The effect of short-term administration of minocycline HCl on gingival inflammation and subgingival microflora

Clinical and microbiological effects of adjunctive local delivery of minocycline (Periocline®) in patients receiving supportive periodontal therapy: a pilot study

Purpose

This study aimed to evaluate the clinical and microbiological efficacy of adjunctive local delivery of minocycline (Periocline^®) in patients receiving supportive periodontal therapy (SPT) after initial treatment.

Methods

The participants were 16 men and 8 women (age, 20–65 years) who had at least 15 natural teeth, underwent SPT for more than 1 year due to chronic periodontitis, had 4 or more periodontal pocket sites deeper than 5 mm, and showed >25% gingival bleeding on probing (BoP). They were randomly assigned to the test and control groups. In the test group, mechanical debridement and local antibiotic delivery were performed for all periodontal sulci/pockets; in the control group, mechanical debridement and saline irrigation were performed. In patients who underwent SPT for more than 1 year, clinical and microbiological examinations were performed at baseline and 1 and 3 months after SPT. The clinical examination included an assessment of the periodontal pocket depth, clinical attachment level, plaque index, and BoP. Microbial tests were performed using real-time polymerase chain reaction; the relative ratios of Porphyromonas gingivalis and Fusobacterium nucleatum were determined.

Results

Both groups showed significant improvements in clinical parameters at 1 and 3 months from baseline; there were no significant changes between months 1 and 3. Intergroup differences were insignificant. The microbiological analysis revealed no significant differences in P. gingivalis and F. nucleatum ratios across time points. While intergroup differences were insignificant, there was a tendency for the P. gingivalis and F. nucleatum ratios to decrease in the test group.

Conclusions

Mechanical debridement in patients receiving maintenance therapy resulted in clinically significant improvement; the effectiveness of additional local delivery of antibiotics was not significant. The ratios of P. gingivalis and F. nucleatum showed a tendency to decrease in the test group, although it was not significant.

Current concepts and an alternative perspective on periodontal disease

BACKGROUND

Epidemiological data from countries worldwide show a consistent pattern implying that a fraction of around 10% of those over 40-50 years in all populations will exhibit severe periodontitis with the potential risk of losing teeth during their life-time. The subgingival microbiota shows striking similarities between populations irrespective of disease severity and can only marginally explain the clinical pattern. It is also difficult to explain this pattern by genetic and acquired risk factors such as systemic disease (e.g. diabetes) or habits (e.g. smoking) even if they may have a confounding effect on the disease.

MAIN TEXT

Inflammation of the gingiva appears to be a normal and physiological response to the presence of commensal bacteria along the gingival crevice and in the dental biofilm. Over many years of exposure to the dental biofilm, the chronic inflammation in the gingiva gradually results in a loss of attachment and bone loss. Numerous laboratory and clinical studies have provided insight into the potential role of determinants that are associated with periodontitis. However, it has been difficult to relate the findings to the pattern of the distribution of the disease observed in epidemiological studies. We propose a simple and parsimonious model that considers all the multitude of potential determinants as creating effectively random noise within the dental biofilm to which the tissues react by accumulating the effects of this noise.

CONCLUSIONS

We suggest that such a model can explain many of the epidemiological features of periodontal breakdown over time, and we discuss its clinical implications.

Long-term evaluations of teeth and dental implants during dental maintenance period

PURPOSE

This study was designed to evaluate the teeth and dental implants during dental maintenance therapy over 3 years in different conditions after periodontal and dental prosthetic treatment.

MATERIALS AND METHODS

166 patients received maintenance therapy. 59 patients were treated with 2% minocycline-HCl ointment as local drug delivery (LDD) (L group) and 107 patients were treated without LDD (NL group). Clinical data was collected in maintenance period for evaluation. Patients were classified into groups depending on the application of LDD with maintenance therapy, the type of dental treatment before maintenance period (Pre-Tx), the frequency (F-MT), and regularity (R-MT) of maintenance therapy.

RESULTS

The numbers of lost teeth (N-teeth, P=.003) and newly placed dental implants (N-implants, P=.022) are significantly different according to Pre-Tx. F-MT among patients who received surgical dental treatment before maintenance period showed statistical differences in N-teeth (P=.041), but not in N-implants (P=.564). All of the patients in L group showed high F-MT (F-MT1). In NL group, there were no statistical differences in N-teeth or N-implants according to F-MT or R-MT. In F-MT1 group, application of LDD made N-teeth significantly different from both Pre-Tx groups while no significant difference could be found in N-implant. Independent t-test and one-way ANOVA were selected for statistical analysis.

CONCLUSION

The regular maintenance therapy and LDD can be effective for teeth during maintenance period. It is not only pharmacological efficacy in decreasing bacterial species that makes LDD a useful adjunct. Application of LDD also motivates patients to take adequate check-ups in the aspects of both frequency and regularity.

Mechanisms of action of systemic antibiotics used in periodontal treatment and mechanisms of bacterial resistance to these drugs

Antibiotics are important adjuncts in the treatment of infectious diseases, including periodontitis. The most severe criticisms to the indiscriminate use of these drugs are their side effects and, especially, the development of bacterial resistance. The knowledge of the biological mechanisms involved with the antibiotic usage would help the medical and dental communities to overcome these two problems. Therefore, the aim of this manuscript was to review the mechanisms of action of the antibiotics most commonly used in the periodontal treatment (i.e. penicillin, tetracycline, macrolide and metronidazole) and the main mechanisms of bacterial resistance to these drugs. Antimicrobial resistance can be classified into three groups: intrinsic, mutational and acquired. Penicillin, tetracycline and erythromycin are broad-spectrum drugs, effective against gram-positive and gram-negative microorganisms. Bacterial resistance to penicillin may occur due to diminished permeability of the bacterial cell to the antibiotic; alteration of the penicillin-binding proteins, or production of β-lactamases. However, a very small proportion of the subgingival microbiota is resistant to penicillins. Bacteria become resistant to tetracyclines or macrolides by limiting their access to the cell, by altering the ribosome in order to prevent effective binding of the drug, or by producing tetracycline/macrolide-inactivating enzymes. Periodontal pathogens may become resistant to these drugs. Finally, metronidazole can be considered a prodrug in the sense that it requires metabolic activation by strict anaerobe microorganisms. Acquired resistance to this drug has rarely been reported. Due to these low rates of resistance and to its high activity against the gram-negative anaerobic bacterial species, metronidazole is a promising drug for treating periodontal infections.

Clinical and biochemical efficacy of minocycline in nonsurgical periodontal therapy: a randomized controlled pilot study

The present study evaluated the effects of systemic minocycline on clinical and biochemical parameters of chronic periodontitis, which is a common inflammatory disorder of the periodontium initiated by the presence of bacteria in the gingival sulcus. Besides nonsurgical periodontal therapy, 20 individuals received minocycline systemically while another 20 subjects received placebo capsules for 2 weeks. Plaque index (PI), sulcus bleeding index (SBI), probing depth (PD), and relative attachment level (RAL) were measured and gingival crevicular fluid (GCF) samples were obtained at baseline and first, third, and sixth months. Matrix metalloproteinase-8 (MMP-8) and prostaglandin E₂ (PGE₂) levels were analyzed by enzyme immunoassay method. Significant improvements in all parameters in both groups were recorded. In the minocycline group, changes in PI and SBI were significantly greater only at first month, whereas reductions in PD, RAL, MMP-8, and PGE₂ levels were greater at all times. MMP-8 and PGE₂ exhibited positive correlations with SBI, PD, and each other. Minocycline demonstrated clinical benefit for periodontal therapy and provided further improvements on inflammatory mediators promising a host-modulating capacity.

In vitro minocycline activity on superinfecting microorganisms isolated from chronic periodontitis patients

Chronic periodontitis is the most common type of periodontitis and it is associated with various species of microorganisms. Enteric rods, Pseudomonas, Staphyloccocus and Candida have been retrieved from periodontal pockets of patients with chronic periodontitis and correlated to cases of superinfection. Local or systemic antibiotic therapy is indicated to reinforce the effects of the conventional mechanical therapy. Minocycline has been suggested as one of the most effective drugs against periodontal pathogens. The aim of this work was to evaluate the minimal inhibitory concentration (MIC) of minocycline on superinfecting microorganisms isolated from the periodontal pocket and the oral cavity of individuals with chronic periodontitis. Isolates of Enterobacteriaceae (n = 25), Staphylococcus spp. (n = 25), Pseudomonas aeruginosa (n = 9) and Candida spp. (n = 25) were included in the study. Minimal inhibitory concentrations (MIC) of minocycline were determined using the Müeller-Hinton agar dilution method. Staphylococcus spp. isolates were the most sensitive to minocycline with a MIC of 8 µg/mL, followed by Enterobacteriaceae with a MIC of 16 µg/mL. The concentration of 16 µg/mL inhibited 96% of Candida spp. isolates. The MIC for 88.8% of the isolates of Pseudomonas aeruginosa was 128 µg/mL. A concentration of 1,000 µg/mL was not enough to inhibit 100% of the tested isolates.

Tetracycline analogues (doxycycline and COL-3) induce caspase-dependent and -independent apoptosis in human colon cancer cells

Tetracycline analogues (TCNAs) possess cytotoxic activities as well as matrix metalloproteinase (MMP) inhibitory properties. Previously, we demonstrated that doxycycline (DOXY) could induce apoptosis in human HT29 colon cancer cells. In present study, the molecular apoptotic mechanisms induced by two kinds of TCNAs, designated as DOXY and COL-3 (chemically modified tetracycline-3; 6-demethyl, 6-deoxy, 4-dedimethylamino tetracycline), were evaluated in cultured HT29 cells. Both TCNAs inhibited the proliferation of 6 different colorectal cancer cell lines in a dose-dependent manner. Especially, COL-3 had a stronger effect on cancer cells than DOXY. Apoptotic changes were actually observed by 10 mug/ml COL-3 and 20 mug/ml DOXY in a time-dependent manner. COL-3 produced the increase in cytosolic cytochrome c and the loss of mitochondrial membrane potential after 3 hr treatment, and thereafter activated caspases. In case of DOXY, these changes were observed after 24 hr. Bax translocation was not a prerequisite for cytochrome c releasing in COL-3 treatment. Pretreated pancaspase inhibitor (Z-VAD-FMK) reduced COL-3 and DOXY mediated apoptosis up to 81.3 and 35.3%, as compared with nontreated cells, respectively. These data indicated that TCNAs could induce mitochondria-mediated apoptosis through both caspase-dependent and -independent pathway. In fact, endonuclease G and apoptosis-inducing factor were released into cytosol after the treatment of TCNAs, which indicated that caspase-independent apoptotic pathway is also one of the key mechanisms for the treatment of TCNAs. Taken together, we believe that TCNAs could have strong potentials for clinical application in treating colorectal cancers and improve cancer chemotherapy.

Viruses in periodontal disease - a review

The purpose of this review was to evaluate the evidence supporting the hypothesis that viral infection plays a role in the development of periodontitis. An involvement in periodontal diseases has been suspected specifically for human immunodeficiency virus (HIV) and herpes viruses. An association has been demonstrated between HIV infection and some distinct forms of periodontal infection, i.e. necrotizing lesions. Furthermore, reports of increased prevalence and severity of chronic periodontitis in HIV-positive subjects suggests that HIV infection predispose to chronic periodontitis. Several studies, most of them from the same research group, have demonstrated an association of herpesviruses with periodontal disease. Viral DNA have been detected in gingival tissue, gingival cervicular fluid (GCF) and subgingival plaque from periodontaly diseased sites. In addition markers of herpesviral activation have been demonstrated in the GCF from periodontal lesions. Active human cytomegalovirus (HCMV) replication in periodontal sites may suggest that HCMV re-activation triggers periodontal disease activity. Concerns regarding sampling, methods and interpretation cast doubts on the role of viruses as causes of periodontal disease.

A comparative evaluation of the clinical effects of systemic and local doxycycline in the treatment of chronic periodontitis

In this study, the clinical efficacies of systemic doxycycline (SD) and local doxycycline (LD) in the treatment of chronic periodontitis were compared. Forty-five patients were studied in 3 main groups with 5 treatments: SD alone, SD+scaling-root planing (SD+SRP), LD alone, LD+SRP and SRP alone. Antibiotic-treated patients were given doxycycline treatment alone in 1 quadrant of their upper jaws, and doxycycline+SRP was given in the contralateral quadrant. The areas included at least 4 teeth with > or = 5 mm pockets. Probing depth (PD), clinical attachment level, gingival index, sulcular bleeding index and plaque index values were recorded at baseline and the 7th week. The results were statistically analyzed. All of the clinical parameters were significantly reduced by all treatments (P < or = 0.05). The SD and LD treatments alone provided significant clinical healings. The significant differences among the groups were only in PD at the 7th week. The LD treatment provided significantly higher PD reduction than the SD treatment (P < or = 0.05). No significant difference was found between the SD+SRP and the LD+SRP treatments. There was no significant difference between SD+SRP and SRP alone treatment (P > 0.05). The SD group showed lower PD reduction than SRP group (P < or = 0.05), while no significant difference was found between LD and SRP treatments. The LD alone treatment seemed more effective than SD alone treatment on PD reduction, but no significant difference was found between them when combined with the SRP. LD may be more preferable than SD as an adjunct to mechanical treatment since LD seems more effective than SD on PD reduction and does not have the side effects of SD.

A systematic review on the effect of systemic antimicrobials as an adjunct to scaling and root planing in periodontitis patients

BACKGROUND

Scaling and root planing (SRP) are the bases of non-surgical therapy in the treatment of periodontitis. However, results from this therapy are often unpredictable and dependable from many different factors.

OBJECTIVES

The aim of this systematic review was to evaluate the effectiveness of the adjunctive use of systemic antimicrobials with scaling and root planing (SRP) vs. SRP alone in the treatment of chronic (CP) or aggressive periodontitis (AgP).

SEARCH STRATEGY

Use of computerized databases, namely MEDLINE, the Cochrane Oral Health Group Specialty Trials Register and EMBASE; reference lists from relevant articles were hand-searched; and a hand-search of selected journals until April 2001.

SELECTION CRITERIA

Studies were selected if they were designed as controlled clinical trials in which systemically healthy patients with either AgP or CP were treated with SRP plus systemic antimicrobials in comparison with SRP alone or with placebo, for a minimum of 6 months. Main outcome measures were clinical attachment level (CAL) change and probing pocket depth (PPD) change.

DATA COLLECTION AND ANALYSIS

Two reviewers extracted independently information regarding quality and study characteristics, in duplicate. Kappa scores determined their agreement. Main results were collected and grouped by drug, disease and PPD category. For the quantitative data synthesis, the data was pooled (when mean differences and standard errors were available), and either a Fixed Effects or Random Effects meta-analysis was used for the analysis.

RESULTS

After an initial selection, 158 papers were identified by the manual and electronic searches; 25 papers were eligible for inclusion. Their quality assessment showed that randomization and allocation concealment methods were seldom reported and blindness was usually not defined clearly. In general, selected studies showed high variability and lack of relevant information for an adequate assessment. Overall, SRP plus systemic antimicrobial groups demonstrated better results in CAL and PPD change than SRP alone or with placebo groups. Only limited meta-analyses could be performed, due to the difficulties in pooling the studies and the lack of appropriate data. This analysis showed a statistically significant additional benefit for spiramycin (PPD change) and amoxicillin/metronidazole (CAL change) in deep pockets.

CONCLUSION

Systemic antimicrobials in conjunction with SRP, can offer an additional benefit over SRP alone in the treatment of periodontitis, in terms of CAL and PPD change, and reduced risk of additional CAL loss. However, differences in study methodology and lack of data precluded an adequate and complete pooling of data for a more comprehensive analyses. It was difficult to establish definitive conclusions, although patients with deep pockets, progressive or 'active' disease, or specific microbiological profile, can benefit more from this adjunctive therapy.

Effect of repeated local minocycline administration on periodontal healing following guided tissue regeneration

BACKGROUND

Infection after a periodontal surgical site has been prepared for guided tissue regeneration (GTR) is one of the common complications that can compromise healing. The purpose of this study was to assess the effect of repeated local antimicrobial therapy following GTR for improving clinical attachment gains, and to histologically evaluate the various cell populations and bacterial contamination of the retrieved expanded polytetrafluoroethylene membrane (ePTFE).

METHODS

Forty periodontal intrabony defects in 40 patients were treated by a flap procedure that included the use of ePTFE membranes to allow GTR. Patients were randomly assigned to 2 treatment groups: 20 patients were treated with the ePTFE alone (control group), and the other 20 were treated with the ePTFE combined with the administration of a weekly repeated local application of minocycline ointment for 8 weeks after membrane placement (test group). The membranes were retrieved 6 weeks after the initial surgery and sectioned serially in a coronal-apical plane. The sections were then divided into 9 fields and examined by light microscopy for the presence of inflammatory cells and oral bacteria. Clinical measurements were taken at the time of baseline examination and at a 6-month follow-up examination after removal of the ePTFE.

RESULTS

At the 6-month follow-up examination, control and test groups showed significant improvement; i.e., reduction in the probing depth and increased clinical attachment gain compared with the values at the baseline examination. However, the mean clinical attachment gain of the test group (3.0+/-0.3 mm) was significantly (P = 0.03) greater than that of the control group (2.0+/-0.5 mm). Histologically, the total number of the cells of both groups was similar. In both groups, mononuclear cells were dominant and fibroblasts, neutrophils, and plasma cells were rarely encountered. There was a tendency for the number of macrophages to be somewhat higher in the control group. The total number of bacteria in the test group was significantly less than that in the control group. The number of bacteria in both control and test groups decreased toward the apical portion.

CONCLUSIONS

In the present study, clinical attachment gain of intrabony defects following GTR was favorable with repeated local administration of minocycline ointment. However, a complete microbial eradication was not achieved.

Systemic doxycycline administration in the treatment of periodontal infections (II). Effect on antibiotic resistance of subgingival species

The purpose of this investigation was to determine the proportion and prevalence of doxycycline resistant species in subgingival plaque samples taken during and after doxycycline administration. 20 subjects with adult periodontitis were randomly assigned to test (n = 10) or control groups (n = 10). Saliva samples as well as subgingival plaque samples taken from the distal surface of 6 posterior teeth were collected at baseline. All subjects received full mouth SRP and the test group systemic doxycycline at the dosage of 100 mg/day for 14 days. Saliva samples and plaque samples from the distal surface of 2 randomly selected teeth were taken at 3, 7 and 14 days during and after antibiotic administration. Control subjects were sampled at the same time points. Samples were anaerobically dispersed and serially diluted in PRAS Ringer's solution and plated on enriched Trypticase soy blood agar plates with or without 4 microg/ml doxycycline. After 7 days of anaerobic incubation, colonies were counted on both sets of plates. Microbial growth was washed from the doxycycline-containing media and the species identified using 40 DNA probes and checkerboard DNA-DNA hybridization. Differences in proportions of resistant species between test and control groups were tested for significance at each time point using the Mann Whitney test and over time within each group using the Quade test. The mean % (+/-SEM) of isolates resistant to 4 microg/ml doxycycline in the plaque samples of the test subjects increased from 6+/-2 to 48+/-9% during doxycycline administration, decreasing to 25+/-6% 2 weeks later and 9+/-2% at 90 days. In saliva, the % of resistant isolates rose from 13+/-1% to 81+/-10% during doxycycline administration falling to 46+/-8% 2 weeks later and 22+/-5% at 90 days. The % of resistant isolates did not change significantly in plaque or saliva samples of the control subjects at the same time points. For all subject visits combined, the most prevalent resistant species were: Streptococcus anginosus, Streptococcus oralis, Streptococcus intermedius, Streptococcus sanguis, Streptococcus mitis, Veillonella parvula, Actinomyces gerencseriae, Streptococcus constellatus, Actinomyces naeslundii genospecies 2, Streptococcus gordonii, Eikenella corrodens and Actinomyces naeslundii genospecies 1. Doxycycline resistant strains of these species were detected in both plaque and saliva samples prior to therapy and in the control group. Despite the finding of increased resistance, approximately 50% of the organisms present at periodontal sites at the end of 14 days of doxycycline administration tested sensitive to the agent.

Doxycycline induces Fas/Fas ligand-mediated apoptosis in Jurkat T lymphocytes

Tetracyclines have been used in the treatment of chronic inflammatory diseases associated with local infiltration of inflammatory cells and matrix destruction as observed in rheumatoid arthritis and periodontal disease. Fas/Fas ligand (FasL)-mediated apoptosis plays an important role in maintaining T lymphocyte homeostasis and modulating immune response. The present study demonstrates that doxycycline inhibits Jurkat T lymphocyte proliferation and induces apoptosis. The phytohemagglutinin (PHA)-activated Jurkat cells are more susceptible to doxycycline-induced apoptosis. Furthermore, doxycycline-induced apoptosis is associated with increased Fas/FasL expression in Jurkat cells. The increase of apoptosis in Jurkat cells treated with doxycycline is consistent with the increase of FasL expression. These results suggest that doxycycline may downregulate the inflammatory process in certain diseases by eliminating activated T lymphocytes through Fas/FasL-mediated apoptosis.

A 15-month evaluation of the effects of repeated subgingival minocycline in chronic adult periodontitis

BACKGROUND

A double-blind, randomized, parallel, comparative study was designed to evaluate the long-term safety and efficacy of subgingivally administered minocycline ointment versus a vehicle control.

METHODS

One hundred four patients (104) with moderate to severe adult periodontitis (34 to 64 years of age; mean 46 years) were enrolled in the study. Following scaling and root planing, patients were randomized to receive either 2% minocycline ointment or a matched vehicle control. Study medication was administered directly into the periodontal pocket with a specially designed, graduated, disposable applicator at baseline; week 2; and at months 1, 3, 6, 9, and 12. Scaling and root planing was repeated at months 6 and 12. Standard clinical variables (including probing depth and attachment level) were evaluated at baseline and at months 1, 3, 6, 9, 12, and 15. Microbiological sampling using DNA probes was done at baseline; at week 2; and at months 1, 3, 6, 9, 12, and 15.

RESULTS

Both treatment groups showed significant and clinically relevant reductions in the numbers of each of the 7 microorganisms measured during the entire 15-month study period. When differences were detected, sites treated with minocycline ointment always produced statistically significantly greater reductions than sites which received the vehicle control. For initial pockets > or =5 mm, a mean reduction in probing depth of 1.9 mm was seen in the test sites, versus 1.2 mm in the control sites. Sites with a baseline probing depth > or =7 mm and bleeding index >2 showed an average of 2.5 mm reduction with minocycline versus 1.5 mm with the vehicle. Gains in attachment (0.9 mm and 1.1 mm) were observed in minocycline-treated sites, with baseline probing depth > or =5 mm and > or =7 mm, respectively, compared with 0.5 mm and 0.7 mm gain at control sites. Subgingival administration of minocycline ointment was well tolerated.

CONCLUSIONS

Overall, the results demonstrate that repeated subgingival administration of minocycline ointment in the treatment of adult periodontitis is safe and leads to significant adjunctive improvement after subgingival instrumentation in both clinical and microbiologic variables over a 15-month period.

The use of locally delivered minocycline in the treatment of chronic periodontitis. A review of the literature

Tetracyclines are frequently used in the treatment of periodontitis; however, emergence of resistant bacterial strains has decreased the utility of these drugs. At present, there are a lot of data in the literature from which one can draw conclusions regarding the use of local drug delivery. This paper reviews the utility and different systems of local delivery of minocycline, a semisynthetic tetracycline, in the treatment of periodontitis.

Clinical and microbiological effects of minocycline-loaded microcapsules in adult periodontitis

Clinical and microbiological effects of subgingival delivery of 10% minocycline-loaded (MC), bioabsorbable microcapsules were examined in 15 adult periodontitis patients. Patients received oral hygiene instruction 2 weeks prior to the study. At baseline (day 0) all teeth received supragingival scaling (SC); 2 quadrants received no further treatment and 1 quadrant received subgingival scaling and root planning (SRP). In the fourth quadrant, the tooth with the deepest probing sites (at least 1 site > or = 5 mm) was treated with minocycline microcapsules. The sites were evaluated at baseline and weeks 1, 2, 4, and 6. Clinical indices included bleeding on probing (BOP), probing depths (PD), and attachment loss (AL). Microbiological evaluations included percent morphotypes by phase-contrast microscopy; cultivable anaerobic, aerobic, and black-pigmented Bacteroides (BPB); and percent Porphyromonas gingivalis, Prevotella intermedia, Eikenella corrodens, and Actinomyces viscosus by indirect immunofluorescence. In the SC + MC group, BOP, PD, and AL were significantly reduced from baseline for weeks 1 to 6. BOP in the SC + MC group was significantly reduced compared to the SRP group from weeks 2 to 6. In the SC + MC group the percent of spirochetes and motile rods decreased and the percent of cocci increased after 1 week. The increased cocci and decreased motile rods were statistically greater at weeks 4 and 6 in the SC + MC group compared to the SRP group. This study demonstrates that local subgingival delivery of 10% minocycline-loaded microcapsules as an adjunct to scaling results in reduction in the percent sites bleeding on probing greater than scaling and root planning alone and induces a microbial response more favorable for periodontal health than scaling and root planing.

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.

Evaluation of the long-term efficacy and safety of locally-applied minocycline in adult periodontitis patients

The objectives of the present study were to establish in a long-term investigation the safety as well as the clinical and microbiological efficacy of scaling and rootplaning combined with local application of 2% minocycline hydrochloride-gel versus placebo-gel in patients with moderate to severe chronic adult periodontitis. This was an 18 months, randomized, double-blind, parallel, comparative study, in which 20 healthy patients with moderate to severe chronic periodontitis participated. At baseline, all patients received professional oral hygiene-instruction and supra- and subgingival scaling and root planing. The minocycline-gel was applied subgingivally baseline, 2 weeks, 1, 3, 6, 9 and 12 months. Microbiological evaluation was carried out using DMDx to identify the following bacteria: Porphyromonas gingivalis, Prevotella intermedia, Actinobacillus actinomycetemcomitans, Campylobacter rectus, Fusobacterium nucleatum and Treponema denticola. In addition standard microbiological techniques were used for the detection of P. gingivalis, P. intermedia, P. micros, A. actinomycetemcomitans, C. rectus, F. nucleatum, C. albicans and Enterobacteriaceae. Results showed a statistically significant improvement for all clinical parameters irrespective of the treatment modality. No differences were observed between test and control with regard to probing depth and attachment level. The DMDx data showed a significant reduction in both the numbers and the prevalence over the 15 months period, but no significant difference between groups. Culture data showed that at baseline two-third were positive for P. gingivalis and P. intermedia. Analysis over the 18 month period showed no significant difference between the two treatment modalities. C. albicans and Enterobacteriaceae were detected only in small proportions at each time interval in a limited number of patients. No adverse reactions were observed during the trial period. The present patient group responded favourably to scaling and rootplaning, but did not benefit from an effect of local of minocycline. Subgingival debridement in combination with oral hygiene instruction by itself has been shown to be effective. It remains to be studied whether local application of minocycline can be effective as an adjunct to mechanical therapy in sites that respond poorly to conventional treatment.

Inhibition of the migration, attachment, spreading, growth and collagen synthesis of human gingival fibroblasts by arecoline, a major areca alkaloid, in vitro

Because betel quid (BQ) chewing has been linked to a higher prevalence of periodontal diseases, the pathobiological effects of arecoline, a main alkaloid found in areca nut, were investigated in cultured human gingival fibroblasts. At concentrations higher than 0.4 mM, arecoline inhibits cell attachment, cell spreading and cell migration in a dose-dependent manner. These inhibitory effects were associated with intracellular depletion of glutathione (GSH). At concentrations of 0.4 mM and 1 mM, arecoline depleted about 26% and 45% of GSH after 2 h incubation. Exposure of cells to arecoline at concentrations lower than 0.4 mM for 2 h showed no significant decrease in either cell viability or intracellular GSH. However, incubation of cells for 24 h in 1 mM are colined decreased the cell numbers to only 35% of those in the untreated control. Arecoline also decreased cell growth and collagen synthesis in a dose-dependent manner. Because of repeated and long-term exposure to arecoline, BQ chewers could be more susceptible to periodontal damage and less responsive to new attachment procedures.

Efficacy of systemically administered acetylsalicylic acid plus scaling on periodontal health and elastase-alpha 1-proteinase inhibitor in gingival crevicular fluid

The purpose of this proof of principle trial was to assess whether conventional periodontal therapy and systemically administrated acetylsalicylic acid (ASA) are functionally synergistic when combined in the treatment of periodontitis. A total of 30 patients with untreated moderate to severe adult periodontitis were enrolled into the study and were given placebo q.i.d. between the baseline and 6-week examination, and acetylsalicylic acid (ASA) 500 mg q.i.d. between the 6-week and 12-week examinations. In addition, they received supra- and subgingival scaling in 1 quadrant after baseline examination and in 2 further randomly selected quadrants after the 6-week examination. The study design resulted in the following 4 therapies: (1) scaling plus ASA 500 mg q.i.d.; (2) scaling plus placebo q.i.d.; (3) ASA 500 mg q.i.d. alone; (4) placebo q.i.d. alone. Two-way analysis of variance showed functional synergism of ASA and scaling, resulting in a therapeutic efficacy approximately equivalent to the sum of each individual therapeutic efficacy (i.e., ASA alone and scaling alone) in reducing gingival inflammation and pocket probing depth over the 6-week observation period (interaction: p > 0.05). Only the effect of ASA was significant in reducing the concentration of elastase-alpha 1-proteinase inhibitor in gingival crevicular fluid (GCF E-alpha 1-PI) (p < 0.001), reduction in GCF E-alpha 1-PI concentrations by ASA may indicate a decreased risk in periodontal disease progression. The results suggest that the combination of therapies and their different mechanisms of action, i.e., reduction of bacterial plaque and inhibition of destructive components of the immune responses, may result in functionally synergistic therapeutic efficacies in patients with untreated adult periodontitis.

The effect of non-surgical periodontal and adjunctive minocycline-HCL treatments on the activity of salivary proteases

The purpose of this investigation was to evaluate the effect of non-surgical periodontal treatment and adjunctive systemic minocycline therapy on the level of neutral protease activity in whole saliva of adults with periodontitis. A test group of 21 adult patients with moderate to severe periodontitis was compared to a control group of 5 adults with healthy periodontium. Four test groups were examined: 1) scaling and root planing (SRP), probing depth = 4 to 5 mm; 2) SRP, PD > or = 6 mm; 3) SRP and adjunctive systemic minocycline therapy, PD = 4 to 5 mm; 4) SRP and adjunctive systemic minocycline therapy, PD > or = 6 mm. Clinical parameters and levels of neutral protease in whole saliva were assessed at baseline and on the sixth week after the non-surgical periodontal treatment. Neutral protease activity was measured by spectrofluorimetric method. Statistical tests of Mann-Whitney and Spearman Rank correlation coefficient were used in the evaluation of the mean values of measurements. The mean values of protease activity were significantly higher in the test groups than in the control group at baseline. Six weeks after non-surgical therapy, patients with 4 to 5 mm probing depth had approximate values of protease activity comparable to the control group. Hence it can be argued that these patients did not need minocycline HCL as an adjunctive therapy. However, non-surgical therapy had limited effects on both clinical parameters and enzyme activities for subjects with > or = 6 mm probing depth; on the other hand, gingival inflammation and enzyme activities were reduced significantly by the usage of minocycline as adjunctive therapy in these patients. According to our results, neutral protease activity in saliva is related to probing depth and gingival bleeding index, and not related to age and epithelial cell number. For these reasons, systemic minocycline therapy might be useful as an adjunct to non-surgical therapy in the presence of deep pockets, especially for reinfected cases. Further investigations are needed to confirm this suggestion.

Bacterial resistance following subgingival and systemic administration of minocycline

The aim of the present study was to compare total numbers of cultivable bacteria and prevalence of resistance to minocycline among periodontal bacteria following subgingival or systemic application of minocycline in patients suffering from periodontal disease. 10 adult patients were administered 2% minocycline ointment subgingivally into their periodontal pockets at baseline, week 2 and months 1, 3, 6 and 9. Patients had scaling/root planing at baseline and month 6. In addition, 10 patients undergoing scaling/root planing followed by a 10-day course of systemic minocycline therapy, were studied and compared with the subgingival application group. Bacterial samples were taken from the 4 deepest pockets before each subgingival application of the drug. The systemic administration group was sampled at baseline and at week 2, as well as months 1 and 3 after completing the antibiotic treatment. For each patient at each sampling, bacterial samples were pooled, diluted, seeded on parallel blood agar plates and incubated aerobically and anerobically. After incubation, 30 colonies were picked at random and transferred to blood agar plates supplemented with 10 micrograms/ml minocycline, to estimate prevalence of minocycline-resistant bacteria. The results of this study indicate that subgingival application of minocycline ointment resulted in an initial reduction in total numbers of cultivable bacteria, which then remained depressed during the full year of the study. No such observation was made in the systemic administration. Both in the subgingival and the systemic administration group, the % of cultivable aerobic and anaerobic minocycline-resistant bacterial strains increased transiently following administration of the drug, but returned to baseline levels within 3 months post-treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacological control of periodontal disease. II. Antimicrobial agents

Antimicrobial agents are of value in the management of certain types of periodontal disease, notably early onset, juvenile and refractory periodontitis. The diagnosis of these conditions is often made on clinical grounds but microbial sampling of the pocket flora is of value in determining the type of antimicrobial therapy. Routine systemic use of these drugs in the management of chronic adult periodontitis is contraindicated, and is no substitute for root surface debridement and thorough supragingival plaque control. Tetracyclines and metronidazole are the agents most frequently used in the management of periodontal disease. Both drugs can be given systemically or applied topically into the periodontal pocket. The latter route is preferred since the dose is reduced considerably, but the local tissue concentration is increased. The efficacy of local drug delivery is dependent upon the release kinetics of the drug from the delivery vehicle. Although local application can be time consuming, it reduces the risk of adverse reactions and drug interactions. The tetracyclines have the additional advantage of inhibiting collagenases. This property may facilitate repair and new attachment formation. Systemic metronidazole appears to be useful as an adjunct to conventional periodontal therapy. The combination of metronidazole 250 mg and amoxycillin 375 mg has been shown to be effective in the treatment of refractory periodontitis, including cases which are resistant to tetracycline. Clindamycin has also been used in the management of refractory periodontitis, but the unwanted effects of this drug must limit its systemic use for this purpose.

Tetracyclines in the management of periodontal diseases. A review

Periodontal diseases essentially comprise a group of oral infections whose primary aetiological factor is dental plaque. Removal of the cause (and its effects) is the primary aim of both non-surgical and surgical treatment regimens, although the infective nature of the diseases has led to the widespread use of antimicrobials as an adjunct to mechanical debridement. The tetracyclines are primarily bacteriostatic agents that are effective against many Gram-negative species including putative periodontopathogens such as Actinobacillus actinomycetemcomitans (A.a.). The proven efficacy of this group of drugs in the management of periodontal diseases may be related not only to their antibacterial actions, but to a number of additional properties that have been recently identified. These include collagenase inhibition, anti-inflammatory actions, inhibition of bone resorption and their ability to promote the attachment of fibroblasts to root surfaces. Consequently, tetracyclines have also been used as an adjunct to bone grafting in periodontal defects, and as agents for 'conditioning' root surfaces to enhance the regeneration of periodontal tissues. When tetracyclines are taken orally, consideration must be given both to the potential unwanted effects and to interactions with other drugs that are taken concurrently. Such problems are minimised however, when the drugs are incorporated into controlled, slow-release formulations which are currently being researched and marketed for intra-oral use.

Inhibition of epithelial cell matrix metalloproteinases by tetracyclines

The effects of tetracyclines on periodontal epithelial cells were investigated by culturing cells from porcine rests of Malassez in the presence of oxytetracycline, doxycycline or one of two analogues of tetracycline bearing no antimicrobial activity. Matrix metalloproteinase activity produced by the epithelial cells was assayed by quantitation of radioactive gelatin degradation and by gelatin enzymography. The results show that all tested tetracyclines exerted a direct dose-dependent inhibitory effect on epithelial cell gelatinases. Furthermore, epithelial cells cultured with doxycycline, oxytetracycline and de-dimethylaminotetracycline in concentrations ranging from 1 to 50 micrograms/ml showed a marked reduction in secreted gelatinase activity when grown in alpha minimum essential medium in the absence of fetal calf serum. Viability of cells following this treatment, measured as lactate dehydrogenase activity released to the cell media, was not affected by the presence of any of these drugs at the concentrations used. Scanning electron microscopy revealed striking morphologic changes of the cells following treatment with tetracyclines in the absence of serum which include rounding, decreased intracellular contacts and increased intercellular spaces. No such effects were seen in cells cultured in the presence of serum. These results provide evidence that periodontal epithelial cells produce matrix metalloproteinases whose activities are inhibited by tetracyclines and their non-antimicrobial analogues at concentrations present in gingival crevicular fluid following tetracycline therapy. When used as adjuncts in periodontal therapy, tetracyclines may therefore inhibit epithelial cell mediated degradation of basement membrane and subepithelial connective tissue.

Prevention of transmission of resistant bacteria between periodontal sites during subgingival application of antibiotics

This study was designed to investigate whether antibiotic resistant micro-organisms are able to contaminate and survive on syringe tips used for subgingival deposition of antibiotics, and to test simple and effective means of disinfecting the syringe tip between applications. In the first part of the study, syringe tips used for application of Minocycline subgingival formula in 20 adult periodontitis patients were cultured for bacteria resistant to this drug before and after disinfecting them with ethanol. The results showed that 80% of the unwashed syringes were culture positive for minocycline resistant bacteria, whereas only 1 ethanol washed syringe tip was contaminated. In part II of the study, after dispensing minocycline periodontal formula in 20 patients, 10 of the syringe tips were washed with ethanol while 10 were left untreated. All syringes were stored in a refrigerator for 8 days, whereafter the tips were sampled for resistant bacteria. 20% of the unwashed tips were contaminated after 8 days incubation at 4 degrees C. None of the ethanol washed syringe tips were culture positive. We conclude that syringe tips may be contaminated with antibiotic resistant bacteria after dispensing the antibiotic in periodontal pockets. The transmission of these bacteria to other periodontal sites may be avoided by disinfecting the syringe tip with ethanol between applications. We have also shown that antibiotic resistant bacteria may survive on the syringe tip following 8 days storage in a refrigerator, suggesting that syringes used for subgingival deposition of an antibiotic should not be stored for reuse.

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.

Intrapocket chemotherapy in adult periodontitis using a new controlled-release insert containing ofloxacin (PT-01)

PT-01 is a newly developed water-soluble controlled-release insert containing ofloxacin (OFLX) as an antibacterial agent. The effect of PT-01 was evaluated by split-mouth application after oral hygiene instruction. No mechanical debridement was carried out during the experiment. PT-01 was applied once a week for 4 weeks in the periodontal pockets of 46 patients with adult periodontitis. The control insert without any antibacterial agent was applied in a selected pocket in a different quadrant for each patient. Clinical findings plaque index, PI; gingival index, GI; bleeding on probing, BOP; pus discharge, pus; and probing depth, PD at both PT-01 and control sites were measured at every visit for 4 weeks. Clinical findings were improved at both PT-01 and control sites, but the improvements were much more significant at PT-01 sites, in particular BOP and PD, than at control sites. PI was also significantly reduced at PT-01 sites. These results suggest that weekly application of PT-01 in the periodontal pocket has a significant effect on the resolution of periodontal inflammation and has an inhibitory effect on supragingival plaque deposition.

Topical chemotherapy in human periodontitis using a new controlled-release insert containing ofloxacin. I. Microbiological observation

The recognition that destructive periodontal diseases may be caused by specific microorganisms in periodontal pockets has led to an increased interest in and usage of antimicrobial agents in periodontal therapy. Recently, a new controlled-release insert containing ofloxacin, a synthetic antibiotic, has been developed. In this study, the controlled-release insert (PT-01) was microbiologically evaluated in combination with or without subgingival mechanical debridement. PT-01 was applied in the periodontal pockets of 27 patients with chronic periodontitis. Three sites with a deep probing pocket depth (greater than or equal to 5 mm) were randomly selected in different quadrants of each patient, and were assigned into three groups, i.e., PT-01 applied (T), placebo applied (P) and control sites (C). Periodontal treatments consisted of supragingival scaling with oral hygiene instruction for the first 2 weeks followed by root planing and subgingival scaling PT-01 was applied weekly on day 0 to 35, and the subgingival plaque samples from each site were collected on d 0, 14, 21 and 42. The dynamics of the subgingival microflora was investigated by dark field microscopy and by anaerobic and aerobic cultivation. In the supragingival scaling period, significant reduction in percentages of spirochetes and motile rods and significant increase of the percentage of coccoid cells were observed only at T sites. In addition, the total viable counts of bacteria, black-pigmented Bacteroides and Fusobacterium species were significantly reduced at T sites. After mechanical subgingival debridement, significant shifts in the proportion and reduction of the viable counts in the subgingival microflora were found at all sites.(ABSTRACT TRUNCATED AT 250 WORDS)

Low-dose doxycycline therapy: effect on gingival and crevicular fluid collagenase activity in humans

Tetracyclines are now recognized to have non-antimicrobial properties with therapeutic potential--for example, these agents can inhibit pathologic collagenolysis by blocking mammalian collagenases and other matrix-degrading metalloproteinases. In the current study, adult human subjects with moderate chronic periodontitis were administered specially formulated capsules of doxycycline, containing lower-than-usual amounts of this semi-synthetic tetracycline, on a daily basis for 2 weeks prior to a full-thickness flap procedure; control subjects were administered placebo capsules. The gingiva excised during this surgical procedure were extracted, the extracts partially purified and analyzed for collagenase activity using [3H-methyl] collagen as substrate and the techniques of SDS-PAGE/fluorography or liquid scintillation spectrometry. In the absence of any drug pre-treatment, or after a 2-wk regimen of placebo capsules, the gingival extracts exhibited pathologically-excessive mammalian collagenase activity. The 2-wk regimen of low-dose doxycycline capsules reduced this activity by approximately 60-80% (p less than 0.05 and less than 0.01, respectively); in vitro exposure of the gingival extract to doxycycline also inhibited its collagenase activity. Collagenase activity in the crevicular fluid of periodontal pockets of an additional group of subjects was also significantly reduced, as was the severity of inflammation at the same gingival sites. The results suggest that a regimen of low-dose doxycycline capsules may provide a safe (other studies indicate that this regimen may not induce tetracycline resistance in the subgingival plaque) and effective adjunct to instrumentation therapy in the management of pathologic collagenolysis in the periodontal patient. However, further studies are necessary to confirm this hypothesis.

Effect of minocycline on subgingival plaque bacteria

The effects of minocycline on subgingival plaque samples from patients with chronic periodontitis were investigated in vitro. Minocycline concentrations as low as 1.0 microgram/ml inhibited 95.7% of the cultivable bacteria in the samples but 256 micrograms/ml was necessary to inhibit all of the cultivable bacteria in the samples. Although up to 99.9% of bacteria in the plaque samples were killed by a 6 h exposure to 8.0 micrograms/ml of minocycline, large numbers of viable bacteria remained. These results imply that adequate reductions in the numbers of viable subgingival plaque bacteria are unlikely to occur after exposure to minocycline at concentrations attainable in gingival crevicular fluid after systemic administration.

Antibiotics in periodontal therapy: advantages and disadvantages

Antibiotic treatment of periodontitis aims at eradicating or controlling specific pathogens. Prime candidates for antibiotic therapy are patients with recently diagnosed active periodontitis or a history of recurrent disease who fail to stabilize following mechanical/surgical therapy. Since a variety of microbes with differing antimicrobial susceptibility profiles may cause periodontitis, selection of antimicrobial agents should be based on proper microbial diagnosis and sensitivity testing, as well as consideration of the patient's medical status. The risk of treating chemotherapeutically solely on the basis of clinical features, radiographic findings or a limited microbiological analysis, is failure to control the pathogens or overgrowth of new pathogens. A review of published papers reveals that appropriate systemic antibiotic therapy may enhance healing in patients with recent or high risk of periodontal breakdown. Systemic antibiotic therapy seems more predictable than topical administration in eradicating periodontal pathogens from deep periodontal pockets. Several promising antimicrobial agents for periodontitis treatment need testing in placebo-controlled, double-blind, randomized clinical trials.

Rationale for the use of antimicrobial agents in periodontal disease

The traditional approach to treating dental decay and periodontal disease has often focused on caries, neglecting periodontal infection. The past 15 years have seen significant advances in the treatment of periodontal disease with antimicrobial therapy, both with and without more traditional debridement or surgery. This article presents an overview of the use of antimicrobials, including an examination of treatment philosophies and the diagnosis of periodontal infection.

Microbiology in diagnosis and treatment of severe periodontitis. A report of four cases

The purpose of this report is to illustrate the use of microbiology in the diagnosis and treatment in four cases of severe adult periodontitis. All four patients were subgingivally infected with Actinobacillus actinomycetemcomitans which was the basis for an adjunct minocycline therapy. Scaling and root planing plus minocycline were not able to establish a clinically stable periodontal condition. A. actinomycetemcomitans was not eliminated from the pockets in any of the patients. Good clinical and microbiological results were obtained after continuous conventional treatment with an adjunct therapy of metronidazole plus amoxycillin. With a 7 day course of this antibiotic therapy, the pockets of all four patients became free of A. actinomycetemcomitans and were still negative on repeated sampling on recall visits. Microbiological monitoring of severe periodontitis in adults seems to be a valuable adjunct to clinical examination. Furthermore, effective antibiotic therapy in A. actinomycetemcomitans-associated periodontitis appears of paramount importance in obtaining a stable periodontal situation.

Bacteriostatic effect of tetracycline in a temporary cement

Temporary crowns with subgingival margins can result in gingival inflammation. This inflammation is the result of plaque accumulating at the restoration-tooth interface and a change in the nature of that plaque to one associated with periodontitis. It was postulated that tetracycline incorporated in a slightly soluble cement would be released in the sulcus and decrease the amount, and improve the quality, of the subgingival microflora. The unknown was whether tetracycline is inactivated by any of the components of the temporary cement Temp Bond. To determine this concern, disks of Temp Bond cement with and without varying concentrations of tetracycline were anaerobically incubated in cultures of Bacteroides gingivalis. Results showed that tetracycline incorporated in Temp Bond at 10% by weight is highly bacteriostatic while retaining typical working properties of the cement.

Effect of modified Widman flap surgery and systemic tetracycline on the subgingival microbiota of periodontal lesions

33 subjects with evidence of active destructive periodontal disease were treated by modified Widman flap surgery and systemic tetracycline (1 g/day for 21 days). Subgingival plaque samples were taken from 41 sites in 12 of these subjects before and 6 months after therapy for predominant cultivable microbiota studies. Mean pocket depth and attachment levels in the 41 sampled sites were 7.1 +/- 2.9 mm and 7.7 +/- 3.2 mm prior to therapy and 4.8 +/- 2.3 mm and 6.2 +/- 3.4 mm after therapy. B. melaninogenicus and V. parvula were more frequently detected in samples taken after therapy, while S. intermedius, S. morbillorum, S. uberis and W. recta were less frequently detected after therapy. A. actinomycetemcomitans were detected in 7 sites pretherapy and 1 site post therapy. The frequency of detection of B. gingivalis and B. intermedius was virtually unchanged. The mean levels of the Actinomyces sp., A. actinomycetemcomitans, B. gingivalis, B. intermedius, S. morbillorum, S. uberis and W. recta were decreased after therapy, while the mean levels of B. melaninogenicus, S. mitis, S. sanguis II and V. parvula were increased after therapy. V. parvula showed the greatest increase to 8.2% of the microbiota. In the second phase of the study, subgingival plaque samples from 94 sites in the 33 treated subjects were analyzed by predominant cultivable techniques. As a result of therapy, 24 sites exhibited attachment loss greater than 2 mm, 23 sites exhibited "gain" greater than 2 mm and the remaining 47 sites were considered to be unchanging.(ABSTRACT TRUNCATED AT 250 WORDS)

Antimicrobial agents in the prevention and treatment of periodontal diseases

It has been estimated that there are more than 400 diseases affecting the oral cavity. In terms of prevalence, however, the major public health problems are caries and periodontal disease. Although these two destructive entities are completely different in many respects, they share a common denominator: the initial lesions are brought about by an aggregate of bacteria known as plaque. This article discusses chemical control of plaque in the treatment of gingivitis and antimicrobial control of subgingival plaque in the treatment of periodontitis. The authors address the use of antibiotics in the treatment of localized juvenile periodontitis, the ideal properties of antiplaque agents, and adjunctive subgingival application of antimicrobial agents.

Is antibiotic therapy justified in the treatment of human chronic inflammatory periodontal disease?

New insight into the possible involvement of specific bacteria in the etiology of periodontal disease has stimulated interest in antibiotic therapy. However, current knowledge does not allow the designation of one or more pathogens in periodontal diseases. Some bacteria are considered suspected periodontal pathogens due to their predominance in the pocket and their potential pathogenicity, yet they all appear to be indigenous bacteria. For this reason, one can question the rationale for the use of antibiotics in the treatment of periodontal disease since the theoretical basis for their application seems small. Several reports of clinical trials in which antibiotics were administered as an adjunct to scaling and rootplaning in adult periodontitis conclude with encouraging statements concerning bacterial inhibition and the cure of inflammatory periodontal disease. However, the data are conflicting and mostly negative. Antibiotic treatment in combination with scaling and rootplaning in juvenile periodontitis and refractory adult periodontitis has shown some benefit, but the clinical trials were not sufficiently controlled to permit conclusions. So far, antibiotics have been applied as a last resort in order to supplement the non-specific approach of mechanical root debridement, but it can be doubted whether this approach offers any benefit in the long run.