Periodic subgingival antimicrobial irrigation of periodontal pockets. II. Microbiological and radiographical observations

Evaluation of the efficacy of subgingival irrigation in patients with moderate-to-severe chronic periodontitis otherwise indicated for periodontal flap surgeries

Background:

In certain medically and physically compromised; and terminally ill patients, periodontal surgery may not be feasible. They need special attention and assistance for their daily plaque control regimens for the management and maintenance of periodontal conditions. Subgingival irrigation home care devices with antiplaque agents may serve as useful tools in such specific patient populations.

Aims:

The aim of this study was to evaluate of the efficacy of sub-gingival irrigation in patients with moderate-to-severe chronic periodontitis otherwise indicated for periodontal flap surgeries.

Settings and Design:

Randomized comparative parallel group interventional clinical trial.

Materials and Methods:

Forty adults with moderate-to-severe periodontitis, divided inot Group A and B, were subjected to the use of subgingival home irrigations using 0.06% chlorhexidine (CHX) and mouth-rinsing with 15 ml of 0.12% CHX twice daily, respectively after Phase I therapy. Clinical parameters, i.e., gingival index, oral hygiene index simplified, and bleeding on probing scores were assessed at baseline, 2 weeks, 4 weeks, and 12 weeks’ postphase I therapy, whereas clinical attachment level (CAL), probing depth (PD), and stain assessment at baseline and 12 weeks following Phase I therapy.

Statistical Analysis Used:

Statistical Package for Social Sciences (SPSS Inc., Chicago, IL, USA version 15.0 for Windows).

Results:

A statistically significant difference was seen with the use of 0.06% CHX irrigations in PD (P = 0.004) and CAL (P = 0.002) as compared to the use of mouth rinsing with 0.12% CHX. Similar differences were observed in both intensity (P = 0.014) and area (P = 0.034) of lingual surface staining with greater staining with CHX mouth rinsing.

Conclusion:

The adjunctive use of subgingival home irrigations using 0.06% CHX has a promising potential to maintain the oral health and results in lesser staining compared to CHX mouth rinsing. The regimen may further obviate the need of periodontal surgery in medically compromised subjects.

Influences of microgap and micromotion of implant-abutment interface on marginal bone loss around implant neck

OBJECTIVE

To review the influences and clinical implications of micro-gap and micro-motion of implant-abutment interface on marginal bone loss around the neck of implant.

DESIGN

Literatures were searched based on the following Keywords: implant-abutment interface/implant-abutment connection/implant-abutment conjunction, microgap, micromotion/micromovement, microleakage, and current control methods available. The papers were then screened through titles, abstracts, and full texts.

RESULTS

A total of 83 studies were included in the literature review. Two-piece implant systems are widely used in clinics. However, the production error and masticatory load result in the presence of microgap and micromotion between the implant and the abutment, which directly or indirectly causes microleakage and mechanical damage. Consequently, the degrees of microgap and micromotion further increase, and marginal bone absorption finally occurs. We summarize the influences of microgap and micromotion at the implant-abutment interface on marginal bone loss around the neck of the implant. We also recommend some feasible methods to reduce their effect.

CONCLUSIONS

Clinicians and patients should pay more attention to the mechanisms as well as the control methods of microgap and micromotion. To reduce the corresponding detriment to the implant marginal bone, suitable Morse taper or hybrid connection implants and platform switching abutments should be selected, as well as other potential methods.

The antimicrobial sensitivity of Streptococcus mutans and Streptococcus sangius to colloidal solutions of different nanoparticles applied as mouthwashes

Background:

Metal nanoparticles have been recently applied in dentistry because of their antibacterial properties. This study aimed to evaluate antibacterial effects of colloidal solutions containing zinc oxide (ZnO), copper oxide (CuO), titanium dioxide (TiO₂) and silver (Ag) nanoparticles on Streptococcus mutans and Streptococcus sangius and compare the results with those of chlorhexidine and sodium fluoride mouthrinses.

Materials and Methods:

After adding nanoparticles to a water-based solution, six groups were prepared. Groups I to IV included colloidal solutions containing nanoZnO, nanoCuO, nanoTiO₂ and nanoAg, respectively. Groups V and VI consisted of 2.0% sodium fluoride and 0.2% chlorhexidine mouthwashes, respectively as controls. We used serial dilution method to find minimum inhibitory concentrations (MICs) and with subcultures obtained minimum bactericidal concentrations (MBCs) of the solutions against S. mutans and S. sangius. The data were analyzed by analysis of variance and Duncan test and P < 0.05 was considered as significant.

Results:

The sodium fluoride mouthrinse did not show any antibacterial effect. The nanoTiO₂-containing solution had the lowest MIC against both microorganisms and also displayed the lowest MBC against S. mutans (P < 0.05). The colloidal solutions containing nanoTiO₂ and nanoZnO showed the lowest MBC against S. sangius (P < 0.05). On the other hand, chlorhexidine showed the highest MIC and MBC against both streptococci (P < 0.05).

Conclusion:

The nanoTiO₂-containing mouthwash proved to be an effective antimicrobial agent and thus it can be considered as an alternative to chlorhexidine or sodium fluoride mouthrinses in the oral cavity provided the lack of cytotoxic and genotoxic effects on biologic tissues.

Biofilm removal and antimicrobial activity of two different air-polishing powders: an in vitro study

BACKGROUND

Biofilm removal plays a central role in the prevention of periodontal and peri-implant diseases associated with microbial infections. Plaque debridement may be accomplished by air polishing using abrasive powders. In this study, a new formulation consisting of erythritol and chlorhexidine is compared with the standard glycine powder used in air-polishing devices. Their in vitro antimicrobial and antibiofilm effects on Staphylococcus aureus, Bacteroides fragilis, and Candida albicans are investigated.

METHODS

Biofilm was allowed to grow on sandblasted titanium disks and air polished with glycine or erythritol-chlorhexidine powders. A semiquantitative analysis of biofilm by spectrophotometric assay was performed. A qualitative analysis was also carried out by confocal laser scanning microscopy. Minimum inhibitory concentrations and minimum microbicidal concentrations were evaluated, together with the microbial recovery from the residual biofilm after air-polishing treatment.

RESULTS

The combination of erythritol and chlorhexidine displayed stronger antimicrobial and antibiofilm activity than glycine against all microbial strains tested.

CONCLUSION

Air polishing with erythritol-chlorhexidine seems to be a viable alternative to the traditional glycine treatment for biofilm removal.

Photolysis of hydrogen peroxide, an effective disinfection system via hydroxyl radical formation

The relationship between the amount of hydroxyl radicals generated by photolysis of H(2)O(2) and bactericidal activity was examined. H(2)O(2) (1 M) was irradiated with laser light at a wavelength of 405 nm to generate hydroxyl radicals. Electron spin resonance spin trapping analysis showed that the amount of hydroxyl radicals produced increased with the irradiation time. Four species of pathogenic oral bacteria, Staphylococcus aureus, Aggregatibacter actinomycetemcomitans, Streptococcus mutans, and Enterococcus faecalis, were used in the bactericidal assay. S. mutans in a model biofilm was also examined. Laser irradiation of suspensions in 1 M H(2)O(2) resulted in a >99.99% reduction of the viable counts of each of the test species within 3 min of treatment. Treatment of S. mutans in a biofilm resulted in a >99.999% reduction of viable counts within 3 min. Other results demonstrated that the bactericidal activity was dependent on the amount of hydroxyl radicals generated. Treatment of bacteria with 200 to 300 μM hydroxyl radicals would result in reductions of viable counts of >99.99%.

An 8-week, randomized, controlled, clinical study of the use of a 0.1% chlorhexidine mouthwash by chronic periodontitis patients

AIM

  To evaluate the efficacy of a 2-week administration of a 0.1% chlorhexidine mouthwash in the short-term treatment of chronic periodontitis patients and the impact of this product when administered twice by pocket irrigation.

METHODS

  Sixty patients were enrolled in a single-centre, placebo-controlled, randomized study with the blind allocation of product to two parallel groups. Clinical assessments were performed, and samples from six selected subgingival sites were collected for microbial analysis by culture at baseline, D15 and D56. Three of the six sites were randomly selected and were treated by subgingival irrigation with the same 0.1% chlorhexidine product at D0 and D7. A subsequent statistical analysis was performed using the paired Student's t-test and Wilcoxon rank sum test for within-group analyses; analysis of variance and the Kruskall-Wallis test were used for between-group analyses.

RESULTS

  Two-week treatment with a 0.1% chlorhexidine mouthwash slightly reduced the gingival inflammation associated with periodontitis. We observed a significant decrease in Gram-negative, facultative anaerobes and micro-aerophiles, and a significant increase in Gram-positive cocci. No increase in the treatment effect was demonstrated by irrigation of the periodontal pockets.

CONCLUSION

  The 0.1% chlorhexidine mouthwash showed limited beneficial effects in the treatment of periodontitis patients.

Nonsurgical mechanical treatment strategies for periodontal disease

The comparison of the efficacy of surgical and nonsurgical procedures revealed that scaling and root planing alone or in combination with flap procedures are effective methods for the treatment of chronic periodontitis. Also, the consistent message is that in treating deep pockets, open-flap debridement results in greater probing pocket depth reduction and clinical attachment gain than nonsurgical modalities. Nonsurgical modalities in shallower pockets consistently involve less post-therapy recession and are clearly recognized as being more conservative. Research is still needed on the clinical benefit of the granulation tissue removal that is a feature of periodontal surgical therapy and, to a lesser extent, occurs through indirect trauma in nonsurgical therapy.

Periodontal Debridement With Povidone-Iodine in Periodontal Treatment: Short-Term Clinical and Biochemical Observations

BACKGROUND

The aim of the present study was to evaluate the clinical effects of one-stage periodontal debridement with an ultrasonic instrument, associated with 0.5% povidone (pvp)-iodine irrigation in patients with chronic periodontitis.

METHODS

Forty-five patients were randomly assigned into three groups: the control group (CG) received quadrant root planing at 1-week intervals over four consecutive sessions; the periodontal debridement plus pvp-iodine group (PD-PIG) received a 45-minute full-mouth debridement with an ultrasonic instrument, associated with 0.5% pvp-iodine irrigation; and the periodontal debridement group (PDG) received a 45-minute full-mouth periodontal debridement with an ultrasonic instrument, associated with NaCl irrigation.

RESULTS

At the 3-month evaluation, the mean probing depth (PD) reduction in CG was 2.51+/-0.52 mm, 2.53+/-0.50 mm in PD-PIG, and 2.58+/-0.60 mm in PDG (P<0.05). The clinical attachment level (CAL) analysis showed a statistically significant gain in all groups compared to baseline (1.87+/-0.56 mm [CG], 1.94+/-0.70 mm [PD-PIG], and 1.99+/-0.92 mm [PDG]). Intergroup analysis of PD and CAL at 1 and 3 months showed no differences (P>0.05). The N-benzoyl-L-arginine-p-nitroanilide (BAPNA) test showed a significant reduction in trypsin activity only during the first month (P<0.05); at 3 months there were no differences compared to baseline (P=0.80).

CONCLUSION

This study provides no evidence that pvp-iodine is effective as an adjunct for one-stage periodontal debridement.

Long-Term Clinical Effects of a Chlorhexidine Varnish Implemented Treatment Strategy for Chronic Periodontitis

BACKGROUND

Scaling and root planing in combination with oral hygiene monitoring are still considered the therapeutic standards for periodontitis. Although this treatment concept customarily results in satisfactory clinical improvements, treatment outcome may become less favorable predominantly when full access to periodontal defects is compromised, thereby leaving accretions behind. The purpose of this study was to investigate, over a 9-month period, the clinical benefits of a treatment strategy for chronic periodontitis based on a combination of sequential scaling and root planing and subgingival chlorhexidine varnish administration.

METHODS

This randomized controlled, single blind, parallel trial included 26 volunteers with chronic periodontitis. The control group received oral hygiene instructions and was scaled and root planed in two sessions. The test group received the same instructions and treatment; however, all pockets were additionally disinfected using a highly concentrated chlorhexidine varnish. Clinical response parameters were recorded at baseline and at 1, 3, 6, and 9 months. The impact of the initial strategy on the decision-making process for supplementary therapy at 9 months was investigated based on treatment decisions made by five independent clinicians.

RESULTS

Both treatment strategies showed significant reductions in probing depth and gains in clinical attachment at study termination in comparison with baseline (P<0.001). However, combination therapy resulted in a significant additional pocket reduction of 0.62 mm (P<0.001). Initially deep pockets (>or=7 mm) around multirooted teeth seemed to benefit most from the combination strategy, resulting in an additive pocket reduction of 1.06 mm (P=0.009) and a clinical attachment gain of 0.54 mm (P=0.048) in comparison to scaling and root planing alone. A trend toward a reduction of surgical treatment needs following the varnish-implemented strategy was found (P=0.076).

CONCLUSION

These findings suggest that the outcome of initial periodontal therapy may benefit from the adjunctive subgingival administration of a highly concentrated chlorhexidine varnish.

A Systematic Review on the Effects of the Chlorhexidine Chip When Used as an Adjunct to Scaling and Root Planing in the Treatment of Chronic Periodontitis

BACKGROUND

Several local antimicrobial agents, such as a bioabsorbable chlorhexidine chip, have been developed to enhance the outcome of non-surgical periodontal therapy.

METHODS

Electronic (MEDLINE and Cochrane Oral Health Group Specialized Trials Register) and manual searches were performed to detect studies concerning the use of the chlorhexidine chip as an adjunct to scaling and root planing in the treatment of chronic periodontitis. Only full-text randomized controlled trials published in English up to June 2005 were included.

RESULTS

Five studies were finally selected following independent screening by two reviewers. Due to considerable heterogeneity in study design, a qualitative data analysis was performed. Multicenter studies have indicated significantly higher pocket reductions and clinical attachment gains following a combination of mechanical debridement and repeated chlorhexidine chip administration in comparison to scaling and root planing alone. However, some recent studies failed to confirm the additional value of the chlorhexidine chip. A number of interstudy disparities with respect to methodological quality and study design may account for this lack of accordance.

CONCLUSIONS

The clinical and microbiological data currently available on the chlorhexidine chip are limited and conflicting. More research is needed to elucidate the additional value of the chlorhexidine chip when used as an adjunct to scaling and root planing.

Position Paper: The Role of Supra- and Subgingival Irrigation in the Treatment of Periodontal Diseases

This position paper addresses the role of supra- and subgingival irrigation in the treatment of periodontal diseases. It was prepared by the Committee on Research, Science and Therapy of the American Academy of Periodontology. The document is divided into two portions, consisting of supragingival irrigation and subgingival irrigation. In their respective segments, these treatment techniques are assessed as monotherapies and as adjuncts to conventional treatment. The conclusions drawn in this paper represent the position of the American Academy of Periodontology regarding irrigation therapy in the treatment of periodontal diseases.

A Systematic Review on the Effects of Subgingival Chlorhexidine Gel Administration in the Treatment of Chronic Periodontitis

BACKGROUND

Since scaling and root planing are not always successful, predominantly when access to periodontal defects is compromised, various antimicrobial agents as adjuncts have been suggested to enhance their efficacy. Gel vehicles delivering chlorhexidine (CHX) have become available and tested for these indications.

METHODS

An electronic (MEDLINE and Cochrane Oral Health Group Specialized Trials Register) and manual search were made to detect studies concerning the use of chlorhexidine gels as a single measure of treatment and as an adjunct to scaling and root planing. Only full-text randomized controlled trials published in English up to January 2005 were included.

RESULTS

Eight studies were finally selected. Due to considerable heterogeneity in study design and outcome variables measured a qualitative data analysis was performed. There is evidence that subgingival chlorhexidine gel administration as a monotherapy temporarily reduces bleeding tendency on probing; a clinical effect coinciding with relevant microbiological changes described in all but one study. To what extent chemical effects contribute to these changes appears to be related to the frequency of gel administration. There seem to be little to no data indicating that the treatment outcome of scaling and root planing will benefit from the adjunctive subgingival administration of a CHX gel.

CONCLUSION

The limited data currently available on the effects of subgingival chlorhexidine gel application do not justify its use in the treatment of chronic periodontitis.

Efficacy of subgingivally applied minocycline in the treatment of chronic periodontitis

BACKGROUND

The use of adjunctive minocycline with mechanical debridement in treating periodontitis has been widely studied using different methods. However, the results from these studies are equivocal.

OBJECTIVE

The purpose of this study was to clarify the efficacy of the adjunctive use of subgingival minocycline application plus scaling/root planing as compared with the results of one episode of scaling/root planing in the treatment of chronic periodontitis.

METHODS

Fifteen patients were enrolled in this split-mouth clinical trial. Probing depth, clinical attachment loss, gingival index, and bleeding on probing were evaluated at the baseline before scaling/root planing and 6, 10, 14, and 18 weeks later according to a single-blind protocol. The amount of interleukin-1beta (interleukin-1beta pg/site) at each lesion was also simultaneously measured in gingival crevicular fluid in a parallel comparison design. After full-mouth baseline measurements and scaling/root planing, 78 lesions with a residual mean probing depth of 5 mm at anterior teeth were selected and equally distributed in either right or left sites based on a split-mouth symmetrical design and randomly assigned to one of two treatment groups (with or without minocycline administration, n = 39 for each group).

RESULTS

Probing depth significantly decreased from the baseline (week 0) to week 6 after scaling/root planing (p < 0.05) in both groups, but there was no statistically significant difference between the two groups (p > 0.05). However, at weeks 10, 14, and 18, the experimental group showed significantly greater improvement in pocket reduction than the control group (p < 0.05). Similarly, both groups also showed significant decreases in gingival index scores from weeks 0-6 (p < 0.05), but gingival index reductions at weeks 10, 14, and 18 were statistically significant in favor of the experimental group (p < 0.05). The experimental group had more attachment gain than the control group at weeks 14 and 18 (p < 0.05). Values of interleukin-1beta (pg/site) at the experimental sites were significantly reduced at weeks 10, 14, and 18, as compared to values at control sites (p < 0.01). Finally, the incidence of bleeding on probing showed no differences between the two groups for any time interval (p > 0.05).

CONCLUSIONS

In this 18-week clinical trial, the results suggested that scaling/root planing with adjunctive subgingival administration of minocycline ointment has a significantly better and prolonged effect compared to scaling/root planing alone on the reduction of probing depth, clinical attachment loss, gingival index, and interleukin-1beta content, but not on bleeding on probing.

Quadrant root planing versus same-day full-mouth root planing. I. Clinical findings

OBJECTIVES

The aim of this study was to test the hypothesis that same-day full-mouth scaling and root planing (FM-SRP) resulted in greater clinical improvement compared to quadrant scaling and root planing (Q-SRP) in chronic periodontitis patients over a period of 6 months.

MATERIAL AND METHODS

Forty patients were recruited into this study. Subjects were randomised into two groups. The FM-SRP group received full-mouth scaling and root planing completed within the same day, while the Q-SRP group received quadrant root planing at 2-weekly intervals over four consecutive sessions. Whole-mouth clinical measurements were recorded with a manual periodontal probe at baseline (BAS) and at reassessment 1 (R1) (approximately 6 weeks after the completion of therapy), and at reassessment 2 (R2) (6 months after the initiation of therapy). Selected site analyses were performed on the deepest site in each quadrant before and after therapy (R1 and R2) and clinical indices were recorded with an electronic pressure sensitive probe. In addition, during the active phase of treatment clinical data were collected at 2-weekly intervals from the remaining untreated quadrants in the Q-SRP group only.

RESULTS

Both therapies resulted in significant improvements in all clinical indices both at R1 and R2. A continuous clinical improvement was seen for both treatment groups during the experimental period, which reached peak levels at 6 months (DeltaPD=1.8 mm, DeltaCAL=1.1 mm, p<0.001; PD: pocket depth; CAL: clinical attachment level). The selected-site analysis revealed no significant differences in any clinical index between the two treatment groups at R2 (DeltaPD=2.8 mm, DeltaRAL=1.1 mm; RAL: relative attachment level). At the selected sites, the analysis of the deep pockets (>7 mm) showed a significantly greater gain in RAL for the FM-SRP group compared to the Q-SRP group at R2 (p<0.05). The results of this analysis however, should be interpreted with care due to the small number of deep pockets. Data from the Q-SRP group provided an insight into how treated and untreated quadrants responded during the initiation of plaque control measures. There were significant reductions in PD, suppuration (SUP), modified gingival index (MGI) and plaque index (PI) in the remaining untreated quadrants in the Q-SRP group during the initial phase of treatment (p<0.05), while minimum changes in RALs and bleeding on probing (BOP) occurred. Nevertheless, the improvement in PD was clearly inferior to that seen after scaling and root planing.

CONCLUSION

Following both therapeutic modalities, there were marked clinical improvements at both R1 and R2 (6 months) from baseline. The current study, in contrast to previous findings, failed to show that FM-SRP is a more efficacious periodontal treatment modality compared to Q-SRP. However, both modalities are efficacious and the clinician should select the treatment modality based on practical considerations related to patient preference and clinical workload.

Use of antimicrobial agents during supportive periodontal therapy

Individual susceptibility to periodontal breakdown involves an interplay of genes, periodontal pathogens and other modulating factors. Anti-infective treatment, which includes oral hygiene measures, mechanical debridement, pharmacologic intervention and surgery, has been shown to be effective in arresting the progression of periodontal disease. Nevertheless, due to the chronic nature of the disease, susceptible individuals who are not maintained in a supervised recall program subsequent to the active treatment phase, show signs of recurrent destruction. Supportive periodontal therapy (SPT) is an integral part of periodontal treatment for patients with history of periodontitis, and is needed to prevent recurrence of disease in susceptible individuals. To prevent re-infection with periodontal pathogens, SPT includes elimination of dental plaque and bacteria from the oral cavity, thereby preventing the recurrence of pathogens into the gingival area. For individuals at risk of developing periodontitis, SPT should combine self-performed and professional anti-infective therapy, using mechanical and pharmacological means. The existing evidence suggests that the adjunctive use of antimicrobial pharmacologic therapy during SPT may enhance the results of mechanical debridement. The use of antimicrobials varies between patients, and is dependent on risk assessment and longitudinal monitoring of the clinical status of the periodontium.

Subgingival plaque removal at interdental sites using a low-abrasive air polishing powder

BACKGROUND

The aim of the study was to test the efficacy of a novel low-abrasive air polishing powder in subgingival plaque removal at interdental sites during periodontal maintenance therapy (PMT).

METHODS

Using a split mouth design, subgingival plaque was removed in 23 PMT patients using a low abrasive powder using a standard air polishing unit (test) or curets (positive control). Before and immediately after treatment, subgingival plaque samples were taken from interdental sites with 3 to 5 mm probing depth (PD) at 2 test teeth and 2 positive control teeth. To evaluate the influence of sampling on the microflora, plaque samples were also taken twice at 2 teeth without therapy with PD of 3 to 5 mm (negative control). PMT treatment and plaque sampling were repeated 3 times at quarterly intervals. Anaerobe cultivation was utilized to assess the mean reduction of total colony forming units (CFU) immediately after treatment.

RESULTS

Test treatment resulted in a significantly greater reduction in subgingival bacterial counts (log 1.9 +/- 0.7) than positive control treatment (log 1.1 +/- 0.6) and subgingival plaque sampling alone (log 0.5 +/- 0.5; P < 0.05). Differences between positive and negative control were not significant (P < 0.05).

CONCLUSION

The novel low-abrasive air polishing powder is superior to curets in removing subgingival plaque at interdental sites with up to 5 mm probing depth in PMT.

Full-mouth therapy versus individual quadrant root planning: a critical commentary

BACKGROUND

This commentary compares the abilities of full-mouth disinfection (FDIS), full-mouth root planing (FRP), and partial-mouth disinfection (PDIS) to improve periodontal health. FDIS consists of 4 quadrants of root planing completed within 24 hours with adjunctive chlorhexidine therapies (e.g., rinsing, subgingival irrigation, tongue brushing). FRP denotes 4 quadrants of root planing performed within 24 hours, and PDIS refers to root planing individual quadrants of the dentition, spaced 2 weeks apart. A basic premise of administering full-mouth therapy (FDIS or FRP) is to eliminate or reduce bacterial reservoirs within the oral cavity that could inhibit optimal healing of treated sites or cause periodontal disease initiation or progression.

METHODS

Controlled clinical trials that compared the abilities of PDIS and full-mouth root planing with and without adjunctive chlorhexidine chemotherapy to alter periodontal status were reviewed.

RESULTS

Several studies conducted at one treatment center indicated that FDIS and FRP attained greater therapeutic improvements than PDIS with respect to decreasing probing depths (PD), gaining clinical attachment (CAL), diminishing bleeding upon probing, and reducing the subgingival microflora. However, the magnitude of PD reductions and gains of clinical attachment must be carefully interpreted, because initial PD measurements were usually determined after scaling and root planing, which may have caused the results to be overstated. Furthermore, in studies that addressed the utility of FDIS, it was not possible to determine if benefits induced beyond PDIS were due to FRP or administration of multifaceted intraoral chlorhexidine treatments ora combination of both therapies. One investigation that had protocol limitations indicated that similar results were attained by FRP with and without adjunctive chemotherapy. In contrast, recent studies from 2 other treatment centers indicated that there were no significant differences when the efficacy of quadrant-by-quadrant root planing was compared to FRP or FDIS with regard to PD reduction, gains of clinical attachment, and impact on the magnitude and quality of the immune response. POSSIBLE CLINICAL IMPLICATIONS: Conceptually, full-mouth therapy (FRP or FDIS) could reduce the number of patient visits and facilitate more efficient use of treatment time. In addition, there appears to be no major adverse reactions to full-mouth root planing with or without adjunctive chemotherapy. However, small study populations and non-corroborating data from different treatment centers indicate that additional randomized clinical trials are needed to determine if full-mouth therapy provides clinically relevant improvements beyond PDIS.

Nonsurgical periodontal therapy in 2000: a literature review

BACKGROUND

This article addresses the advantages and limitations of nonsurgical periodontal therapies to treat patients with mild-to-moderate chronic periodontitis.

TYPES OF STUDIES REVIEWED

Controlled clinical trials were selected that assessed the efficacy of the following treatment methods: mechanical instrumentation, ultrasonic débridement, supragingival irrigation, subgingival irrigation, local drug delivery, administration of systemic antibiotics and host-response modulation. Evidently, data with regard to alterations of probing depth, clinical attachment levels and inflammatory status were evaluated.

RESULTS

Comparison of the data from test and control groups revealed the following results. Manual and ultrasonic débridement can be used to treat most patients with mild-to-moderate chronic periodontitis. Patients who do not practice optimal plaque control can enhance their personal hygiene procedures by using supragingival irrigation. Subgingival irrigation usually does not provide any benefit beyond that achieved with root planing. Systemic and locally delivered antimicrobial agents appear to be most beneficial among patients who do not respond to conventional treatment. Host modulation may enhance root planing modestly.

CLINICAL IMPLICATIONS

The data indicate that most patients with mild-to-moderate periodontitis can be treated with nonsurgical therapies. However, clinicians need to be aware of the limitations of each technique with regard to the magnitude of improvement that it can induce at specific sites.

Oral microflora as a cause of endocarditis and other distant site infections

Bacteremia originating from the oral cavity is common, but the role of bacteremia in the genesis of infective endocarditis and other distant site infections is unclear. Only a small percentage of oral flora have been associated with distant site infection. Important issues remain unresolved concerning the identification of patients at risk, the relative risk from invasive dental procedures versus naturally occurring bacteremia, and the impact of prophylactic antibiotics on the incidence, nature, magnitude, and duration of bacteremia from the oral cavity. This article addresses the controversies in infection management in patients at risk for distant site infection.

Effects of hydrogen peroxide on growth and selected properties of Porphyromonas gingivalis

In this study we first evaluated the effects of hydrogen peroxide (H2O2) on growth and selected properties of Porphyromonas gingivalis, and compared them with those obtained by a reducing agent (cysteine). The growth of P. gingivalis was only moderately affected when H2O2 was added at concentrations up to 30 mM in a complex culture medium. However, when a defined basal medium was used, H2O2 at a concentration of 3 mM completely inhibited growth of P. gingivalis. Incorporation of cysteine at concentrations up to 30 mM in both media had no effect on growth. The effects of H2O2 and cysteine on cell-associated hemagglutinating and Arg-gingipain activities were evaluated using bacteria grown in the complex culture medium. Both activities were strongly decreased when H2O2 was added in the assay mixtures. This inhibitory effect of H2O2 was reversible. On the other hand, including cysteine in the assay mixtures increased both activities. H2O2 and cysteine had no effect on the expression of heat shock protein (HSP)-68 and HSP-75 by P. gingivalis, as determined by SDS-PAGE and Western immunoblotting analysis. In the second part of the study, we tested whether growth of selected oral bacterial species may modify the oxidation-reduction potential (Eh) of the environment. It was found that certain species were able to either decrease (P. gingivalis, Fusobacterium nucleatum, Peptostreptococcus micros, Streptococcus mutans) or increase (Streptococcus sanguis) the Eh of the medium. Our study provides evidence that an oxidizing agent such as H2O2 may affect the biology of P. gingivalis. Moreover, growth of some members of the oral microflora can generate oxidizing and reducing conditions, and thus potentially influence the ecology of subgingival sites by affecting strictly anaerobic bacteria such as P. gingivalis.

Clinical and antimicrobial effects of a single episode of subgingival irrigation with tetracycline HCl or chlorhexidine in deep periodontal pockets

15 adults, each providing 4 non-adjacent untreated periodontal pockets with a probing depth (PD) exceeding 6 mm, volunteered for a randomized, split-mouth, double-blind, clinical study evaluating subgingival irrigation with chlorhexidine (CHX) or tetracycline HCl (TTC). The study protocol included oral hygiene instructions followed by scaling and root planing. Experimental and immediately adjacent teeth did not receive instrumentation. The 4 deep periodontal pockets in each patient were assigned to be irrigated with 150 ml CHX (0.12%), TTC (10 or 50 mg/ml; TTC10, TTC50), or sterile saline (control) in a single episode. Post-irrigation mechanical plaque control was supported by 2x daily CHX rinses throughout the 12-week observation interval. Recordings of oral hygiene (P1I), gingival health (GI), bleeding on probing (BoP), probing depth (PD), clinical attachment level (CAL), and microbial morphotypes from subgingival paper point samples were performed pre-irrigation, and at 1, 2, 4, 6, 8, 10, and 12 weeks post-irrigation. Mean post-irrigation P1I was low, fluctuating between 0.0 and 0.4, without significant differences between experimental groups. Mean pre-irrigation GI approximated 1.4 and reached 0.8 at the exit of study without significant differences between experimental groups. All experimental sites exhibited BoP pre-irrigation. BoP was significantly reduced in TTC50 compared to TTC10, CHX and control sites from week 8 post-irrigation. PDs were reduced for the experimental groups with TTC50 exhibiting the strongest reduction. CALs remained unaltered from pre-irrigation for TTC10, CHX and control sites over the 12-week observation interval, whereas TTC50 sites consistently improved to significantly differ from all other groups at week 10 and 12 post-irrigation. The distribution of bacterial morphotypes was significantly altered towards one of periodontal health for all experimental groups with a profound effect for TTC50 sites. Our results suggest that subgingival irrigation with TTC solutions at high concentrations may have a role in the management of adult periodontitis.

The effect of a one-stage full-mouth disinfection on different intra-oral niches. Clinical and microbiological observations

A treatment for periodontal infections often consists of consecutive rootplanings (per quadrant, at a 1- to 2-week interval), without a proper disinfection of the remaining intra-oral niches (untreated pockets, tongue, saliva, mucosa and tonsils). Such an approach, could theoretically lead to a reinfection of previously-treated pockets. The present study aims to examine the effect of a full-mouth disinfection on the microbiota in the above-mentioned niches. Moreover, the clinical benefit of such an approach was investigated. 16 patients with severe periodontitis were randomly allocated to a test and a control group. The patients from the control group were scaled and rootplaned, per quadrant, at 2-week intervals and obtained oral hygiene instructions. The patients from the test group received a full-mouth disinfection consisting of: scaling and rootplaning of all pockets in 2 visits within 24 h, in combination with tongue brushing with 1% chlorhexidine gel for 1 min, mouth rinsing with a 0.2% chlorhexidine solution for 2 min and subgingival irrigation of all pockets (3x in 10 min) with 1% chlorhexidine gel. Besides oral hygiene, the test group rinsed 2x daily with 0.2% chlorhexidine and sprayed the tonsils with a 0.2% chlorhexidine for 2 months. Plaque samples (pockets, tongue, mucosa and saliva) were taken at baseline and after 2 and 4 months, and changes in probing depth, attachment level and bleeding on probing were reported. The full-mouth disinfection resulted in a statistically significant additional reduction/elimination of periodontopathogens, especially in the subgingival pockets, but also in the other niches. These microbiological improvements were reflected in a statistically-significant higher probing depth reduction and attachment gain in the test patients. These findings suggest that a disinfection of all intra-oral niches within a short time span leads to significant clinical and microbiological improvements for up to 4 months.

Occurrence of invading bacteria in radicular dentin of periodontally diseased teeth: microbiological findings

Bacterial invasion in roots of periodontally diseased teeth, which has been recently documented using cultural and microscopic techniques, may be important in the pathogenesis of periodontal disease. The purpose of this investigation was to determine the occurrence and the species of invading bacteria in radicular dentin of periodontally diseased teeth. Samples were taken from the middle layer of radicular dentin of 26 periodontally diseased teeth. 14 healthy teeth were used as controls. Dentin samples were cultured anaerobically. The chosen methodology allowed the determination of the numbers of bacteria present in both deeper and outer part of dentinal tubules, and the bacterial concentration in dentin samples, expressed as colony forming units per mg of tissue (CFU/mg). Invading bacteria was detected in 14 (53.8%) samples from periodontally diseased teeth. The bacterial concentration ranged from 831.84 to 11971.3 CFU/mg (mean+/-standard deviation: 3043.15+/-2763.13). Micro-organisms identified included putative periodontal pathogens such as Prevotella intermedia, Porphyromonas gingivalis, Fusobacterium nucleatum, Bacteroides forsythus, Peptostreptococcus micros and Streptococcus intermedius. These findings suggest that radicular dentin could act as bacterial reservoir from which periodontal pathogens can recolonize treated periodontal pockets, contributing to the failure of therapy and recurrence of disease.

Clinical and microbiological effects of subgingival antimicrobial irrigation with citric acid as evaluated by an enzyme immunoassay and culture analysis

The purpose of the present study was to compare an enzyme immunoassay with culture samples from untreated and non-surgically treated periodontal pockets and to assess the clinical and microbiological effects of citric acid irrigation as a supplement to scaling and root planing. The enzyme immunoassay used in this study is a chairside diagnostic tool aimed at identifying the presence of P. gingivalis, P. intermedia, and A. actinomycetemcomitans. Six sites with pocket depths > or = 6 mm in each of 16 patients were monitored for 24 weeks using clinical and microbiological parameters. In two out of the six sites, scaling and root planing was supplemented with subgingival citric acid irrigation of the pocket after completion of the mechanical treatment. The sensitivity of the immunoassay in relation to culture was calculated to 85.5% and the specificity to 90.2%. The immunoassay corresponded to a detection level of 10(4) as estimated by culture. Sites treated with a combination of scaling and irrigation with citric acid demonstrated a similar healing pattern as sites treated with scaling and root planing alone. The profile of the marker bacteria was almost parallel for the two groups. The results of this investigation thus indicated that the immunoassay can be used as a screening tool for selected periodontal pathogens and that adjunctive irrigation with citric acid has no measurable clinical or microbiological effects.

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.

Full- versus partial-mouth disinfection in the treatment of periodontal infections. A pilot study: long-term microbiological observations

A standard periodontal treatment consists of 4 to 6 scalings and rootplanings at a 1- to 2-week interval, which allows reinfection of a previously disinfected area before completion of the treatment. The present pilot study aims to examine the microbiological long-term effects of a full-mouth disinfection. 10 patients with advanced chronic periodontitis were randomly allocated to a test and control group. The patients from the control group received scaling and rootplaning and oral hygiene instructions at a 2-week interval. The full-mouth disinfection (test group) consisted of a full-mouth scaling and rootplaning in 2 visits within 24 h in combination with: tongue brushing with 1% chlorhexidine gel for 1 min, mouth rinsing with 0.2% chlorhexidine solution for 2 min and subgingival irrigation of all pockets (3x in 10 min) with 1% chlorhexidine gel. The patients of the test group were instructed to rinse 2x daily with 0.2% chlorhexidine. Plaque samples were taken at baseline and after 1, 2, 4 and 8 months. Differential phase-contrast microscopy showed a significantly larger reduction of spirochetes and motile organisms in the test group up to month 2 for the single-rooted and up to month 8 for the multi-rooted teeth. Furthermore, the culture data supported the effectiveness of the new treatment strategy. In both groups, the number of anaerobic CFU decreased 1 log around single- and 0.5 log around multi-rooted teeth. The number of anaerobic CFU remained low in the test group, in contrast to the control group. At 1 month, the test group harboured a significantly (p<0.01) lower proportion of pathogenic organisms, but this difference disappeared with time. Moreover, the test sites showed a significantly higher (p<0.02) increase in the proportion of beneficial micro-organisms up to 4 months. These findings suggest that a full-mouth disinfection leads to a significant microbiological improvement up to 2 months, which could be consolidated, although not significant, for the next 6 months.

Treatment of periodontal disease based on microbiological diagnosis. Relation between microbiological and clinical parameters during 5 years

The purpose of this study was to assess the clinical effect of treatment aimed to suppress Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis below detection level and Prevotella intermedia below 5% of the cultivable periodontal pocket flora. Sixteen patients and a total of 111 periodontal pockets with probing depth > or = 6 mm were included in the study. Twelve patients and a total of 77 sites completed the 5-year study. The results demonstrated clinical improvement of probing depth and gain of clinical attachment level of 3.4 mm and 1.2 mm, respectively. Treatment to eliminate indicator bacteria continued for 3 years before the aim was fulfilled. In order to eliminate A. actinomycetemcomitans from a majority of the sites, a combination of surgery and generalized tetracycline treatment was performed. A recolonization or regrowth of the indicator bacteria exceeding detection levels took place in several sites. The presence of A. actinomycetemcomitans. P. gingivalis, and P. intermedia, alone or in combination, correlated with attachment level change on the individual level. No such correlation was obtained by using presence of plaque, bleeding on probing, or three other bacteria (Campylobacter rectus, Eikenella corrodens, and Fusobacterium nucleatum) not used as treatment goal markers.

Response to intracrevicular controlled delivery of 25% tetracycline from poly(lactide/glycolide) film strips in SPT patients

Controlled local delivery of antibiotics has been shown to reduce periodontopathic micro-organisms with minimal side-effects. Clinical studies in our laboratory have shown that 25% tetracycline HCl delivered from poly(D,L-lactide/glycolide) film strips (25 TTC-PLGA) released therapeutic concentrations of tetracycline for 10 days. The present pilot study compared the intracrevicular delivery of 25% tetracycline HCl incorporated in these biodegradable film strips to scaling and root planing (SRP) in 10 adult periodontitis patients, who in spite of therapy and regular supportive periodontal treatment (SPT), continued to possess 5 bleeding periodontal pockets at least 5 mm deep. Sites were randomly selected to receive the following treatments: (1) 25 TTC-PLGA, (2) control strips without TTC (PLGA), (3) SRP, and (4) untreated control. Film-strip retention was augmented with a suture/cement technique, followed by strip removal after 2 weeks. Clinical parameters and subgingival bacterial morphotypes (darkfield analysis) were evaluated over time (0, 2.4, 8, 12, 26 weeks). Results indicated that, compared to baseline, 25 TTC-PLGA film strips caused significant (p < or = 0.01): (1) probing depth reduction for 26 weeks, (2) a clinical attachment level gain for 12 weeks, (3) lower %s of spirochetes for 4 weeks and motile rods for 8 weeks (p < or = 0.05), and (4) an accompanying increase in cocci for 4 weeks. In the scaled and root planed sites, probing depth was the only finding that demonstrated a significant change from baseline (p < or = 0.01). Controls and PLGA showed isolated reductions in probing depth and % of motile organisms. From these findings, applications of intracrevicular 25 TTC-PLGA, when compared to scaling and root planing, appears to have an enhanced antibacterial effect and a similar clinical effect in SPT patients. The results of this study indicate further investigation of 25 TTC-PLGA film strips should be undertaken using more subjects and sophisticated microbiological and clinical measurements.

Clinical and microbiological changes associated with an altered subgingival environment induced by periodontal pocket reduction

The purpose of the present investigation was to study the effect of an altered subgingival environment, induced by changing the local soft tissue morphology, i.e., pocket depth reduction, on the subgingival microbiota and the clinical conditions. 7 patients aged 30-60 years with generalized marginal periodontitis were selected. Patients were instructed in proper oral hygiene and all teeth were cleaned supragingivally. Mucoperiosteal flaps were raised and the bone re-contoured to eliminate angular bony defects. While the control teeth were carefully debrided and thoroughly root planed, no root instrumentation was performed on the test teeth. Calculus deposits visible to the naked eye were only chipped-off with the tip of a scaler. The flaps were apically repositioned and sutured at the level of the bone crest. Clinical parameters showed a similar pattern of response in the test and control sites over a one year observation period post therapy. Probing depths and probing attachment levels were significantly reduced one month after surgery and remained at a lower level. A significant decrease was also noted for total anaerobic viable bacterial counts. The proportion of the Gram-negative anaerobic rods decreased significantly in both groups. P. gingivalis, Fusobacterium sp., C rectus were detected significantly less often after treatment in both groups. Capnocytophaga and A. odontolyticus, on the other hand, were more frequently isolated after therapy. These findings corroborate the concept that the reduction of selected subgingival microorganisms is the key element for the success of periodontal therapy, rather than the removal of tooth substance and mineralized deposits by root instrumentation.

Full- vs. partial-mouth disinfection in the treatment of periodontal infections: short-term clinical and microbiological observations

In a standard periodontal treatment strategy with consecutive root planings (per quadrant at a one- to two-week interval), re-infection of a disinfected area might occur before completion of the treatment. This study examines, both clinically and microbiologically, whether a full-mouth disinfection within 24 hours significantly improves the outcome of periodontal treatment. Ten patients with advanced chronic periodontitis were randomly allocated to a test and a control group. The patients from the control group received scalings and root planings as well as oral hygiene instructions per quadrant at two-week intervals. Full-mouth disinfection in the test group was sought by the removal of all plaque and calculus (in two visits within 24 hours). In addition, at each of these visits, the tongue was brushed with a 1% chlorhexidine gel for one min and the mouth rinsed with a 0.2% chlorhexidine solution for two min. Furthermore, subgingival chlorhexidine (1%) irrigation was performed in all pockets. The recolonization of the pockets was retarded by oral hygiene and 0.2% chlorhexidine rinses during two weeks. The clinical parameters were recorded, and plaque samples were taken from the right upper quadrant at baseline and after one and two months. The test group patients showed a significantly higher reduction in probing depth for deep pockets at both follow-up visits (p < 0.05). At the one-month visit, differential phase-contrast microscopy revealed significantly lower proportions of spirochetes and motile rods in the test group (p = 0.01). Culturing showed that the test group harbored significantly fewer pathogenic organisms at one month (p = 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

The effects on chronic periodontitis of a subgingivally-placed redox agent in a slow release device

Adjunctive chemical agents can reduce the need for meticulous plaque control. The aim of this investigation was to evaluate the periodontal treatment potential of subgingival application of the redox agent methylene blue in a slow-release device. This randomized, single-blind, split-mouth study included 18 patients aged 35-57 years, with chronic adult periodontitis, pocketing of at least 5 mm and radiographic evidence of regular bone loss. All experimental sites received subgingival debridement at day 0. Test sites received 32% w/w methylene blue in the slow release device at days 0 and 28. Clinical examination and microbiological sampling were performed at days 0, 7, 28, 56 and 84. Clinical improvements were seen in both groups, but test sites showed consistently greater improvements, some of which were statistically significant (as determined by between-group comparisons utilising SNDs). Significant between-group differences in relation to baseline levels were seen in bleeding index at days 7 and 56, in probeable pocket depth at day 56 and for the Perioscan BANA test at day 7. This pilot study thus showed that adjunctive methylene blue in a slow-release device can produce greater clinical and microbiological improvements than subgingival debridement alone.

DNA probe analyses of the survival of selected periodontal pathogens following scaling, root planing, and intra-pocket irrigation

This clinical study evaluated the survival rates of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia in periodontal pockets following scaling and root planing and intra-pocket irrigation with antimicrobial agents in patients with moderate and severe periodontitis. The number of target organisms was determined utilizing DNA probes. Adult periodontitis patients were selected on the basis that the subgingival flora contained at least one of the target organisms. Forty-eight (48) inflamed pockets > or = 5 mm in depth with probing attachment loss and containing at least one of the target species were then selected in 7 adult patients who harbored these bacteria. Following baseline clinical and bacterial examination, all patients received thorough scaling and root planing. In addition, 1 or 2 teeth in each patient which harbored the target flora at baseline were randomly assigned to each of the following 4 treatment modalities: 1) control group, no irrigation; 2) saline group, irrigation with 2 cc of physiologic saline; 3) tetracycline group, irrigation with 2 cc of aqueous tetracycline hydrochloride, 50 mg/ml (5%); and 4) chlorhexidine group, irrigation with 2 cc 0.12% chlorhexidine. All selected sites (5 to 8 per patient) were nonadjacent teeth. Clinical parameters and microbial analysis were recorded again at one week, and one month post-irrigation. The survival rate of the target microorganisms was determined and the effect of irrigation with antimicrobial agents on this microflora was compared with the control groups (1 and 2).(ABSTRACT TRUNCATED AT 250 WORDS)

Short-term microbiological and clinical effects of subgingival irrigation with an antimicrobial mouthrinse

Fifty chronic adult periodontitis patients completed a 6-week controlled, double-blind, split mouth clinical study to determine the effects of subgingival irrigation with an antimicrobial mouthrinse on periodontal microflora, supragingival plaque, and gingivitis when used as an adjunct to normal oral hygiene. Qualifying subjects had at least four sites, two on each side of the mouth, with probing depths between 4 and 6 mm, which bled on gentle probing. Following baseline examinations, subjects received a half mouth scaling and prophylaxis and full mouth subgingival irrigation with either the antimicrobial mouthrinse or sterile colored water control professionally delivered. Subjects continued irrigation at home once daily for 42 days with their assigned rinse delivered via a subgingival delivery system. All sites in the mouth were scored at baseline and at day 42 for supragingival plaque, bleeding on probing, and redness. For the four selected periodontitis sites, probing depth and attachment level were measured at baseline and on day 42; additionally, supragingival plaque and gingival redness were scored on days 7 and 21. Subgingival plaque samples for microbiological analysis were harvested from the selected periodontal sites at baseline and on days 7, 21, and 42. Microbiologically, irrigation with the antimicrobial mouthrinse resulted in statistically significant reductions compared to control in putative periodontopathogens, including black pigmenting species, which persisted at 42 days. Clinically, subgingival irrigation with the antimicrobial mouthrinse produced a significant reduction in supragingival plaque (P < 0.001), bleeding on probing (P = 0.019), and redness (P = 0.017) compared to the control, whether or not the area irrigated received a prophylaxis.(ABSTRACT TRUNCATED AT 250 WORDS)

Antimicrobial properties of human dentin impregnated with tetracycline HCl or chlorhexidine. An in vitro study

Substantivity of tetracycline HCl and chlorhexidine digluconate to human root dentin was assessed in vitro. 51 extracted single-rooted teeth, their crowns removed, were assigned to 1 of 4 treatments in groups of 12. A control groups included 3 roots. Each group was divided into 3 subgroups to allow evaluation of drug exposure for 1, 3 or 5 min. The roots were immersed in tetracycline HCl (10 or 50 mg/ml) or chlorhexidine digluconate (0.12 or 0.2%) solutions following root planning. Control roots were immersed in sterile saline (0.9%). Following drug immersion, the roots were transferred to tubes containing 2 ml tris buffered saline. The tubes were incubated at room temperature for 22 days. Desorption media were replaced at 24-h intervals. Removed media were examined for antimicrobial activity using a microtiter assay in which bacterial growth was evaluated by optical density readings. Roots immersed in tetracycline HCl 50 mg/ml released antimicrobial activity to successive desorption media for 14 days. Tetracycline HCl 10 mg/ml activity lasted 4 days. Roots subjected to chlorhexidine digluconate released antimicrobial activity for 24 h only. Within each treatment, there were no differences between the 3 exposure intervals of 1, 3 or 5 min. Our findings suggest usage of the periodontally exposed instrumented root as a depot for sustained release of tetracycline HCl, but not chlorhexidine digluconate, to the subgingival environment. The substantiveness of tetracycline HCl seems related to drug concentration rather than the exposure interval. Clinical trials are needed to confirm the clinical significance of these in vitro observations.

The role of subgingival irrigations in the treatment of periodontitis

While the efficacy of oral irrigations with antimicrobial agents on the clinical and microbial parameters of gingivitis is well established, the study of the efficacy of intrapocket irrigants on periodontitis has yielded conflicting and inconclusive results regarding both clinical and microbiological parameters. The overall goal of this review paper is to summarize the available information on the efficacy of intrapocket irrigation in the treatment of patients with periodontitis. The following topics are addressed: 1) the penetrability of the irrigant; 2) pocket irrigation without scaling and root planing; 3) professional pocket irrigation following scaling and root planing; 4) irrigations between recalls; and 5) safety of intrapocket irrigation. Single irrigation of periodontal pockets for short periods of time before or after scaling and root planing has limited effects on periodontal healing. However, continuous irrigation of the periodontal lesion with agents such as povidone iodine during thorough scaling and root planing, such as that carried out under local anesthesia, has promise as an antimicrobial adjunct in periodontal therapy.

Clinical effects of simultaneous ultrasonic scaling and subgingival irrigation with chlorhexidine. Mediating influence of periodontal probing depth

The clinical and microbial effects of a single episode of simultaneous ultrasonic scaling and subgingival irrigation with chlorhexidine (CHX) were studied as a function of clinical probing depth in patients with adult periodontitis. 60 patients were randomly assigned to receive subgingival irrigation under cavitation with either sterile water or 0.12% CHX delivered through the tip of an ultrasonically activated scaler as part of initial periodontal therapy in a double-blind study design. 3 periodontal sites were randomly selected for examination from each patient on the basis of clinical probing depth, with 1 site being selected within each of the following ranges: 1-3 mm, 4-6 mm, and 7-9 mm. Pretreatment and post-treatment (days 14 and 28) clinical assessments included a plaque index (PI), gingival index (GI), and clinical probing depth (CPD). Subgingival specimens also were collected from 1-3 mm and 4-6 mm sites on a random subset of patients (15 per group). Plaque counts of spirochetes and motile organisms were made by darkfield microscopy. Significant reductions in PI, GI, and CPD were observed among all sites within both treatment groups at 14 and 28 days post-treatment. CHX irrigation resulted in a significantly greater reduction in CPD than did water among sites initially probing 4-6 mm at both 14 and 28 days post-treatment (25% versus 13% and 31% versus 18%, respectively). Spirochete counts were modestly but nonsignificantly reduced at 14 days post-treatment among sites 4-6 mm within both treatment groups. These results suggest that subgingival irrigation with CHX during ultrasonic scaling provides differential clinical benefits that are site-dependent.