Evaluation of periodontal treatments using controlled-release tetracycline fibers: maintenance response

Supra and subgingival application of antiseptics or antibiotics during periodontal therapy

Periodontal diseases (gingivitis and periodontitis) are characterized by inflammatory processes which arise as a result of disruption of the balance in the oral ecosystem. According to the current S3 level clinical practice guidelines, therapy of patients with periodontitis involves a stepwise approach that includes the control of the patient's risk factors and the debridement of supra and subgingival biofilm. This debridement can be performed with or without the use of some adjuvant therapies, including physical or chemical agents, host modulating agents, subgingivally locally delivered antimicrobials, or systemic antimicrobials. Therefore, the main aim of this article is to review in a narrative manner the existing literature regarding the adjuvant application of local agents, either subgingivally delivered antibiotics and antiseptics or supragingivally applied rinses and dentifrices, during the different steps in periodontal therapy performed in Europe.

Drug-Loaded Chitosan Scaffolds for Periodontal Tissue Regeneration

Chitosan is a natural anionic polysaccharide with a changeable architecture and an abundance of functional groups; in addition, it can be converted into various shapes and sizes, making it appropriate for a variety of applications. This article examined and summarized current developments in chitosan-based materials, with a focus on the modification of chitosan, and presented an abundance of information about the fabrication and use of chitosan-derived products in periodontal regeneration. Numerous preparation and modification techniques for enhancing chitosan performance, as well as the uses of chitosan and its metabolites, were reviewed critically and discussed in depth in this study. Chitosan-based products may be formed into different shapes and sizes, considering fibers, nanostructures, gels, membranes, and hydrogels. Various drug-loaded chitosan devices were discussed regarding periodontal regeneration.

Potential of chitosan-based carrier for periodontal drug delivery

Periodontal diseases are chronic infectious diseases and are a major oral health burden. With the progress in the understanding of etiology, epidemiology and pathogenesis of periodontal diseases coupled with the understanding of the polymicrobial synergy in the dysbiotic oral microbial flora, several new therapeutic targets have been identified. The strategies to curb bacterial growth and production of factors that gradually destroy the tissue surrounding and supporting the teeth have been the cornerstone for inhibiting periodontitis. Systemic administration of antibiotics for the treatment of periodontitis have shown several drawbacks including: inadequate antibiotic concentration at the site of the periodontal pocket, a rapid decline of the plasma antibiotic concentration to sub-therapeutic levels, the development of microbial resistance due to sub-therapeutic drug levels and peak-plasma antibiotic concentrations which may be associated with various side effects. These obvious disadvantages have evoked an interest in the development of localized drug delivery systems that can provide an effective concentration of antibiotic at the periodontal site for the duration of the treatment with minimal side effects. A targeted sustained release device which could be inserted in the periodontal pocket and prolong the therapeutic levels at the site of action at a much lower dose is the need of the hour. Chitosan, a deacetylated derivative of chitin has attracted considerable attention owing to its special properties including antimicrobial efficacy, biodegradability, biocompatibility and non-toxicity. It also has the propensity to act as hydrating agent and display tissue healing and osteoinducting effect. The aim of this review is to shine a spotlight on the chitosan based devices developed for drug delivery application in the effective treatment of various periodontal disorders. The chitosan based carriers like fibers, films, sponge, microparticles, nanoparticles, gels that have been designed for sustained release of drug into the periodontal pocket are highlighted.

The anti-inflammatory effect of locally delivered nano-doxycycline gel in therapy of chronic periodontitis

BACKGROUND AND OBJECTIVE

To date, various drugs as host modulating agents had been suggested as adjunctive treatment modality in the therapy of chronic periodontal disease. In this study, the anti-inflammatory effect of subgingivally delivered nanostructured doxycycline gel (nDOX) was evaluated and compared to conventional doxycycline gel (DOX) used as adjunct to scaling and root planning (SRP) in the treatment of moderate chronic periodontitis to reduce probing pocket depth.

MATERIAL AND METHODS

Nanostructured doxycycline gel (nDOX) was prepared using spray-drying technique with chitosan (CH) as a matrix polymer, followed by dispersion in polyvinyl alcohol (PVA). The deepest periodontal pocket in 45 patients suffering from moderate chronic periodontitis was selected. The patients were divided into three groups following scaling and root planning (SRP); group I: SRP + nDOX, group II: SRP + DOX and group III: SRP + placeboCH. Plaque Index (PI), Gingival Index (GI), pocket depth (PD) and clinical attachment level(CAL), as well as ginigival crevicular fluid levels of (GCF) IL-6 and TNF-α were assessed at baseline, 1 and 3 months following local drug application.

RESULTS

Group I showed significant reduction in probing depth and attachment gain compared with group II and III at one and three months period. The inflammatory mediators levels were significantly reduced in all treatment groups at one-month period. Except for group I, the reduced values were observed at three-month period.

CONCLUSION

The results suggest that treatment with nDOX gel as an adjunct to SRP had anti-inflammatory effect by improving both clinical parameters and inflammatory markers up to three months period.

Silicon Nitride Bioceramics Induce Chemically Driven Lysis in Porphyromonas gingivalis

Organisms of Gram-negative phylum bacteroidetes, Porphyromonas gingivalis, underwent lysis on polished surfaces of silicon nitride (Si3N4) bioceramics. The antibacterial activity of Si3N4 was mainly the result of chemically driven principles. The lytic activity, although not osmotic in nature, was related to the peculiar pH-dependent surface chemistry of Si3N4. A buffering effect via the formation of ammonium ions (NH4(+)) (and their modifications) was experimentally observed by pH microscopy. Lysis was confirmed by conventional fluorescence spectroscopy, and the bacteria's metabolism was traced with the aid of in situ Raman microprobe spectroscopy. This latter technique revealed the formation of peroxynitrite within the bacterium itself. Degradation of the bacteria's nucleic acid, drastic reduction in phenilalanine, and reduction of lipid concentration were observed due to short-term exposure (6 days) to Si3N4. Altering the surface chemistry of Si3N4 by either chemical etching or thermal oxidation influenced peroxynitrite formation and affected bacteria metabolism in different ways. Exploiting the peculiar surface chemistry of Si3N4 bioceramics could be helpful in counteracting Porphyromonas gingivalis in an alkaline pH environment.

Tetracycline-Containing MCM-41 Mesoporous Silica Nanoparticles for the Treatment of Escherichia coli

Tetracycline (TC) is a well-known broad spectrum antibiotic, which is effective against many Gram positive and Gram negative bacteria. Controlled release nanoparticle formulations of TC have been reported, and could be beneficial for application in the treatment of periodontitis and dental bone infections. Furthermore, TC-controlled transcriptional regulation systems (Tet-on and Tet-off) are useful for controlling transgene expression in vitro and in vivo for biomedical research purposes; controlled TC release systems could be useful here, as well. Mesoporous silica nanomaterials (MSNs) are widely studied for drug delivery applications; Mobile crystalline material 41 (MCM-41), a type of MSN, has a mesoporous structure with pores forming channels in a hexagonal fashion. We prepared 41 ± 4 and 406 ± 55 nm MCM-41 mesoporous silica nanoparticles with loaded TC for controlled drug release; TC content in the TC-MCM-41 nanoparticles was 18.7% and 17.7% w/w, respectively. Release of TC from TC-MCM-41 nanoparticles was then measured in phosphate-buffered saline (PBS), pH 7.2, at 37 °C over a period of 5 h. Most antibiotic was released from both over this observation period; however, the majority of TC was released over the first hour. Efficacy of the TC-MCM-41 nanoparticles was then shown to be superior to free TC against Escherichia coli (E. coli) in culture over a 24 h period, while blank nanoparticles had no effect.

Evaluation of efficacy of tetracycline fibers in conjunction with scaling and root planing in patients with chronic periodontitis

AIM

The objective of this study was to compare the efficacy of scaling and root planing (SRP) alone versus tetracycline fiber therapy used adjunctively with SRP in the treatment of chronic periodontitis sites in maintenance patients.

MATERIALS AND METHODS

A total of 30 patients with a diagnosis of chronic periodontitis (60 localized chronic periodontitis sites) in the age group of 35 to 55 were selected. None of these patients had received any surgical or non-surgical periodontal therapy and had sites of periodontal pockets measuring 4-7 mm clinically and demonstrated radiographic evidence of moderate bone loss. Two non-adjacent sites in separate quadrants were selected in each patient for monitoring based on criteria that the sites had localized chronic periodontitis. Plaque index (PI) (sillness and loe) and Gingival-bleeding index (GI) (loe and sillness) were measured at baseline and 15(th), 30(th), 60(th), and 90(th)day. Clinical pocket depth (PD) and microbial analysis (MA) were analyzed at baseline and 90(th) day.

RESULTS

At 0 and 3 months adjunctive tetracycline fiber therapy was significantly better in reducing PI, GBI, (P<0.001) than S and RP alone. In comparison, the reduction in the PD was non-significant at 0 and 3 months (P<0.001). The microbial analysis showed significant reduction in Porphyromonas gingivalis and Prevotella intermedia though there was no significant reduction in the Actinobacillus actinomycetemcomitans.

CONCLUSION

Overall, these results indicate that fiber therapy significantly enhanced the effectiveness of SRP in the management of chronic periodontitis.

Effects of a single topical doxycycline administration adjunctive to mechanical debridement in patients with persistent/recurrent periodontitis but acceptable oral hygiene during supportive periodontal therapy

OBJECTIVES

To evaluate the efficacy of a slow release doxycycline gel (SRD) adjunctively administered to non-surgical therapy in subjects with recurrent or persistent periodontitis but acceptable oral hygiene during supportive periodontal care.

MATERIAL & METHODS

In this single blind, parallel group, multicentre study, 202 of 203 recruited periodontal maintenance subjects with recurrent or persistent periodontitis were randomly assigned to subgingival ultrasonic/sonic instrumentation (USI) with (test) or without (control) subsequent administration of SRD in all residual periodontal pockets ≥4 mm. Intergroup differences in probing depth, BOP reductions, treatment time, probing attachment levels were evaluated at 3, 6 and 12 months. The primary outcome was the inter-group difference in absolute change of probing pocket depth (PPD) 3, 6 and 12 months after intervention.

RESULTS

At baseline, the two groups were comparable. At 3 months, the test group showed a significantly higher decrease in mean probing depth than the control group at 3 months (mean difference = 0.11 mm, 95% CI 0.03-0.19 mm, p = 0.003). Administration of SRD resulted in significantly greater odds of transition of bleeding pockets ≥5 mm to a category of non bleeding sites with PPD ≤4 mm at 3 and 6 months (O.R. = 1.4, 95% CI 1.2-1.8 at 3 months). At 6 months, SRD benefit was observed only in the deeper pockets. 7.5% of subjects (no significant difference between test and control) showed disease progression (attachment loss ≥2 mm) and were exited from the study. No difference in the incidence of adverse events was observed between groups.

CONCLUSION

The trial results show that topically administered SRD may provide short-term benefit in controlling inflammation and deep pockets in treated periodontal patients participating in a secondary prevention programme and able to maintain a satisfactory level of oral hygiene.

The Application of Microencapsulation Techniques in the Treatment of Endodontic and Periodontal Diseases

In the treatment of intracanal and periodontal infections, the local application of antibiotics and other therapeutic agents in the root canal or in periodontal pockets may be a promising approach to achieve sustained drug release, high antimicrobial activity and low systemic side effects. Microparticles made from biodegradable polymers have been reported to be an effective means of delivering antibacterial drugs in endodontic and periodontal therapy. The aim of this review article is to assess recent therapeutic strategies in which biocompatible microparticles are used for effective management of periodontal and endodontic diseases. In vitro and in vivo studies that have investigated the biocompatibility or efficacy of certain microparticle formulations and devices are presented. Future directions in the application of microencapsulation techniques in endodontic and periodontal therapies are discussed.

Recent approaches for the treatment of periodontitis

Periodontal disease is a localised inflammatory response caused by the infection of a periodontal pocket arising from the accumulation of subgingival plaque. Periodontal disease has been considered as a possible risk factor for other systemic diseases such as cardiovascular diseases and pre-term low birth weight infants. Advances in understanding the aetiology, epidemiology and microbiology of periodontal pocket flora have revolutionised the therapeutic strategies for the management of periodontal disease progression. This review summarises the recent developments in the field of intra-pocket drug delivery systems and identifies areas where further research may lead to a clinically effective intra-pocket delivery system.

The effect of adjunctive subantimicrobial dose doxycycline therapy on GCF EMMPRIN levels in chronic periodontitis

BACKGROUND

The aim of the present randomized, double-masked, placebo-controlled, parallel-arm study was to examine the effectiveness of a 3-month regimen of subantimicrobial dose doxycycline (SDD) in combination with scaling and root planing compared to scaling and root planing alone on levels of gingival crevicular fluid (GCF) extracellular matrix metalloproteinase inducer (EMMPRIN) in patients with chronic periodontitis.

METHODS

GCF samples were collected, and clinical parameters, including probing depth (PD), clinical attachment level, gingival index (GI), and plaque index, were recorded. Thirty chronic periodontitis subjects were randomized to receive SDD or placebo. The SDD group received SDD (20 mg, twice a day) for 3 months plus scaling and root planing, whereas the placebo group took placebo capsules twice a day for 3 months and received scaling and root planing. The subjects were reevaluated at 3 and 6 months. At each visit, all clinical parameters were measured and GCF was sampled. GCF EMMPRIN levels were determined by Western immunoblotting assay. Intragroup comparisons were tested by the Friedman test followed by the Wilcoxon signed-rank test to analyze the significance of changes over time. The Mann-Whitney test was used to determine differences between the SDD and placebo groups.

RESULTS

Significant improvements were observed in all clinical parameters in the SDD group over the 6-month study period (P <0.025). The SDD group showed a significantly greater reduction in mean PD scores at 6 months and in mean GI scores at 3 and 6 months than the placebo group (P <0.05). From baseline to 6 months, the GCF EMMPRIN levels were reduced significantly in the SDD group (P <0.025). The GCF EMMPRIN level in the SDD group was significantly lower than that of the placebo group at 3 and 6 months (P <0.05).

CONCLUSIONS

SDD therapy in combination with scaling and root planing reduced GCF EMMPRIN levels and improved clinical periodontal parameters in subjects with chronic periodontitis. The ability of SDD to downregulate, in vivo, the GCF levels of EMMPRIN, a unique upregulator of matrix metalloproteinase expression, is one of its beneficial host-modulatory properties. These results expand the usefulness of SDD therapy as an adjunct to scaling and root planing in the long-term management of periodontal disease.

Microbiologic changes following administration of locally delivered doxycycline in smokers: a 15-month follow-up

BACKGROUND

Additional clinical benefits have been reported with the use of locally delivered antimicrobials in the treatment of smokers; however, long-term changes in the subgingival microbiota following the use of these drugs in smokers have not been documented. The aim of this study was to evaluate long-term microbiologic changes following locally delivered doxycycline in the treatment of smokers.

METHODS

Sixteen smokers with chronic periodontitis presenting a minimum of four pockets (probing depth>or=5 mm) were selected. Patients were assigned randomly to receive scaling and root planing (SRP) or SRP and local doxycycline (SRP-D). Patients were treated at baseline and 12 months. Subgingival plaque samples were collected at baseline; 3, 6, and 12 months; and 45 and 90 days following retreatment. Polymerase chain reaction and DNA-DNA hybridization analyses were performed to detect the presence of selected periodontal pathogens.

RESULTS

The reduction in the number of sites positive for Porphyromonas gingivalis and Tannerella forsythia (previously T. forsythensis) was statistically significant for SRP-D at 3 months (68% and 41.3%, respectively) and for SRP at 6 months (75% and 52%, respectively) following treatment. The SRP group showed a greater frequency of P. gingivalis than the SRP-D group at 3 months (58% and 25%, respectively). There also was a greater reduction in the frequency of P. gingivalis at 3 months following retreatment with SRP-D compared to SRP (47% and 8%, respectively).

CONCLUSION

In smokers, adjunctive local doxycycline resulted in a greater reduction in the frequency of P. gingivalis following initial and supportive therapy compared to conventional treatment.

Local Drug Delivery in the Treatment of Periodontal Diseases: Assessing the Clinical Significance of the Results

BACKGROUND

Local drug delivery can be used in the management of periodontal patients. However, statistically significant responses to therapy recorded in clinical trials may not be clinically significant.

METHODS

Controlled clinical trials were selected that assessed the capability of local drug delivery to improve periodontal health.

RESULTS

Several local drug delivery systems employed as monotherapies improved periodontal health and provided results that were not statistically significantly different than attained with scaling and root planing (SRP) alone. In contrast, many local drug delivery devices when used as adjuncts to SRP provided a statistically significant enhancement of parameters commonly used to monitor periodontal status. However, mean improvements with respect to probing depth reduction or gain of clinical attachment were often limited to tenths of millimeters. Several devices also achieved specific criteria that can be used to identify clinically significant findings (e.g., number of sites with probing depth reduction >or=2 mm). However, there are conflicting data with respect to the ability of local drug delivery to enhance results of SRP at deep probing sites, and there is limited information relative to its capability to inhibit disease progression or enhance osseous repair in infrabony defects.

CONCLUSION

The decision to use local drug delivery during active treatment or maintenance should be based upon clinical findings, responses to therapy recorded in the literature, desired clinical outcomes, and the patient's dental and medical history.

Tetracycline Fibers as an Adjunct in the Treatment of Nifedipine-Induced Gingival Enlargement

BACKGROUND

The hypothesis that nifedipine-induced gingival enlargement in periodontitis patients can be treated with the adjunctive use of tetracycline (TCN) fibers was tested in this study.

METHODS

Ten patients (mean age 66 +/- 4 years) with chronic periodontitis combined with nifedipine-induced gingival enlargement participated. Full mouth recordings of clinical parameters (probing depth, clinical attachment level, bleeding on probing, presence or absence of plaque) were assessed at baseline and gingival enlargement was estimated from casts. Participants were instructed in proper oral hygiene and received supragingival scaling before being reassessed 1 month later. They subsequently received full-mouth scaling and root planing followed by the immediate placement of TCN fibers in all pockets >5 mm. Clinical parameters were reassessed at 3, 6, and 12 months after completion of treatment.

RESULTS

TCN fiber placement was well tolerated by patients. All clinical parameters recorded displayed significant improvements after treatment, and they were preserved for the 12-month experimental period. A significant reduction of the percentage of pockets >5 mm was noticed after treatment. The reduction of enlargement was still observed at 12 months despite patients not achieving optimal oral hygiene.

CONCLUSION

Placement of tetracycline fibers as an adjunct to mechanical treatment is an option for the non-invasive therapy of nifedipine-induced gingival enlargement in periodontitis patients whose general medical condition and concomitant ailments do not favor a surgical approach.

Microbiological Changes With the Use of Locally Delivered Doxycycline in the Periodontal Treatment of Smokers

BACKGROUND

The aim of this study was to evaluate the effect of the association of locally delivered doxycycline 10% and scaling and root planing in the subgingival plaque of smokers.

METHODS

Sixteen smokers with chronic periodontitis and a minimum of four pockets (> or = 5 mm) on anterior teeth that bled on probing were selected. Patients were randomly assigned to one of the following groups: scaling and root planing (SRP) or scaling and root planing followed by local application of doxycycline (SRP-D). Subgingival plaque samples were collected from initially moderate (5 to 6 mm) and deep (> or = 7 mm) pockets at baseline and 3 months. Polymerase chain reaction (PCR) analysis was used to detect the frequency of Actinobacillus actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), and Tannerella forsythensis (Tf).

RESULTS

No statistically significant difference was found in the reduction of Aa in either the SRP-D or SRP group (P > 0.05). The reduction in Tf, Pg, and Tf + Pg was statistically significant for SRP-D only (P = 0.016, 0.027, and 0.027, respectively). The proportion of sites free of Tf at 3 months was 53% for SRP-D and 9% for SRP (P = 0.02). For Pg, this proportion was 82% and 40%, respectively (P = 0.05).

CONCLUSION

The use of locally delivered doxycycline may promote the elimination of T. forsythensis and P. gingivalis in a greater proportion of sites compared to conventional scaling and root planing in smokers.

Effectiveness of Adjunctive Low-Dose Doxycycline Therapy on Clinical Parameters and Gingival Crevicular Fluid Laminin-5 γ2 Chain Levels in Chronic Periodontitis

BACKGROUND

Laminin-5 (Ln-5) is involved in the apical migration of epithelial cells during the development of periodontal pockets. Low-dose doxycycline (LDD) can therapeutically modulate the host response with its non-antimicrobial properties. In the present randomized, double-blind, placebo-controlled, parallel arm study, the effectiveness of LDD in combination with non-surgical periodontal therapy on gingival crevicular fluid (GCF) Ln-5 gamma2 chain fragment levels and clinical parameters in patients with chronic periodontitis was examined over a 12-month period.

METHODS

GCF samples were collected and clinical parameters including probing depth (PD), clinical attachment level, gingival index (GI), and plaque index were recorded. Thirty chronic periodontitis patients were randomized either to low-dose doxcycline or placebo groups. LDD group received doxycycline (20 mg, b.i.d.) for 3 months plus scaling and root planing (SRP), while placebo group was given placebo capsules b.i.d. for 3 months plus SRP. The patients were evaluated every 3 months during the 12-month study period. All clinical parameters and GCF sampling were repeated at each visit. GCF Ln-5 gamma2 chain fragment levels were determined by Western immunoblotting using specific antibody and quantitated by computerized image analysis. Friedman test was used for intragroup comparisons followed by Wilcoxon signed rank test to analyze significance of changes over time. The Mann-Whitney test was used to determine differences between both LDD and placebo groups.

RESULTS

Both groups revealed significant improvements in all clinical parameters over the 12-month period (P < 0.0125). LDD group showed a significantly greater reduction in the mean PD scores at 9 and 12 months and in the mean GI scores at all time points than the placebo group (P < 0.05). In the LDD group, GCF Ln-5 gamma2 chain fragment levels were significantly reduced at 3 months (P < 0.0125) and then slightly increased during the rest of the study period. In the placebo group, GCF 45 and 70 kDa Ln-5 gamma2 chain fragments tended to decrease at 3 months compared to baseline, but did not reach significance; these levels continued to increase throughout the remainder of the study period. GCF Ln-5 gamma2 chain fragment levels in LDD group were significantly lower than those of the placebo group during the study period (P < 0.05).

CONCLUSIONS

The present data indicate that LDD therapy in combination with SRP therapy can reduce GCF Ln-5 gamma2 chain fragment levels and improve clinical periodontal parameters in patients with chronic periodontitis. Since matrix metalloproteinases (MMP)-mediated fragmentation of laminin-5 can contribute to pocket formation by stimulating epithelial cell migration, the reduction of Ln-5 gamma2 chain fragment levels could provide a new mechanism by which LDD, adjunctive to SRP, inhibits periodontal disease more effectively than SRP alone. Thus, these results provide extended and additional information about the effectiveness of the LDD therapy as an adjunct to non-surgical periodontal therapy in the long-term management of periodontal disease.

Antibiotic resistance profile of the subgingival microbiota following systemic or local tetracycline therapy

BACKGROUND

Tetracyclines have been extensively used as adjunctives to conventional periodontal therapy. Emergence of resistant strains, however, has been reported. This study evaluated longitudinally the tetracycline resistance patterns of the subgingival microbiota of periodontitis subjects treated with systemic or local tetracycline therapy+scaling and root planing (SRP).

METHODS

Thirty chronic periodontitis patients were randomly assigned to three groups: SRP+500 mg of systemic tetracycline twice/day for 14 days; SRP alone and SRP+tetracycline fibers (Actsite) at four selected sites for 10 days. Subgingival plaque samples were obtained from four sites with probing pocket depths (PPD)> or =6 mm in each patient at baseline, 1 week, 3, 6 and 12 months post-therapy. Samples were dispersed and diluted in pre-reduced anaerobically sterilized Ringer's solution, plated on Trypticase Soy Agar (TSA)+5% blood with or without 4 microg/ml of tetracycline and incubated anaerobically for 10 days. The percentage of resistant microorganisms were determined and the isolates identified by DNA probes and the checkerboard method. Significance of differences among and within groups over time was sought using the Kruskal-Wallis and Friedman tests, respectively.

RESULTS

The percentage of resistant microorganisms increased significantly at 1 week in the tetracycline groups, but dropped to baseline levels over time. The SRP+Actsite group presented the lowest proportions of resistant species at 6 and 12 months. No significant changes were observed in the SRP group. The predominant tetracycline-resistant species included Streptococcus spp., Veillonela parvula, Peptostreptococcus micros, Prevotella intermedia, Gemella morbillorum and Actinobacillus actinomycetemcomitans (Aa). A high percentage of sites with resistant Aa, Porphyromonas gingivalis and Tanerella forsythensis was observed in all groups at baseline. However, T. forsythensis was not detected in any group and P. gingivalis was not present in the SRP+Actsite group at 1 year post-therapy. Aa was still frequently detected in all groups after therapy. However, the greatest reduction was observed in the SRP+Actsite group.

CONCLUSION

Local or systemically administered tetracycline results in transitory selection of subgingival species intrinsically resistant to this drug. Although the percentage of sites harboring periodontal pathogens resistant to tetracycline were quite elevated in this population, both therapies were effective in reducing their prevalence over time.

The effect of adjunctive low-dose doxycycline therapy on clinical parameters and gingival crevicular fluid matrix metalloproteinase-8 levels in chronic periodontitis

BACKGROUND

Low-dose doxycycline (LDD) is recognized to have non-antimicrobial properties that can therapeutically modulate the host response. The aim of the present randomized, double-blind, placebo-controlled, parallel-arm study was to examine the effectiveness of LDD in combination with non-surgical periodontal therapy, compared to non-surgical periodontal therapy alone, on gingival crevicular fluid (GCF) matrix metalloproteinase-8 (MMP-8) levels and clinical parameters over a 12-month period in patients with chronic periodontitis.

METHODS

GCF samples were collected, and clinical parameters including probing depth (PD), clinical attachment level, gingival index (GI), and plaque index were recorded. Thirty chronic periodontitis patients were randomized either to a low-dose doxycycline (LDD) or placebo group. The LDD group received low-dose doxycycline (20 mg) b.i.d. for 3 months plus scaling and root planing (SRP), while the placebo group was given placebo capsules b.i.d. for 3 months plus SRP. The patients were evaluated every 3 months during the 12-month study period. At each visit, all clinical measurements and GCF sampling were repeated. GCF MMP-8 levels were determined by a time-resolved immunofluorescence assay. Intragroup comparisons were tested by the Friedman test followed by Wilcoxon signed-rank test to analyze significance of changes over time. The Mann-Whitney test was used to determine differences between the LDD and placebo groups.

RESULTS

Significant improvements were observed in all clinical parameters in both groups over the 12-month period (P < 0.0125). The LDD group showed a significantly greater reduction in mean PD scores at 9 and 12 months and in mean GI scores at all time points than the placebo group (P < 0.05). From baseline to 12 months, GCF MMP-8 levels were significantly reduced in both groups (P < 0.0125). The GCF MMP-8 level in the LDD group was significantly lower than that of the placebo group at 6 months (P < 0.05).

CONCLUSIONS

The present results indicate that low-dose doxycycline therapy in combination with scaling and root planing can reduce GCF MMP-8 levels and improve clinical periodontal parameters in patients with chronic periodontitis. These results provide additional information about the usefulness of low-dose doxycycline therapy as an adjunct to non-surgical periodontal therapy in the long-term management of periodontal disease. The effectiveness and course of low-dose doxycycline therapy can be monitored conveniently by assessing GCF MMP-8 levels.

Local anti-infective therapy: pharmacological agents. A systematic review

BACKGROUND

It is well recognized that periodontal diseases are bacterial in nature. An essential component of therapy is to eliminate or control these pathogens. This has been traditionally accomplished through mechanical means (scaling and root planing [SRP]), which is time-consuming, difficult, and sometimes ineffective. Over the past 20 years, locally delivered, anti-infective pharmacological agents, most recently employing sustained-release vehicles, have been introduced to achieve this goal.

RATIONALE

This systematic review evaluates literature-based evidence in an effort to determine the efficacy of currently available anti-infective agents, with and without concurrent SRP, in controlling chronic periodontitis.

FOCUSED QUESTION

In patients with chronic periodontitis, what is the effect of local controlled-release anti-infective drug therapy with or without SRP compared to SRP alone on changes in clinical, patient-centered, and adverse outcomes?

SEARCH PROTOCOL

MEDLINE, the Cochrane Central Trials Register, and Web of Science were searched. Hand searches were performed of the Journal of Clinical Periodontology, Journal of Periodontology, and Journal of Periodontal Research. Searches were performed for articles published through April 2002. In addition, investigators contacted editors of the above-mentioned journals and companies sponsoring research on these agents for related unpublished data and studies in progress.

SELECTION CRITERIA

INCLUSION CRITERIA

Studies included randomized controlled clinical trials (RCT), and case-controlled and cohort studies at least 3 months long. Therapeutic interventions had to include 1) SRP alone; 2) local anti-infective drug therapy and SRP; or 3) local anti-infective drug therapy alone. Included studies had to report patient-based mean values and measures of variation for probing depth (PD) and/or clinical attachment levels (CAL) for both test and control groups.

EXCLUSION CRITERIA

Studies were excluded if they: 1) included data from a previously published article; 2) included daily rinsing with chlorhexidine (CHX); or 3) had unclear descriptions of randomization procedures, examiner masking, or concomitant therapies.

DATA COLLECTION AND ANALYSIS

For the meta-analysis, PD and CAL were expressed as summary mean effects with 95% confidence intervals (CI) for the effect, and analyzed using a standardized difference between SRP alone and experimental agent groups. The results were assessed with both fixed-effects and random-effects models. Studies were ranked according to the York system.

MAIN RESULTS

1. Thirty-two studies were included (28 RCT, 2 cohort, and 2 case-control), incorporating a total patient population of 3,705 subjects. 2. Essentially all studies reported substantial reductions in gingival inflammation and bleeding indices, which were similar in both control and experimental groups. 3. A meta-analysis completed on 19 studies that included SRP and local sustained-release agents compared with SRP alone indicated significant adjunctive PD reduction or CAL gain for minocycline (MINO) gel, microencapsulated MINO, CHX chip and doxycycline (DOXY) gel during SRP compared to SRP alone. 4. Use of antimicrobial irrigants or anti-infective sustained-release systems as an adjunct to SRP does not result in significant patient-centered adverse events.

REVIEWERS' CONCLUSIONS

1. In some populations, anti-infective agents in a sustained-release vehicle alone can reduce PD and bleeding on probing (BOP) equivalent to that achieved by SRP alone. 2. No evidence was found for an adjunctive effect on reduction of PD and BOP of therapist-delivered CHX irrigation during SRP compared to SRP alone. 3. Additional RCTs are needed which evaluate the effectiveness of these therapies in all forms of periodontitis. 4. The study protocol for future RCTs should include appropriate statistical analyses and complete data sets to facilitate future evidence-based reviews. 5. Alternative surrogate parameters to PD and CAL need to be identified and validated such as microbial, inflammatory, or tissue-destructive markers that could be used in conjunction with clinical parameters to help determine the patient's response to emerging technologies that target the infectious and/or inflammatory aspects of periodontitis. 6. Future Phase IV clinical trials should be designed that evaluate local anti-infective therapies in conjunction with SRP in a manner consistent with current standards of care and evaluate cost-effectiveness. 7. The use of local anti-infective agents in at-risk patient populations and for the treatment of at-risk disease sites needs to be validated in randomized controlled clinical trials. 8. Several local anti-infective agents combined with SRP appear to provide additional benefits in PD reduction and CAL gain compared to SRP alone. The decision to use local anti-infective adjunctive therapy remains a matter of individual clinical judgment, the phase of treatment, and the patient's status and preferences.

Novel mucoadhesive buccal formulation containing metronidazole for the treatment of periodontal disease

Mucoadhesive tablets using different mixture of cellulose and polyacrylic derivatives were prepared in order to obtain new formulations containing metronidazole for periodontal disease treatment. All tablets were characterized by swelling studies, ex vivo and in vivo mucoadhesive time, ex vivo mucoadhesion force, in vitro and in vivo release. The best mucoadhesive performance and the best in vitro drug release profile were achieved by using hydroxyethyl cellulose (HEC) and carbomer 940 2:2 ratio. The chosen tablet, containing 20 mg of metronidazole, performed 12 h drug sustained release with buccal concentrations always higher than its MIC.

Topical and systemic antibiotics in the management of periodontal diseases

Both systemic and topical antibiotics are increasingly used in the management of periodontal infections. Whilst these drugs are used mostly on an empirical basis, some contend that rational use of antibiotics should be the norm due to their wide abuse and consequential global emergence of antibiotic resistance organisms. Here we review the rationale and principles of antimicrobial therapy, treatment goals, drug delivery routes and various antibiotics that are used in the management of periodontal diseases. The pros and cons of systemic and local antibiotic therapy are described together with practical guidelines for their delivery. The available data indicate, in general, that mechanical periodontal treatment alone is adequate to ameliorate or resolve the clinical condition in most cases, but adjunctive antimicrobial agents, delivered either locally or systemically, can enhance the effect of therapy in specific situations. This is particularly true for aggressive (early onset) periodontitis, in patients with generalised systemic disease that may affect host resistance and in case of poor response to conventional mechanical therapy. Locally delivered antibiotics together with mechanical debridement are indicated for non-responding sites of focal infection or in localised recurrent disease. After resolution of the periodontal infection, the patient should be placed on an individually tailored maintenance care programme. Optimal plaque control by the patient is of paramount importance for a favourable clinical and microbiological response to any form of periodontal therapy.

Locally delivered antimicrobials for the treatment of chronic periodontitis

The basic treatment of chronic periodontitis is a mechanical debridement of periodontal pockets by scaling and root planing (S/RP) in combination with efficient plaque control. Locally delivered antiseptics (LDA) have been proposed to practitioners and, while subgingival irrigation of antiseptics is still used in clinical practice, the introduction in our therapy of a slow release and sub-gingival delivery of tetracycline has changed the rationale from a mechanical treatment towards a combined therapy for full mouth/sites disinfection. Various antibiotics, antiseptics and resorbable carriers are now proposed with similar targets to arrest disease progression. In chronic periodontitis, LDA cannot be used routinely in combination with S/RP, because of the limited clinical benefit, even if an increased percentage of deep sites may show an improvement. Prospective multicenter studies considering risk factors for disease progression have to be designed to identify patients who may benefit the most from LDA. For non-responding sites or recurrent pockets, the controversies are limited, because a combined S/RP and LDA may avoid the need for surgery. However, the patient cost/benefit ratio needs to be estimated as well as adverse effects in particular antibiotics.

Periodontal therapy using local delivery of antimicrobial agents

Antimicrobial agents, systemic and/or local, are thought by some to be effective agents for treating periodontal infections. Here the authors determine the costs and benefits of local delivery agents for treating periodontal disease. Applying this cost-benefit analysis to patient care, however, will depend upon a clinician's expertise and a patient's value system.

Effect of polylactide/glycolide (PLGA) membranes loaded with metronidazole on periodontal regeneration following guided tissue regeneration in dogs

BACKGROUND

Bioabsorbable membranes have been successfully used for guided tissue regeneration (GTR) and local delivery systems because they are biocompatible and do not require second surgery for removal. Several studies have demonstrated that metronidazole, when applied topically, produced immediate effects on microbiological and clinical parameters, most notably a reduction in probing depth and loss of attachment. The purpose of this study was to evaluate the regenerative potential of a metronidazole-loaded biodegradable (polylactide/glycolide) (PLGA) GTR membrane in dogs.

METHODS

Six male adult dogs with 36 created osseous defects were enrolled. Bilateral dehiscence type defects in 5 mm diameter were created at buccal aspect of the alveolar bone in maxillary premolar teeth. After full thickness flap elevation, exposed root surfaces were thoroughly planed. In the experimental sites, PLGA membranes with or without metronidazole were fitted and placed over the defects. On the control defects only root planing was performed. Gingival flaps were replaced slightly coronal to the cemento-enamel junction. Animals were sacrificed at 60 days. The histometric analysis was evaluated with the following parameters: defect height (DH), apical extension of junctional epithelium (AEJE), new cementum height (NCH), new bone height (NBH), and new gingival connective tissue height (NCTH).

RESULTS

Postoperative clinical healing was similar in the 3 groups. There were no statistically significant differences between the 2 experimental groups in any parameters. Statistically significant differences were observed for AEJE, NCH, NBH, and NCTH in experimental groups when compared with the controls. Statistically significantly greater NCH, NBH, and NCTH were seen in the experimental groups than the controls and control defects showed longer AEJE than the experimental defects.

CONCLUSIONS

These results suggest that PLGA membranes with and without metronidazole may have a beneficial effect on periodontal regeneration.

Treatment of plaque-induced gingivitis, chronic periodontitis, and other clinical conditions

The inflammatory components of plaque induced gingivitis and chronic periodontitis can be managed effectively for the majority of patients with a plaque control program and non-surgical and/or surgical root debridement coupled with continued periodontal maintenance procedures. Some patients may need additional therapeutic procedures. All of the therapeutic modalities reviewed in this position paper may be utilized by the clinician at various times over the long-term management of the patient's periodontal condition.

The effect of locally delivered controlled-release doxycycline or scaling and root planing on periodontal maintenance patients over 9 months

BACKGROUND

This research report evaluates clinical changes resulting from local delivery of doxycycline hyclate (DH) or traditional scaling and root planing (SRP) in a group of patients undergoing supportive periodontal therapy (SPT).

METHODS

In all, 141 patients received either DH (67) or SRP (74) treatment in sites > or =5 mm on one-half of their dentition at baseline and month 4.

RESULTS

Clinical results were determined at month 9. Baseline mean probing depth recordings were similar between the two groups (DH = 5.9 mm; SRP = 5.9 mm). Mean month 9 results showed similar clinical results for attachment level gain (DH 0.7 mm; SRP 0.8 mm) and probing depth reduction (DH 1.3 mm; SRP 1.1 mm). Percentage of sites showing > or =2 mm attachment level gain at month 9 was 24.7% in the DH group and 21.2% in the SRP group. Thirty-nine percent (39%) of DH sites and 38% of SRP sites showed > or =2 mm probing depth reduction. When treated sides of the dentition were compared to untreated sides, DH showed a difference in disease activity (> or =2 mm attachment loss) from 19.3% (untreated) to 7.2% (treated); and SRP from 14.3% (untreated) to 8.1% (treated).

CONCLUSIONS

Results show that both DH without concomitant mechanical instrumentation and SRP were equally effective as SPT in this patient group over the 9-month study period.

Local delivery of tetracycline: from concept to clinical application

This manuscript reviews the development over the last 20 years of the evidence supporting the clinical application of a controlled delivery device for the treatment of human periodontitis. The device is a monolithic ethylene vinyl-acetate fibre loaded with 25% w/w tetracycline HCI (tetracycline fibre). It releases tetracycline at a steady state rate of 2 microg/cm x h and results in the maintenance of essentially constant, highly-effective concentrations of tetracycline at the site of action. A series of controlled, randomised, single-blind, phase-III clinical trials including a total of 463 patients has indicated that: (1) tetracycline fibres result in significantly better outcomes than the scaling and root planing positive control; (2) combination of tetracycline fibres with subgingival mechanical debridement results in significant improvement over debridement alone. Evidence from these studies has led to approval of this treatment modality by the US Food and Drug Administration and by the European Union Regulatory Bodies. A clinical usage study involving 2711 subjects treated by 68 clinicians in Europe and North America indicated that the magnitude of the observed clinical outcomes is clinically relevant and that adverse events were rarely observed. A variety of clinical investigations aimed at the optimal incorporation of tetracycline fibres in a treatment strategy provide guidance in case selection. Cost of therapy and concerns of unnecessary usage of antibiotics should be considered. It is nonetheless concluded that combination of tetracycline fibres with mechanical debridement represents a documented treatment alternative, the application of which may offer clinical benefits to many patients.

A controlled multicenter study of adjunctive use of tetracycline periodontal fibers in mandibular class II furcations with persistent bleeding

The aim of this randomized single-blind multicenter controlled clinical trial was to clinically evaluate the effectiveness of adjunctive local controlled drug delivery in the control of bleeding on probing in mandibular class II furcations during maintenance care. 127 patients presenting with a class II mandibular furcation with bleeding on probing were included in the study. They had been previously treated for periodontitis and were participating in supportive care programs in periodontal specialty practices. Treatments consisted of scaling and root planing with oral hygiene instructions (control) and scaling and root planing and oral hygiene combined with local controlled drug delivery with tetracycline fibers (test). The following outcomes were evaluated at baseline and 3 and 6 months after therapy at the furcation site: bleeding on controlled force probing (BOP), probing pocket depth (PD) and clinical attachment levels (CAL). Levels of oral hygiene and smoking status were also assessed. Both test and controls resulted in significant improvements of BOP and PD at 3 and 6 months. The test treatment, however, resulted in significantly better improvements: BOP decreased by 52% in the control group and by 70% in the test group at 3 months; at 6 months, however, the difference was no longer significant. The test treatment resulted in a 0.5 mm greater reduction of PD than the control at 3 months, the improvement was highly significant but its duration did not extend until the 6 months evaluation. No differences were observed in terms of changes in CAL. These data indicate that addition of tetracycline fibers to mechanical therapy alone resulted in improved control of periodontal parameters during periodontal maintenance of class II mandibular furcations. Short duration of the effect, however, requires further investigations to optimize conservative treatment of these challenging defects.

Retention, antimicrobial activity, and clinical outcomes following use of a bioerodible tetracycline gel in moderate-to-deep periodontal pockets

This randomized, examiner masked, split mouth study evaluated a new model to test periodontal therapy involving a novel bioerodible copolymer gel containing tetracycline hydrochloride. Responses to the tetracycline gel and untreated control were compared for product tolerance and 3 different measures of effectiveness (drug retention, changes in microbial levels, and clinical status). The test gel was administered by syringe into the periodontal pockets of 18 systemically healthy adult volunteers, each of whom presented with 3 or more sites with 6 mm probing depths. Gingival crevicular fluid samples were used to monitor daily drug levels over 7 days, while clinical responses were assessed at day 30. Overall, the test gel was well-tolerated by all patients. For the 3 effectiveness measures, tetracycline was released throughout the observation period and mean levels exceeded 100 microg/mL over 6 days, statistically significant reductions in selected periodontal pathogens were evident at day 7 but not at day 30, and mean probing depth reductions at test sites were 1.12 mm at 30 days versus 0.36 mm at untreated control sites (P=0.012). The safety profile, longer-term drug retention, antimicrobial activity, and clinical response in this Phase I study suggest that this tetracycline-containing copolymer gel platform may represent a safe and effective bioerodible therapy for periodontitis. The experimental model also shows merit for early phase clinical testing of novel therapeutic agents.

The role of local drug delivery in the management of periodontal diseases: a comprehensive review

This review article evaluates the role of local drug delivery systems in the management of periodontal diseases. The efficacy of several local delivery devices (i.e., tetracycline fibers, metronidazole and minocycline gels, chlorhexidine chips, and doxycycline polymer) which are either commercially available in the United States or abroad, or are currently under consideration for Food and Drug Administration (FDA) approval are discussed. The drug delivery systems are assessed with regard to their functional characteristics, effectiveness as a monotherapy, as compared to scaling and root planing, and ability to enhance conventional therapy. Furthermore, controversies associated with local delivery are addressed (e.g., induction of bacterial resistant strains, the efficacy of systemic versus local drug delivery, and whether local drug delivery should function as an alternative or as an adjunct to conventional treatment).

Subgingival controlled release of antimicrobial agents in the treatment of periodontal disease

Local drug delivery of antimicrobics by sustained release delivery systems can be used to treat periodontal disease. Advantages of these systems may include biodegradation of the system, maintaining high levels of antibiotic in the gingival crevicular fluid (GCF) for a sustained period of time and ease of use with high patient acceptance. This review will identify human in vivo clinical and microbiological studies. Sustained release formulations, application methods, clinical results and microbiological effects are discussed.

Tetracycline fibers plus scaling and root planing versus scaling and root planing alone: similar results after 5 years

This paper presents 5-year data pertaining to a subgroup of patients from a previous investigation who were treated with scaling and root planing plus tetracycline fibers. The parent study demonstrated that 6 months after therapy, scaling and root planing plus tetracycline fiber therapy was significantly better at reducing probing depth and gaining clinical attachment than scaling and root planing alone. However, the long-term data presented here show a regression from the original gains in clinical attachment levels in the fiber group. Ultimately, the use of fibers provided no significant advantage with regards to probing depth reduction or clinical attachment gain. Within the power of this study, which would have required 1.78 mm of change in clinical attachment to show a difference, there was no significant difference between the treatments at 5 years. This study underscores the need for additional long-term evaluation of this mode of therapy.

The effect of SRP on the clinical and microbiological parameters of periodontal diseases

The purpose of the present investigation was to examine the effect of SRP on clinical and microbiological parameters in 57 subjects with adult periodontitis (mean age 47 +/- 11 years). Subjects were monitored clinically and microbiologically prior to and 3, 6 and 9 months after full-mouth SRP under local anaesthesia. Clinical assessments of plaque, redness, suppuration, BOP, pocket depth and attachment level were made at 6 sites per tooth. The means of duplicate attachment level measurements taken at each visit were used to assess change between visits. Clinical data were averaged within each subject and then averaged across subjects for each visit. Subgingival plaque samples were taken from the mesial aspect of each tooth and the presence and levels of 40 subgingival taxa were determined using whole genomic DNA probes and checkerboard DNA-DNA hybridization. The mean levels and % of sites colonized by each species (prevalence) was computed for each subject at each visit. Differences in clinical and microbiological parameters before and after SRP were sought using the Wilcoxon signed ranks test or the Quade test for more than 2 visits. Overall, there was a mean gain in attachment level of 0.11 +/- 0.23 mm (range -0.53 to 0.64 mm) 3 months post-therapy. There was a significant decrease in the % of sites exhibiting gingival redness (68 to 57%) and BOP (58 to 52%) as well as a mean (+/-SEM) pocket depth (3.3 +/- 0.06 to 3.1 +/- 0.05 mm). Sites with pre-therapy pocket depths of < 4 mm showed a non-significant increase in pocket depth and attachment level, 4.6 mm pockets showed a significant decrease in pocket depth and a non-significant gain in attachment post-therapy, while > 6 mm pockets showed a significant decrease in pocket depth and attachment level measurements post-therapy. Significant clinical improvements were seen in subjects who had never smoked or were past smokers but not in current smokers. Mean prevalences and levels of P. gingivalis, T. denticola and B. forsythus were significantly reduced after SRP, while A. viscosus showed a significant increase in mean levels. The mean decrease in prevalence of P. gingivalis was similar at all pocket depth categories, while B. forsythus decreased more at shallow and intermediate pockets and A. viscosus increased most at deep sites. P. gingivalis. B. forsythus and T. denticola were equally prevalent among current, past and never smokers pre-therapy, decreased significantly post-SRP in never and past smokers but increased in current smokers. Clinical improvement post-SRP was accompanied by a modest change in the subgingival microbiota, primarily a reduction in P. gingivalis, B. forsythus and T. denticola, suggesting potential targets for therapy and indicating that radical alterations in the subgingival microbiota may not be necessary or desirable in many patients.

Overview of periodontal clinical trials utilizing anti-infective or host modulating agents

Issues in periodontal trials designed to evaluate anti-infective or host modulating agents for the prevention and treatment of periodontal diseases are reviewed in this paper. Clinical trial designs, prevention versus treatment, disease activity, utility of new measurement technologies, ethical and safety issues, selection of outcome variables, and clinical significance are discussed. In general, randomized parallel arm, double-blinded, controlled clinical trials are most appropriate for testing anti-infective and host modulating agents. New measurement technologies may offer increased measurement resolution and automated data capture; but, depending on their specific application and level of examiner reproducibility, these technologies may or may not result in lowered thresholds for declaring change. Mechanical therapy for common plaque-associated gingivitis and adult periodontitis is effective, has low risk, and is widely accepted as a minimum standard of care. New agents for treatment of these diseases must carry minimal risk and have equal or greater effectiveness than this standard of care. Outcome variables for gingivitis trials should include a visual index of gingival inflammation and a separate or component index of gingival bleeding. Prevention studies of periodontitis require a longer duration than treatment studies. Maintenance of mean clinical attachment level should be a primary outcome measure for all prevention studies of adult periodontitis. Maintenance of alveolar bone support is an essential additional outcome for agents specifically acting on bone. The design and conduct of clinical trials for anti-infective and host modulating agents depend on the specific hypothesis to be tested and the ethical demands of providing safe and effective care for all study volunteers.

Subgingival delivery of therapeutic agents in the treatment of periodontal diseases

This article reviews the current status of controlled local delivery of antibacterial agents in the treatment of periodontitis. The principle of local intrapocket delivery of antibacterial agents and their delivery are discussed. The dosage forms include fibers, film/slabs, and injectable systems, some of which are degradable, while others are not and need to be removed at the termination of the treatment. The antibacterial agents used cover a range of antibiotics as well as antiseptics, and the composition of the delivery systems, their reported use, and the clinical results are summarized. The use of these systems in clinical practice is relatively recent, and therefore their application and integration into the dental office are not yet clearly defined. Clinical applications that have been tested are critically reviewed, and clinical situations in which controlled delivery of antibacterial agents may prove to be clinically useful are suggested for scientific evaluation.

Adjunctive controlled topical application of tetracycline HCl in the treatment of localized persistent or recurrent periodontitis. Effects on clinical parameters and elastase-alpha1-proteinase inhibitor in gingival crevicular fluid

35 patients receiving regular supportive periodontal therapy (SPT) and showing signs of localized persistent or recurrent periodontitis were enrolled in the study. Within 1 week after SPT, each patient had a tetracycline HCl loaded ethylene vinyl acetate co-polymer fiber placed into the periodontal pocket of 1 randomly selected tooth with persistent or recurrent periodontitis (test); the fiber was removed after 9.5+/-2.0 days. A non-adjacent tooth with persistent or recurrent periodontitis in a separate quadrant, which received no further treatment, served as a control. A total of 28 patients completed the 6-month study. Compared to control teeth, in test teeth at 6 months significantly (p<0.01) lower scores were found for gingival index, pocket probing depths, and PMN elastase-alpha1-proteinase inhibitor concentrations in gingival crevicular fluid. With the exception of plaque index scores, test teeth demonstrated significant reductions from baseline to 6 months in all parameters (p<0.05). Conversely, all parameter measurements in control teeth, except bleeding on probing, showed no significant difference between baseline and 6-month values. The results suggest that the use of controlled topical application of tetracycline HCl may improve periodontal health and reduce the risk of disease progression in localized persistent or recurrent periodontitis. Moreover, the effects of this application appear to be sustained for at least 6 months.

Evaluation of periodontal treatments using controlled-release tetracycline fibers: clinical response

The purpose of this investigation was to evaluate the clinical efficacy of controlled-release tetracycline fiber therapy in adult periodontitis patients. One hundred-twenty-two (122) adult patients from 3 dental centers were enrolled at baseline for this study. each patient provided at least one site in each of four quadrants that was > or = 5 mm and bled on probing. One or two such sites were selected as test sites and were randomly assigned to receive one of four treatments: scaling and root planing (S), scaling and root planing plus tetracycline fiber for 10 days (SF), fiber therapy alone for 10 days (F), or two 10-day serial fiber applications (FF). After treatment, no periodontal maintenance or supportive care was provided until the end of this 12-month study. Probing depth (PD), clinical attachment level (CAL), plaque, and bleeding on probing (BOP) were measured at baseline and at 1, 3, 6, 9, and 12 months following treatment. Repeated PD and CAL measurements were taken at three locations within each site and averaged for each site. One hundred-sixteen (116) subjects completed the study. All treatments resulted in similar improvements in clinical parameters compared to baseline and were equally effective in the treatment of periodontitis as measured by probing depth reduction, clinical attachment level gain, and reduction of bleeding on probing. The clinical response, established primarily by 3 months following therapy, was generally sustained in all treatment groups for 12 months without the benefit of supportive maintenance therapy.

Evaluation of periodontal treatments using controlled-release tetracycline fibers: microbiological response

In a 12-month multi-center study of 116 adult periodontitis subjects, six putative periodontal pathogens were monitored by DNA probe methods in a subset of 31 subjects. Monitored species included Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Fusobacterium nucleatum (Fn), Eikenella corrodens (Ec), Campylobacter rectus (Cr), and Actinobacillus actinomycetemcomitans (Aa) with an average detection limit of 1.8 x 10(4) bacterial colony forming units/sample. The microbiological response to four periodontal treatments was studied, one treatment in each quadrant; scaling and root planing (S), scaling and root planing with tetracycline (TC) fiber (SF), a single application of TC fiber (F) and two serial applications of TC fiber (FF). Generally two sites were sampled in each quadrant, however, in some quadrants only one site was selected. These treatments were evaluated at baseline; immediately following therapy; and post-treatment at 1, 3, 6, and 12 months. The study was conducted with a split-mouth design with no maintenance therapy over a 12-month period. At baseline, 70.8% of sites had detectable Fn; 42.9% Pg; 63.5% Pi; 29.7% Ec; 28.3% Cr; and 5.5% Aa. No significant differences were seen in baseline proportions of these species between centers. Numbers and proportions of detectable pathogens (with the exception of Pg) exhibited a triphasic temporal response: a precipitous initial decrease immediately following therapy; a rise in proportions in the 1- to 3-month post-therapy period; and a spontaneous decline in the absence of therapy over the 3- to 12-month period.(ABSTRACT TRUNCATED AT 250 WORDS)