local delivery of a doxycyclinehyclate containing gel

AIM

The purpose of this retrospective analysis was to examine what effect, if any, the time elapsed between an individual's last episode of scaling and root planing and subsequent treatment with a sustained-release doxycycline hyclate gel (DH) alone or scaling and root planing alone (SRP) would have upon adult periodontitis.

METHODS

A total of 207 subjects were included in the DH group and 210 patients in the SRP group. Periodontitis was defined as those sites which presented with pocket depths > or =5 mm and exhibited bleeding upon probing. In both DH and SRP groups, 3 sub-groups of subjects were identified according to their last episode of scaling and root planing prior to the study baseline: within 2 to 6 months, >6 but < or =12 months, and one or more times in their life but not within the last 12 months. Each study site was treated twice over a 9-month study period, once at baseline and again at 4 months. Data from the study sites at 4, 6, and 9 months were then evaluated for changes in probing depth, clinical attachment level, and bleeding upon probing.

RESULTS

At the 9-month evaluation, all sub-groups in the DH and SRP treatment arms presented with improvement in the measured clinical parameters, as compared to baseline. No significant differences were observed in the measured periodontal indices among the study sites between the three sub-groups for either treatment.

CONCLUSIONS

It is concluded that the time interval since the last episode of scaling and root planing had no observable effect on the results achieved when treating periodontitis sites with locally delivered doxycycline hyclate alone or scaling and root planing alone. The treatment of periodontitis sites with locally delivered doxycycline hyclate resulted in clinical improvement comparable to scaling and root planing irrespective of the patient's prophylaxis frequency.

Microbiological response to mechanical treatment in combination with adjunctive therapy. A review of the literature

The recognition of the microbial origin and the specificity of periodontal infections has resulted in the development of several adjunctive therapies (antibiotics and/or antiseptics) to scaling and root planing in the treatment of chronic adult periodontitis. This article aims to review the "additional" effect of a subgingival irrigation with chlorhexidine, or a local or systemic application of tetracycline or metronidazole, performed in combination with a single course of scaling and root planing in patients with chronic adult periodontitis. All treatment modalities are compared with scaling and root planing, based on their impact on: the probing depth (PD); total number of colony forming units per ml (CFU/ml); the proportions and/or the detection-frequency of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia; and/or on the percentages of cocci, spirochetes, motile, and other micro-organisms on dark field microscopy examination. All treatment modalities, including scaling and root planing without additional chemical therapy, resulted in significant reductions in the probing depth and the proportions of periodontopathogens, at least during the first 8 weeks post-therapy. However in comparison to a single course of scaling and root planing, the supplementary effect of adjunctive therapies seems to be limited. In general, only the irrigation with chlorhexidine 2%, the local application of minocycline, and the systemic use of metronidazole (in case of large proportions of spirochetes) or doxycycline (in case of large proportions of A. actinomycetemcomitans) seem to result in a prolonged supplementary effect when compared to scaling and root planing. Therefore, the use of antibiotics on a routine basis, especially in a systemic way, in the treatment of chronic adult periodontitis, can no longer be advocated, considering the increasing danger for the development of microbial resistance.

Iron acquisition by oral hemolytic spirochetes: isolation of a hemin-binding protein and identification of iron reductase activity

Oral anaerobic spirochetes (OAS) have been implicated in the etiology of periodontal disease. To adapt to the environment of the subgingiva, OAS must be able to acquire iron from limited sources. OAS have previously been shown not to produce siderophores but are beta-hemolytic and can bind hemin via a proteinaceous 47-kDa outer membrane sheath (OMS) receptor. Present studies show that [3H]hemin is not transported into the cytoplasm, that hemin and ferric ammonium citrate, as the sole iron sources, can support the growth of OAS and that protoporphyrin IX and Congo red are inhibitory, thereby implying an important in vivo role for hemin as an iron source. Treponema denticola ATCC 35405 produces an iron reductase. The iron reductase can reduce the central ferric iron moiety of hemin. The 47-kDa OMS hemin-binding protein has been purified to apparent homogeneity by methanol-chloroform extraction of cellular lipoproteins and the use of a hemin-agarose bead affinity column. A model of iron acquisition by OAS is presented.

A feasibility study on the use of direct light silver stain compared with dark field microscopy for differential counting of subgingival plaque

The purpose of the present study was to compare direct light microscopy using a silver stain, with dark field microscopy for differential counting of subgingival plaque samples from patients with periodontitis. The feasibility of using the staining method was assessed on subgingival plaque samples which were collected at 34 sites from patients with untreated adult periodontitis. Differential counts of plaque morphotypes assessed by both methods showed close agreement. The proportions of spirochaetes assessed by both methods were significantly associated with probing depth. The silver stain proved a simple, rapid and inexpensive method for differential counting of plaque composition. This method is suitable for possible use in general dental practice where smears could be made at the chair-side and allowed to dry ready for staining and counting at the dentist's convenience using a simple light microscope. A permanent record is also produced which could allow for comparison of samples from before and after treatment and could be used as an aid to patient motivation in suitable cases.

Microscopic spirochete counts in untreated subjects with and without periodontal tissue destruction

The purpose of the study was to determine microscopically the %s of spirochetes at sites without periodontal destruction in subjects with destructive periodontal diseases (cases) and in subjects free of it (controls), who had not received professional prophylaxis. From a sample of 164 individuals aged between 30-44 years living in rural and urban areas of Tanzania, cases and controls were selected. Cases (n = 25) were selected who exhibited at least 3 teeth with pocket depth of > 5 mm. The controls (n = 28) had no pockets deeper than 3 mm. From each subject, 1 subgingival plaque sample was taken at the mid point of the lingual surface of 1 of the upper premolars which showed bleeding on probing but no calculus and no pockets. In addition, one subgingival sample was obtained from a pocket. Pockets contained the highest %s of spirochetes, which confirms earlier findings. A significant difference in % of spirochetes between cases and controls was found at non-destructive sites, indicating a host effect on the subgingival microflora. However, the spirochete counts at non-destructive sites did not provide a reliable measure to identify subjects with destructive periodontal disease.

Evaluation of the antimicrobial effects of sodium benzoate and dichlorobenzyl alcohol against dental plaque microorganisms. An in vitro study

Evaluation of antimicrobial agents is based on in vivo and in vitro studies. The minimum inhibitory concentrations (MICs) of sodium benzoate and dichlorobenzyl alcohol to 115 strains of plaque microorganisms were determined by a broth-dilution method. Sodium benzoate did not inhibit growth of any gram-positive cocci (MIC > 106,590 microM). MICs for Porphyromonas gingivalis and two strains of Treponema socranskii were 26,650 microM. The MIC of dichlorobenzyl alcohol to the reference strain of Actinobacillus actinomycetemcomitans was 723 microM and to P. gingivalis, two strains of T. socranskii, and Candida albicans 1,446 microM. MICs for other organisms were 2,892 to 5,784 microM. Saliva samples from 10 volunteers, collected at various times after toothbrushing with a dentifrice containing 10% sodium benzoate and 0.3% dichlorobenzyl alcohol, were analyzed gas-chromatographically. Immediately after toothbrushing mean levels of sodium benzoate and dichlorobenzyl alcohol were 372,626 microM and 7,529 microM, respectively. After 5 min mean levels were 38,700 microM and 734 microM. In conclusion, the concentrations of both antimicrobials dropped rapidly during the first 30 min, but for 5-10 min they were high enough to inhibit growth of potential periodontal pathogens.

Localized prepubertal periodontitis in a 5-year-old child: investigations and clinical observations over a 3-year period

A 5-year-old boy presented with persistent generalized gingival inflammation. Clinical and radiographic examination supplemented by immunological and microbiological investigation led to a diagnosis of localized prepubertal periodontitis. The child was subsequently monitored for 3 years and despite treatment there was continued bone loss related to his primary teeth. This case highlights the need for liaison between specialists in paediatric dentistry, periodontology, immunology and microbiology in order to diagnose prepubertal periodontitis and to establish a rational basis for treatment to prevent progression to juvenile periodontitis.

Changes in amount of gingival crevicular fluid after a single episode of periodontal treatment

A total of 51 periodontal sites from 6 adults with no systemic diseases or medication were selected for the study. All sites showed radiologic bone loss and pockets of 4 mm or more. Crevicular fluid (CF) was collected by inserting filter paper strips into periodontal pockets for 5 s and was measured by Periotron. Samples were collected before and 2, 5, 10, 20, and 40 days after a single episode of periodontal treatment (scaling, root planing and curettage). Plaque Index (P1I), Papilla Bleeding Index (PBI) and pocket depth (PD) were measured before and 40 days after treatment. The amount of bone loss was estimated from orthopantomograms taken immediately before the trial. Two days after treatment an increase in the amount of CF was seen. After this the amount of CF decreased, reaching the pretreatment level on day 5 after treatment and a level clearly below pretreatment level on day 10 after treatment. Forty days after treatment a slight increase in the amount of CF was seen. The difference between pretreatment values and values at days 2, 10, 20, and 40 was highly significant. In pretreatment samples, positive correlations were found between the amount of CF and PD, PBI and bone loss and, in samples collected 40 days after treatment between CF and PD. CF measurements made before treatment were of no value in predicting the changes in clinical parameters after treatment.

Associations between subgingival plaque bacterial morphotypes and clinical indices?

The aim of the present study was to evaluate possible associations between subgingival plaque bacterial morphotypes, as assessed by darkground microscopy, and clinical indices of routine adult chronic periodontitis. Clinical indices were plaque index (PlI), gingival index (GI), sulcus bleeding index (SBI), papilla bleeding index (PBI), attachment loss (AL), pocket depth (PD) and probeable pocket depth (PPD). Apical border plaque was sampled in vivo and after extraction to test whether direct or indirect sampling affected any such associations. Similarly, pocket depth and attachment loss were also assessed directly and indirectly on the same teeth, in vivo or after extraction. The influence of the type of index used to record inflammation (GI, SBI, PBI) was also assessed, as were the effects of the numbers of sampled subjects and the method of analysis, which comprised the use of transformed and untransformed data and of parametric and non-parametric tests. Data were collected in relation to the approximal surfaces of 44 teeth extracted from 22 adults (2 teeth each) and from 1 pair of contralateral upper anterior or premolar teeth in each of 100 adults, all which untreated routine chronic periodontitis. Selected subjects had greater than or equal to 4 mm probeable pocket depth and/or attachment loss, and radiographic evidence of bone loss in relation to 1 approximal surface on each of 1 pair of contralateral anterior or premolar teeth, or to 2 teeth scheduled for extraction. Plaque preparation and darkground microscopy were as described previously. Insignificant associations (p greater than 0.05) were demonstrated between supragingival plaque (PlI) and periodontal inflammation (GI, SBI, PBI) or destruction (PPD and AL), as well as between inflammation and attachment level. In contrast, significant moderate associations (r = 0.5-0.77) were demonstrated between each of the 3 morphotype groups; spirochaetes, other motiles and cocci. Spirochaetes showed a significant moderate (r = 0.5) positive association with pocket depth with a 2.43% mean increase of spirochaetes for each 1 mm increase of PPD. Although highly significant associations (r = 0.9) were demonstrable between the 3 inflammation indices (GI, SBI, PBI) themselves, only PBI showed significant positive associations (r = 0.3) with spirochaetes and other motiles. Also, PlI showed significant associations with each of the 4 morphotypes (r = 0.3-0.5). The heterogeneity of spirochaetes and other motiles as well as the multiplicity of possible aetiological microbial agents in plaque may have resulted in underestimated associations between subjects as well as undetectable association within a given mouth using only 4 morphotype groups.(ABSTRACT TRUNCATED AT 400 WORDS)

Evaluation of stannous fluoride and chlorhexidine sprays on plaque and gingivitis in handicapped children

The objective of this study was to evaluate the effect of twice-daily oral sprays of 2 ml chlorhexidine (0.2%) and 2 ml stannous fluoride (0.2%) as the sole oral hygiene measure on plaque and gingivitis in handicapped children. 52 institutionalized mentally handicapped individuals (aged 10-26 years) were divided into 4 groups to participate in a 9-week, double-blind, randomized clinically controlled trial, which included a cross-over. For the first 3 weeks, groups 3 and 2 had their mouths sprayed with chlorhexidine and stannous fluoride, respectively. Following a 3-week wash-out interval, groups 1 and 4 were sprayed with chlorhexidine and stannous fluoride, respectively. The alternate groups received a placebo, water. Plaque (PI) and gingival indices (GI) were recorded. Subgingival plaque samples were collected and counts of spirochaetes, motile rods and cocci were taken using darkfield microscopy. By the 9th week of trial, the PI and GI were reduced by 48% and 52% for the stannous fluoride group. In the chlorhexidine group, reductions of 75% (PI) and 78% (GI) were achieved. Pair-wise comparisons of placebo, stannous fluoride and chlorhexidine using the U-test of Mann-Whitney revealed significant (p less than 0.05) differences for both PI and GI scores in the placebo/stannous fluoride and placebo/chlorhexidine pair by the 9th week of the trial. In the stannous fluoride/chlorhexidine pair, only the PI was significantly reduced for those on chlorhexidine. Coccoid cells were more dominant at sites with low PI and GI scores (stannous fluoride and chlorhexidine groups), while spirochaetes and motile rods were more frequent at sites with high PI and GI scores (placebo group).

Evaluation of acrylic strips containing amoxycillin with clavulanic acid for local drug delivery

The in vitro release of amoxycillin with clavulanic acid from acrylic strips at initial concentrations of 30, 40 and 50 per cent w/w was monitored using a double-beam ultraviolet spectrophotometer and compared with release of tetracycline hydrochloride. Highest levels of the antibacterial agents were released during the first 24 h period. Therapeutic levels of the drugs continued to be released during the subsequent 9 day period and were shown to be biologically active. Furthermore, for amoxycillin with clavulanic acid, an initial concentration of 40 per cent gave the highest level of release on day 10; while, for tetracycline, 50 per cent provided the highest level of release. Local application of 40 per cent amoxycillin with clavulanic acid incorporated into acrylic strips placed in periodontal pockets in patients with established periodontitis produced a marked change in the subgingival microflora as monitored by dark-field microscopy and cultural techniques. These changes in the subgingival flora were concomitant with elimination of bleeding on probing at the treated sites and were still evident 3 weeks after removal of the acrylic strips. The sensitivity of Bacteroides gingivalis (syn. Porphyromonas gingivalis) and Bacteroides intermedius (syn. Prevotella intermedia) isolated before and after treatment to amoxycillin with clavulanic acid remained unchanged.

Diagnosing periodontal diseases

At present, the diagnosis of periodontal disease requires a clinical evaluation of the patient including visual findings, the use of the periodontal probe, and radiographs. No test is available to evaluate disease activity. In specific cases, adjunctive procedures may also be useful. The identification of pathogenic microorganisms may aid in evaluating the periodontal status of special patients. However, these are not required for an adequate diagnosis of the common adult form of chronic periodontitis.

Microbial patterns in pooled subgingival plaque samples from young adults with advanced marginal periodontitis

Different bacterial profiles of subgingival plaque have been described for different clinical categories of marginal periodontitis. In the present investigation the subgingival microflora was studied in young adults with advanced marginal periodontitis. From 12 patients pooled subgingival plaque samples from 5 advanced stages of diseased sites were examined by direct differential phase-contrast microscopy and by cultivation on enriched and selective media. The proportions of the following genera and species were calculated: black-pigmented Bacteroides sp., B. gingivalis, Fusobacterium nucleatum, Veillonella sp., Actinobacillus actinomycetemcomitans, Capnocytophaga sp., Eikenella corrodens, Campylobacter sp., and Candida sp. Spirochete identification was carried out ultrastructurally. Calculated percent minimum similarity levels between the individuals revealed that each patient harbored its characteristic cultivable subgingival microflora different from the other individuals. The spirochetes seemed to constitute the subgingival bacterial group with the smallest variation as certain morphotypes were dominating in almost all individuals.

Darkground microscopy of subgingival plaque from the top to the bottom of the periodontal pocket

Part of the results of a study of subgingival plaque by darkground microscopy was used to investigate morphotype distribution at different levels within the periodontal pocket. Subgingival plaque was sampled at coronal, middle and apical levels from each of 28 approximal surfaces on 28 teeth extracted from 28 adults with untreated moderate to advanced periodontitis. Sample preparation and darkground microscopy were as described previously. The data recorded only the subgingival level at which the maximum count occurred for a given morphotype and subject. It was found that the maximum count of spirochaetes occurred most frequently at the apical level (p less than 0.05) and the maximum count of 'others' at the coronal level (p less than 0.05). Also, coccal counts showed a trend to increase the more apical the sample. Standardised darkground microscopy was able to show that the sampled subgingival level had a significant influence on plaque bacterial morphotype distribution, indicating the importance of accurate sampling of subgingival plaque at the most apical level.

The effectiveness of subgingival scaling and root planing. II. Clinical responses related to residual calculus

This study related 3-month clinical changes following scaling and root planning to the presence or absence of calculus on the root surfaces detected after extraction. Seven patients provided 646 sites evaluated for plaque, bleeding upon probing (BOP), probing pocket depth (PPD), and probing attachment level (PAL) at baseline and monthly following instrumentation. The teeth were extracted and evaluated for the presence and the percent surface area of calculus. Diagnostic sensitivity and predictability values for initial and residual PPDs, loss of PAL, and BOP in detecting residual calculus were determined. Calculus was found on 376 surfaces with a mean percent surface area of 3.13%. Predictability values were similar for all PPD ranges, while sensitivity decreased with increasing PPD. Probing attachment level changes were found to be unrelated to the presence or the amount of residual calculus. Bleeding upon probing had high levels of predictability, but sensitivity values were low. None of the clinical parameters evaluated in this study provided both a high level of predictability and sensitivity in detecting residual calculus.

Effects of adjunctive treatment of periodontitis with tetracycline and spiramycin

The present study was undertaken to compare the efficacy of two antibiotics, spiramycin and tetracycline, with a placebo when used adjunctively with scaling and root planing in the treatment of advanced adult chronic periodontitis. This was a double-blind, parallel, randomized trial with one factor (drug) at three levels. Ninety-six patients (mean age 46 +/- 1) were randomly assigned into one of three groups. All groups were scaled and root planed with each respective group receiving either spiramycin, tetracycline, or a placebo for 2 weeks. Two sites with probing depth of at least 7 mm were evaluated and the following clinical parameters were measured at baseline, 2, 8, 12, and 24 weeks: plaque index, bleeding on probing, crevicular fluid, probing depth, and change in the attachment level. The changes in the subgingival bacteria were monitored also using a differential staining technique. Seventy-nine patients completed the study. At the end of 24 weeks, although all three groups had shown clinical improvement when compared to the baseline data, there were no significant intergroup differences in any of the clinical parameters measured. While the proportion of spirochetes were significantly decreased (P less than 0.05) at 2- and 8-week intervals in both tetracycline and spiramycin groups (26% to 0.04% and 28% to 0.04%, respectively), compared to the placebo group (30% to 7%), only in the spiramycin group was the proportion of spirochetes significantly lower than the placebo group at the 24-week interval (3% and 11%, respectively). At week 24, the proportion of spirochetes in the tetracycline group had rebounded to 7%, which was not significantly different from the placebo group.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical effects of local application of collagen film-immobilized tetracycline

Tetracycline-containing cross-linked collagen film (TC film), or tetracycline-free placebo film, were locally applied 4 times, at 1-week intervals, to 33 teeth with periodontal pockets larger than 4 mm, in 11 patients with periodontal disease. The clinical and microbiological effects are summarized, as follows. In the group treated with the TC film, (1) the clinical indices were significantly decreased at the 4th and 7th weeks in comparison with those at the beginning of treatment. In particular, this group showed a significant decrease in the incidence of bleeding as compared with the placebo group at the 4th week. (2) Total counts of bacteria in the periodontal pockets showed an obvious tendency to decrease with time. The proportion of black-pigmented bacteroides was significantly decreased at the 4th and 7th weeks when compared with the pretreatment value. The extent of decrease in the proportion of spirochetes at both the 4th and 7th weeks was significant compared with the placebo group and the pretreatment value.

Clinical and microbiological effects of root debridement in periodontal furcation pockets

The aim of the present study was to investigate longitudinally over 52 weeks the clinical and microbiological effects of plaque control and root debridement at molar furcation sites. The results were compared with changes at non-molar sites. 24 non-molar sites and 31 grade II molar furcation sites with probing depth greater than or equal to 5.0 mm were monitored in 11 patients. Clinical measurements consisted of plaque scores, probing depths, and changes in probing attachment level. Microbiological monitoring was carried out with phase-contrast microscopy and anaerobic culturing. The debridement resulted in improvement in probing measurements and microbiological counts for both groups of sites. A slightly less favorable clinical response was noted for molar furcation sites. Higher post-operative microbiological counts were found throughout the 52-week observation period for molar furcation sites. Sites with probing attachment loss showed higher microbial counts and higher proportions of spirochetes, black pigmented colony forming units (CFU), and Bacteroides gingivalis CFU than sites with probing attachment gain. Individual site analysis, however, demonstrated marked variations of the microbiological counts at the different postoperative time points. In the few available sites undergoing probing attachment loss, no apparent association between target micro-organisms and periodontal deterioration was observed.

Effects of oral hygiene measures on clinical and microbiological parameters of periodontal disease

The effects of a 12-week period of oral hygiene alone on gingival conditions and subgingival microflora in 15 patients with severe periodontitis were investigated. Clinical measurements and plaque samples from selected sites were taken at week 0 (baseline), week 6, and week 12. Plaque samples were also taken at week 13, that is, 1 week following debridement. At week 0, the patients were instructed in supragingival plaque control and at week 6, the hygiene regimen was supplemented with the subgingival use of a toothpick device. At week 12, the patients received a full mouth supra- and subgingival debridement under local anesthesia. In those patients who complied with oral hygiene instructions (subgroup A), the gingival condition improved moderately while no improvement was found in less compliant patients (subgroup B). No significant changes were noted in the subgingival microflora in either subgroups A or B throughout the 12-week period of oral hygiene alone. However, significant reductions for all microbial parameters were found 1 week after debridement. Therefore, while moderate clinical improvements followed oral hygiene alone, no measurable changes in the subgingival microflora were observed concomitantly.

Susceptibility of small-sized oral spirochetes to eight antibiotics and chlorhexidine

The purpose of the study was to examine the susceptibility of two different small-sized spirochete morphotypes from subgingival plaque to eight antibiotics and chlorhexidine. MIC-values were determined by a broth dilution method and related to achievable antibiotic tissue- and blood concentrations. The spirochetes were characterized as susceptible, moderate susceptible, and resistant to the different antibiotics. The MICs of tetracycline hydrochloride, doxycycline, penicillin G, and chlorhexidine were all considerably lower for spirochete strains with a 2:4:2 endoflagella system (two endoflagella from each cell-end) than for strains with a 1:2:1 endoflagella system (one endoflagellum from each cell-end). No differences were observed for the remaining antibiotics. Spirochetes containing one endoflagellum from each cell-end were found to be susceptible to metronidazole and doxycycline, susceptible to moderate susceptible to tetracycline hydrochloride, moderate susceptible to penicillin G, and resistant to the remaining antibiotics. Spirochetes containing two endoflagella from each cell-end were susceptible to doxycycline, tetracycline hydrochloride, and metronidazole. Susceptible to moderate susceptible to penicillin G. These spirochetes were resistant to the remaining agents. The significance of these observations is discussed in relation to obtainable gingival crevicular fluid concentrations and treatment of marginal periodontitis.

Dark ground microscopy in relation to 3 clinical parameters of chronic inflammatory periodontal disease

This paper examines the relationships between 3 clinical parameters: pocket depth, gingival index, and bleeding index and 2 laboratory parameters: spirochaete counts and motility counts on the basis of analysis of 883 observations made in the mouths of 41 patients. The results were consistent with the findings of other studies in that deeper pockets tended to harbour higher %s of spirochaetes and motile organisms. The same overlap between all the parameters in general and between spirochaetes and pocket depth in particular as existed in our previous study was demonstrably evident. 8% of shallow pockets had spirochaete counts in excess of 20% and 79% of deep pockets had spirochaete counts of less than 20, 18% having no demonstrable spirochaetes. These results are consistent with those of our previous study and with the findings of Evian et al. that even in pockets of the order of 7 mm, the proportions of spirochaetes found varies from what may be expected at healthy sites to what may be expected at diseased sites.

False results associated with darkground microscopy of subgingival plaque

This study considers false results which may arise due to problems in the preparation or examination of specimens for darkground microscopy of subgingival plaque. Subgingival plaque samples obtained with a sterile curette were placed in 0.1-0.3 ml sterile full or 1/4 strength Ringer's solution: 0.85% saline, 1% gelatin in 0.85% saline, formal saline or pyrogen-free water for injection. Test slides were prepared from the original dispersion, and control slides from the corresponding sterile solution. Optimal dispersion solution, syringe dispersion frequency and the effect on motility of delay in processing samples were tested. Slides were also prepared from dispersions of 11 representative subgingival "periodontopathic" organisms. Problems in sampling included variability in counts between sites with comparable pocket depths, contamination of the sample and reduction of the sample volume after scaling. Problems in dispersion included contamination, uneven distribution of the different morphotypes and destruction of delicate organisms. Problems in slide preparation included slide contamination, limitation in the number of samples that can be assessed by one examiner at a given time without loss of activity of motile cells, and preparation of a cell monolayer. Problems in identification and counting included confusion of Brownian movements with motility, coccoid particles with cocci, spirochetes with campylobacter, flagella with flagella-like structures, size of cocci, counting of fragmented spirochetes and non-motile flagellated organisms and motile cells, and also bias in counting. Problems in morphotype grouping included the observation that many (10 of the 11 representative) periodontitis-related organisms were in the non-motile groups and not all cells of the motile species (Campylobacter, Capnocytophaga) showed motility. The results indicate that each stage of subgingival plaque darkground microscopy, sampling, dispersion, slide preparation, counting, morphotype grouping and interpretation may lead to false results if not representative or reproducible. Procedures are suggested for the minimisation of problems in the preparation and examination of subgingival plaque specimens for darkground microscopy.

Fluorescent antibody and flagella stains for rapid detection of bacteria at periodontally healthy and diseased sites

Two rapid methods of identifying bacteria associated with periodontal disease were investigated to determine their diagnostic usefulness in longitudinal or epidemiologic studies. Three nonmotile organisms were identified by fluorescent antibody stains (FA) while percentages of motile bacteria were assessed by counting all spirochetes, flagellated and nonflagellated organisms stained with a simplified silver-plating stain for flagella. Relationships between disease activity and these bacteria from subgingival plaque samples taken at 18 individual sites (12 diseased, 6 healthy) were determined by correlating the quantity of detectable bacteria with the Gingival Index (GI), Plaque Index (PLI) and probing depth (PD). The highest correlations found with the FA stains were between Bacteroides gingivalis and probing depth (rs = 0.85), GI (rs = 0.80) and PLI (rs = 0.80). Bacteroides melaninogenicus and/or Bacteroides intermedius also correlated well with the GI (rs = 0.66), PLI (rs = 0.64), and PD (rs = 0.59), but to a lesser degree than B. gingivalis. Flagella stains showed that spirochetes correlated highly with PD (rs = 0.82), as did the total motile group with PLI (rs = 0.82). Motile bacteria alone were only moderately associated with the clinical parameters measured. The results of this investigation suggest that FA- and flagella-staining methods can be valuable screening tools for the detection of bacterial species and motile organisms in longitudinal or epidemiologic studies.

Serum IgA and IgG antibodies to Treponema vincentii and Treponema denticola in adult periodontitis, juvenile periodontitis and periodontally healthy subjects

13 patients with untreated adult periodontitis (AP) were compared to 8 subjects free of periodontal disease (H) with respect to plaque index (PlI), gingival index (GI), probing depth (PD) and differential counts of subgingival bacterial morphotypes from a pooled sample of 6 surfaces with the greatest probing depth. Serum antibody levels to T. vincentii and T. denticola strains were also determined in these subjects as well as in the sera from 5 subjects with localized juvenile periodontitis (LJP). Subjects with AP had significantly elevated proportions of spirochetes and motile rods and lower proportions of coccoid cells than H subjects. They also exhibited significantly higher PlI and GI scores and greater probing depths. Antibody levels were normalized against a standard serum and expressed as ELISA units (EU). IgA and IgG antibody levels to all tested spirochete strains were significantly elevated in AP subjects as compared to subjects in group H or subjects with LJP. No significant differences in antibody titers were detectable between the H and LJP groups with respect to any of the tested strains. No significant correlation could be demonstrated between serum antibody titers to any of the oral spirochete strains tested and the proportions of oral spirochetes determined microscopically.

Subgingival microflora and periodontal conditions in healthy teenagers

The composition of subgingival flora was correlated with clinical periodontal conditions in 100 teenagers aged 12 to 17 years. The Community Periodontal Index of Treatment Needs (CPITN) was used for the clinical examination. Subgingival bacterial samples were taken from the mesial surface of each first molar, two samples for dark-field microscopy and two samples for Actinobacillus actinomycetemcomitans (A.a.) cultivation. Fifty-nine subjects had at least three healthy sextants. Score 1 was the highest CPITN recording in 61 subjects and Score 2 in 30 subjects. None had scores 3 or 4. In dark-field microscopy, cocci predominated in most samples. Straight rods, fusiforms and motile rods correlated negatively to the number of healthy sextants per subject. Straight rods and fusiforms showed a positive correlation to gingival bleeding tendency at the sampled site. A.a. was isolated in four subjects. Motile microorganisms and A.a. were detected rarely in subjects with good periodontal conditions.

Darkfield microscopy of subgingival plaque of an urban black population with poor oral hygiene

A low socio-economic community residing in Crossroads, Cape Town, consists of people who originated from the Eastern Cape areas of the Ciskei and Transkei. These individuals have had virtually no dental care, with the exception of emergency treatment for pain. A darkfield microscopic study of a random sample of 52 individuals was undertaken to determine the predominant morphological forms in the subgingival plaque of this population. Spirochetes were found to constitute 42.1% and motile rods, 7.7%, of the total darkfield microscopic count. Clinical assessment of the periodontal status of 100 individuals revealed the following mean values; plaque index (PI) = 1.44, gingival index (GI) = 1.31, probing depth (PD) = 2.35 mm and loss of attachment = 0.64 mm. Subgingival calculus deposits were present in 42% of the group and little or no mobility of the teeth was evident. Poor oral hygiene resulted in 90% of the tooth surfaces of the sampled population in Crossroads being covered with plaque, yet these individuals appear to be resistant to periodontitis. The high proportions of spirochetes and motile rods found in the subgingival plaque of this group were not indicative of periodontitis and therefore, fail to confirm the findings of other investigators.

The prevalence of spirochetes in the subgingival microbiota of Tanzanian and Dutch children

The subgingival microflora of 71 Tanzanian and 77 Dutch prepurberty children was analyzed by dark-field microscopy. Spirochetes were observed in almost every Tanzanian child and in 66% of the Dutch children. The predominant spirochetes were small and medium sized; large spirochetes were infrequently observed in the rural Tanzanian children and at the bleeding sites of the Dutch children. Further differences in the %s of cocci, rods and fusiforms indicated that the subgingival microflora of Tanzanian children is different from that of Dutch children. Generally, spirochetes occurred at higher %s and frequency at bleeding sites than at non-bleeding sites in both populations. However, the non-bleeding sites in the Tanzanian children had a higher prevalence of spirochetes than the bleeding sites in Dutch children. It is concluded that spirochetes are members of the normal flora of prepuberty children, that in children gingivitis is associated with increased proportions of spirochetes and that the presence of spirochetes in the gingival crevice is not dependent upon gingival inflammation.

The effects of a simplified mechanical oral hygiene regime plus supragingival irrigation with chlorhexidine or metronidazole on subgingival plaque

23 patients with pockets greater than or equal to 4 mm and evidence of bone loss on radiographs received thorough scaling and root planing followed by instruction in Bass brushing. They refrained from routine interdental cleaning for the first 28 days. A pulsating jet irrigator was used once daily supragingivally with 0.02% chlorhexidine (CH) 0.05% metronidazole (MD) or 0.01% quinine sulphate inactive control (PL), on a randomized double blind basis. Molar sites were not irrigated and served as control sites; they were only mechanically cleaned. For each patient, subgingival plaque samples were obtained from 2 test and 1 control sites at baseline (day 0), and on days 7, 28, 56 and 84. Plaque samples were monitored by darkfield microscopy on the basis of morphological characteristics of 4 types of bacteria: cocci, motile cells, spirochaetes and "others" (nonmotile rods, filaments and fusiforms). The simplified oral hygiene regime of scaling, root planing and Bass toothbrushing combined with interdental supragingival pulsating jet irrigation with CH, MD or PL appeared superior to a system of simplified oral hygiene alone, particularly during the first 4 weeks. However, at most time-points, the benefits were not statistically significant except for metronidazole. By day 84, the end of the experimental period, all groups approximated baseline levels. The results indicate that supragingival pulsated jet irrigation has limited effects on the composition of subgingival plaque. More marked changes occur when the irrigation fluid contains a chemical agent such as metronidazole known to be effective against important subgingival organisms, but probably not to such an extent as to change the composition of the flora from one associated with diseased sites to one associated with healthy sites.

A 7-month study of sulcular fluid flow in the assessment of healing after debridement of deep pockets

The purpose of this investigation was to assess the value of sulcular fluid flow (SFF) measurements in evaluation of the healing of deep periodontal pockets after scaling and root planing. Fourteen adult patients with advanced periodontal disease received supragingival prophylaxis and instructions in oral hygiene. Immediately after baseline examination, meticulous scaling and root planing were performed. One to five selected pockets per patient were monitored on Days 0, 30, 120 and 210. Subgingival microbial proportions, sulcular fluid flow, probing depth, Gingival Index and bleeding after probing were assessed and recorded. The subgingival microbial proportions were determined with darkfield microscopy. The periodontal conditions were markedly improved by Day 210 as depicted by the microbial proportions. The proportion of motile micro-organisms was reduced from 51% at baseline to 9% on Day 30. This result was sustained until Day 210. Healing was also evident from the changes in Gingival Index scores and bleeding after probing. Probing depth was reduced from a mean of 8.3 to 4.5 mm. Correlations between the individual means recorded for the clinical parameters and bacterial proportions were calculated for the pooled data of all four examinations. Sulcular fluid flow did not correlate with the clinical parameters. Gingival Index, bleeding after probing or probing depth. The latter three parameters correlated significantly with the microbial proportions and each other. When the pooled tooth surface recordings of Days 30, 120 and 210 were divided into two groups according to the proportion of motile bacteria (the groups with less than 18% of spirochetes and motile rods and the groups with greater than 18% of spirochetes and motile rods), a significant difference in the mean amount of sulcular fluid flow (P less than 0.01) and mean probing depth (P less than 0.001) could be demonstrated between the two groups.