The effect of mouthrinses on parameters characterizing human periodontal disease

Chlorhexidine mouthwash as an adjunct to mechanical therapy in chronic periodontitis: A meta-analysis

BACKGROUND

Through a systematic literature review, the authors evaluated the use of chlorhexidine (CHX) mouthwash as an adjunct to mechanical periodontal therapy for chronic periodontitis.

TYPES OF STUDIES REVIEWED

The authors performed a systematic search by using PubMed (MEDLINE), Scopus, Scientific Electronic Library Online, and Cochrane Central Register of Controlled Trials. The authors selected randomized controlled clinical trials in which the investigators evaluated the probing depth (PD) and clinical attachment level (CAL) in test groups by using CHX as an adjuvant and in control groups and subject to mechanical periodontal therapy (scaling and root planing [SRP] 4-6 visits or 24 hours).

RESULTS

The literature search resulted in 8 articles, which the authors then assessed for quality. After testing for heterogeneity, the authors performed a meta-analysis only in the SRP group with 4 to 6 visits. Results were positive for both PD and CAL with use of CHX. However, the summary measure was significant (P < .05) only for PD at 40 to 60 days (0.33 millimeters; 95% confidence interval, 0.08 to 0.58 mm) and 180 days (0.24 mm; 95% confidence interval, 0.02 to 0.47 mm) of follow-up, showing positive results for the use of CHX at those times. Although those differences were statistically significant, they could be interpreted as clinically slight.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

Adjunctive use of CHX mouthrinse with mechanical SRP resulted in slightly greater PD reduction than did SRP alone. Clinicians must consider the small additional gain in PD reduction, negligible effect on CAL, and potential for tooth staining when using CHX as an adjunct to SRP in treating chronic periodontitis.

Antibacterial effects of blackberry extract target periodontopathogens

BACKGROUND AND OBJECTIVE

Antimicrobial agents provide valuable adjunctive therapy for the prevention and the control of oral diseases. Limitations in their prolonged use have stimulated the search for new, naturally occurring agents with more specific activity and fewer adverse effects. Here we sought to determine the antibacterial properties of blackberry extract (BBE) in vitro against oral bacterial commensals and periodontopathogens.

MATERIAL AND METHODS

The effects of whole and fractionated BBE on the metabolism of 10 different oral bacteria were evaluated using the colorimetric water-soluble tetrazolium-1 assay. The bactericidal effects of whole BBE against Fusobacterium nucleatum were determined by quantitating the numbers of colony-forming units (CFUs). Cytotoxicity was determined in oral epithelial (OKF6) cells.

RESULTS

BBE at 350-1400 μg/mL reduced the metabolic activity of Porphyromonas gingivalis, F. nucleatum and Streptococcus mutans. The reduced metabolic activity observed for F. nucleatum corresponded to a reduction in the numbers of CFUs following exposure to BBE for as little as 1 h, indicative of its bactericidal properties. An anthocyanin-enriched fraction of BBE reduced the metabolic activity of F. nucleatum, but not of P. gingivalis or S. mutans, suggesting the contribution of species-specific agents in the whole BBE. Oral epithelial cell viability was not reduced following  exposure to whole BBE (2.24-1400 μg/mL) for ≤ 6 h.

CONCLUSION

BBE alters the metabolic activity of oral periodontopathogens while demonstrating a minimal effect on commensals. The specific antibacterial properties of BBE shown in this study, along with its previously demonstrated anti-inflammatory and antiviral properties, make this natural extract a promising target as an adjunct for prevention and/or complementary therapy of periodontal infections.

The cost-effectiveness of a new chlorhexidine delivery system in the treatment of adult periodontitis

BACKGROUND

Periodontal treatment is costly. The authors assessed the potential economic impact of a new periodontal chemotherapeutic, testing the hypothesis that its adjunctive use would result in reduced periodontal surgical needs.

METHODS

An economic model estimated treatment needs following two clinical trials of the adjunctive use of a chlorhexidine, or CHX, -containing chip compared with scaling and root planing, or SRP, alone. Needs were based on periodontal status at nine months and a probabilistic algorithm; costs were assigned on the basis of a national dental survey and an average wholesale price of the CHX chip.

RESULTS

The base case model projected significantly more maintenance procedures and significantly fewer periodontal surgical procedures for patients treated with SRP and the CHX chip compared with patients who were treated with SRP alone (54.4 percent vs. 46.4 percent, P = .014; 29.2 percent vs. 35.5 percent, P = .015, respectively). Average total costs of care for patients treated with SRP and CHX chip were $737 +/- $244 compared with $734 +/- $239 for patients treated with SRP alone. Sensitivity analyses to account for variations in practice patterns did not appreciably alter the results. When data were analyzed after only three or six months of treatment, the significant differences in treatment needs disappeared.

CONCLUSIONS

The CHX chip is a new, apparently cost-effective treatment option for non-surgical periodontal therapy. Adjunctive use of the CHX chip could reduce periodontal surgical needs significantly at little or no additional cost.

CLINICAL IMPLICATIONS

Results suggest that incorporating the CHX chip into routine practice requires a new algorithm for management of periodontal disease. To obtain full clinical benefit, treatment needs to be continued for nine months.

Antibacterial agents in the control of supragingival plaque--a review

This review considers the main agents which have been used as antibacterial agents in mouthwashes and other vehicles to inhibit the growth of supragingival plaque. The agents discussed are bisguanide antiseptics, quaternary ammonium compounds, phenolic antiseptics, hexetidine, povidone iodine, triclosan, delmopinol, salifluor, metal ions, sanguinarine, propolis and oxygenating agents. The plaque inhibitory, anti-plaque and anti-gingivitis properties of these agents are considered along with their substantivity, safety and possible clinical usefulness. Clinical trials of these agents that have been published are also reported. The possible clinical uses of antiseptic mouthwashes are finally considered along with some advice about assessing manufacturers claims. Throughout this review the terms plaque inhibitory, anti-plaque and anti-gingivitis have been used according to the clarification of terminology suggested by the European Federation of Periodontology at its second workshop. This defines a plaque inhibitory effect as one reducing plaque to levels insufficient to prevent the development of gingivitis; an anti-plaque effect as one which produces a prolonged and profound reduction in plaque sufficient to prevent the development of gingivitis; and anti-gingivitis as an anti-inflammatory effect on the gingival health not necessarily mediated through an effect on plaque.

The use of locally delivered chlorhexidine in the treatment of periodontitis. Clinical results

Since the advent of a nondegradable controlled local delivery of antibiotics in 1979, several second generation systems have been developed. Second generation systems have attempted to improve on the early system. Chlorhexidine has been used effectively for over 30 years as an antiseptic. In the early 1970s, chlorhexidine gluconate was incorporated at 0.2% into mouthrinses in Europe and in 1986 it was incorporated at 0.12% in a mouthrinse in the United States. Since these mouthrinses were effective in reducing the supragingival flora, had a high safety margin, and had no reported bacterial resistance, chlorhexidine offered a therapeutic advantage for a local delivery system. This system was developed and studied. This report will discuss this new biodegradable system containing chlorhexidine gluconate as the active agent (PerioChip). Pharmacokinetics of the system and a review of the multicenter studies in Europe and the United States are discussed. In these randomized clinical trials the chlorhexidine chip has been shown to enhance the effects of scaling and root planing. Chlorhexidine chip in conjunction with scaling and root planing, when compared to scaling and root planing alone, has shown significant improvement in probing pocket depth reduction, probing attachment level and bleeding on probing. This delivery system, in combination with scaling and root planing, has also resulted in significantly more probing depth reductions of 2 mm or more. The system is safe and efficacious. Placement of the chip is usually done in less than 1 min, it requires no retention system, biodegrades, and does not require a follow-up dental appointment.

Adjunctive use of a subgingival controlled-release chlorhexidine chip reduces probing depth and improves attachment level compared with scaling and root planing alone

The present studies evaluated the efficacy of a controlled-release biodegradable chlorhexidine (CHX) (2.5 mg) chip when used as an adjunct to scaling and root planing on reducing probing depth (PD) and improving clinical attachment level (CAL) in adult periodontitis. Two double-blind, randomized, placebo-controlled multi-center clinical trials (5 centers each) were conducted; pooled data are reported from all 10 centers (447 patients). At baseline, following 1 hour of scaling and root planing (SRP) in patients free of supragingival calculus, the chip was placed in target sites with PD 5 to 8 mm which bled on probing. Chip placement was repeated at 3 and/or 6 months if PD remained > or = 5 mm. Study sites in active chip subjects received either CHX chip plus SRP or SRP alone (to maintain study blind). Sites in placebo chip subjects received either placebo chip plus SRP or SRP alone. Examinations were performed at baseline; 7 days; 6 weeks; and 3, 6, and 9 months. At 9 months significant reductions from baseline favoring the chlorhexidine chip compared with both control treatments were observed with respect to PD (chlorhexidine chip plus SRP, 0.95 +/- 0.05 mm; SRP alone, 0.65 +/- 0.05 mm, P < 0.001; placebo chip plus SRP, 0.69 +/- 0.05 mm, P < 0.001) and CAL (chlorhexidine chip plus SRP, 0.75 +/- 0.06 mm; SRP alone, 0.58 +/- 0.06 mm, P < 0.05; placebo chip plus SRP, 0.55 +/- 0.06 mm, P < 0.05). The proportion of patients who evidenced a PD reduction from baseline of 2 mm or more at 9 months was significantly greater in the chlorhexidine chip group (19%) compared with SRP controls (8%) (P < 0.05). Adverse effects were minor and transient toothache, including pain, tenderness, aching, throbbing, soreness, discomfort, or sensitivity was the only adverse effect that was higher in the chlorhexidine group as compared to placebo (P = 0.042). These data demonstrate that the adjunctive use of the chlorhexidine chip results in a significant reduction of PD when compared with both SRP alone or the adjunctive use of a placebo chip. These multi-center randomized control trials suggest that the chlorhexidine chip is a safe and effective adjunctive chemotherapy for the treatment of adult periodontitis.

Effects of sanguinarium, chlorhexidine and tetracycline on neutrophil viability and functions in vitro

The effectiveness of an ideal antimicrobial agent depends on its ability to kill microbes with minimal toxicity to host cells. Depending on the treatment regimen, antimicrobial agents come into contact with host cells for various intervals of time. Sanguinarium (SANG), chlorhexidine (CHX) and tetracycline (TET) are 3 antimicrobial agents frequently used in the management of periodontal infections. However, their effects on host immune cells during different treatment regimens are not known. Due to their ability to serve as the first line of host defense against microbial infections, we have compared the effects of these antimicrobial agents on human neutrophil functions and viability. The results show that SANG is not lytic to neutrophils from peripheral blood or crevicular fluid, at all concentrations tested. However, exposures of neutrophils to very low concentrations of SANG (0.001%) inhibits neutrophil chemotaxis, oxidative metabolism and degranulation within 5 min. Increasing the exposure time results in a similar inhibition of neutrophil functions, albeit at 50-100 fold lower concentrations of SANG. CHX rapidly disrupts the cell membrane of both crevicular and peripheral blood neutrophils at concentrations above 0.005% within 5 min, and inhibition of all neutrophil functions is due to its lytic properties. While TET is least toxic to neutrophils, a dose dependent inhibition of neutrophil functions is dependent on the calcium concentrations of the cellular environment, and is observed only above 0.04% or higher concentrations in the absence of calcium. The data suggest that a critical cumulative concentration of these drugs is essential for their toxicity and inhibition of neutrophil functions. Therefore, both the length of exposure and the dose of the drug both are critical while considering the effectiveness of SANG, CHX or TET in the treatment of infections. Furthermore, due to differences in their mechanisms of action, the consequences of their effects on neutrophils may have significant bearing on tissue pathology as well as on their therapeutic efficacy.

Efficacy of a dentifrice and oral rinse containing sanguinaria extract in conjunction with initial periodontal therapy

In the treatment of periodontal disease initial therapy aims at reducing marginal inflammation so allowing assessment of residual disease and further treatment options. The aim of the present study was to determine whether the use of a dentifrice and oral rinse containing sanguinaria extract led to a more rapid resolution of gingival inflammation following initial therapy. Thirty-four subjects, randomly assigned to one of two treatment groups, took part in this randomized double-blind parallel study. All subjects received initial therapy including oral hygiene instruction and scaling and root planing as required. One group also received an active dentifrice and oral rinse containing sanguinaria extract (an antiplaque agent) and zinc chloride. The other group received a placebo dentifrice and oral rinse. The gingival index (GI), plaque index (PLI) and probing pocket depths (PD) were recorded at six sites per tooth at baseline, two weeks after initial therapy and six weeks after initial therapy. There was no significant difference between the groups for any of the parameters at the baseline examination. Two weeks following initial therapy both groups showed a statistically significant increase in the number of sites with PLI of 0 or 1 (p < 0.0001) and a statistically significant increase in the number of sites with a GI of 0 or 1 (that is, no bleeding on probing), (p < 0.0001). Also there was a statistically significant increase in the number of sites with probing depths < or = 3 mm (p < 0.0001) compared with baseline. These changes were maintained through to six weeks post therapy. There was no significant advantage to the sanguinaria group. Results demonstrate that initial therapy in the form of oral hygiene instruction, scaling and root planing leads to a significant improvement in periodontal status which is maintained at least in the short term. Further, use of a dentifrice and oral rinse containing sanguinaria did not improve the efficacy of initial therapy.

Adjunctive supragingival irrigation with acetylsalicylic acid in periodontal supportive therapy

To assess the clinical efficacy of adjunctive supragingival irrigation with buffered 0.3% acetylsalicylic acid (ASA), 60 patients with periodontitis receiving supportive periodontal therapy were randomly assigned to 1 of 3 home regimens: (1) 1x daily adjunctive supragingival irrigation with 300 ml water immediately followed by 200 ml of buffered 0.3% ASA; (2) 1x daily adjunctive supragingival irrigation with 500 ml water; or (3) normal oral hygiene alone. Clinical parameters were assessed at baseline and 6 months. Irrigator use was measured by timers built into the irrigator units. Results at 6 months showed that both supragingival irrigation with buffered 0.3% ASA and supragingival irrigation with water significantly reduced gingival index scores (median 0.1 and 0.35, respectively) and pocket probing depths (both median 0.26 mm) compared to the control group. In addition, irrigation with water resulted in a significant reduction in bleeding on probing (median 0.13), whereas irrigation with buffered 0.3% ASA had no significant effect on bleeding on probing compared to the control group. The clinical efficacy of irrigation with either ASA or water was found to be positively correlated to initial disease severity and irrigator use. Thus, frequent supragingival irrigation with either 0.3% ASA or water in addition to regular oral hygiene appears to be a beneficial adjunct to periodontal supportive therapy in patients with moderate to severe signs of periodontitis. However, the use of buffered 0.3% ASA as an irrigant does not seem to enhance the clinical efficacy of supragingival irrigation on periodontal health.

Pharmacological control of periodontal disease. I. Antiplaque agents

Inhibition of the development of dental plaque remains one of the primary aims of periodontal care. Many patients, however, are unable to master completely the mechanical methods of plaque control and for this reason, considerable research efforts have been directed towards the development and use of chemical agents to inhibit the growth of plaque. This first of two articles, therefore, examines the pharmacological properties and efficacy of commercially available antiplaque agents. We have also summarized the findings of some of the major clinical trials that have provided the scientific basis for the introduction of these agents for the management of gingival inflammation.

Gingival enhancement in fixed prosthodontics. Part III: Anamnestic findings

This study obtained anamnestic data from a questionnaire given at the conclusion of a 7-week chlorhexidine gingival enhancement study regarding patients' oral hygiene practices, perception of change in gingival health, and side effects. In the patient population using the 7-week chlorhexidine treatment regimen, most patients noticed an improvement in gingival health, were willing to continue usage after the study, and would recommend the rinse to others. Of the patients who reported side effects, taste alteration was more objectionable than staining. The patients' observed gingival health benefits were more important than the patients' perception of the side effects such as staining and taste alteration.

Gingival enhancement in fixed prosthodontics. Part II: Microbiologic findings

This study assessed the changes of the subgingival/marginal microflora during fixed prosthodontic procedures and evaluated the effect of adjunctive rinsing with 0.12% chlorhexidine on the subgingival/marginal microflora during fixed prosthodontic treatment. Thirty patients scheduled for fixed prosthodontics were randomly assigned to either rinsing with 15 ml of tap water b.i.d. (control) or rinsing with 15 ml of 0.12% chlorhexidine gluconate b.i.d. (experimental). Subgingival and marginal plaque was analyzed at baseline, before crown preparation (2 weeks), before crown cementation (5 weeks), and 2 weeks after cementation (7 weeks). The fixed prosthodontic procedures alone altered the subgingival and marginal microbiota toward a more health-associated flora. Adjunctive rinsing twice daily with 0.12% chlorhexidine had a significantly greater effect in reducing putative periodontal pathogens compared with the control regimen. This medication was a useful adjunct to regular oral hygiene during fixed prosthodontic procedures by permitting the establishment and maintenance of a microflora compatible with periodontal health.

Clinical efficacy of a dentifrice and oral rinse containing sanguinaria extract and zinc chloride during 6 months of use

The efficacy of combined use of toothpaste and oral rinse containing sanguinaria extract and zinc chloride was compared to placebo products in a 6-month clinical trial. Sixty subjects with moderate levels of plaque and gingivitis were randomly assigned to active and placebo groups. Noninvasive measures of plaque and gingivitis were assessed at baseline and at 2, 6, 8, 14, 20, and 28 weeks. Bleeding on probing was measured at baseline and 6, 14, and 28 weeks. Active group scores were significantly lower (P less than .0001) than placebo scores at each post-baseline time point for all indices, with the exception of plaque at 2 weeks. The 28 week active group scores were 21% lower than the placebo group for plaque, 25% lower for gingivitis, and 43% lower for bleeding on probing. No dental staining or taste alteration was reported in the active group. Three of 30 active group subjects exhibited minor soft tissue irritations that resolved spontaneously without discontinuation of product use. Results indicate that the test products showed good levels of safety and efficacy when administered in a combined use regimen for 6 months.

Effect of 6 months use of a dentifrice and oral rinse containing sanguinaria extract and zinc chloride upon the microflora of the dental plaque and oral soft tissues

This study documented the effect upon the oral flora of twice daily brushing with a dentifrice containing 0.075% sanguinaria extract and 2% zinc chloride, followed by use of a mouthrinse containing 0.03% sanguinaria extract and 0.2% zinc chloride. Sixty subjects were randomly assigned to treatment or placebo groups and monitored in a 6-month double-blind clinical trial. Bacteriological samples from the tongue, buccal mucosa, and supra- and subgingival plaque were characterized at 0, 14, and 28 weeks. Microbiological monitoring showed no increases in populations of yeast, staphylococci, coliform organisms, or Pseudomonas. Total Gram-negative counts in supragingival plaque samples decreased 83% in the active group compared to a 232% increase for the control group. Populations of B. intermedius in supragingival plaque were significantly lower in the active group at 3 months and significantly lower counts of Fusobacterium sp. were observed at 3 and 6 months. Results indicate that use of the test products did not promote opportunistic overgrowth of pathogens in the oral flora. Additionally, the alterations in organisms associated with gingivitis may account for reductions in gingivitis seen in the active group.

Long-term clinical evaluation of toothpaste and oral rinse containing sanguinaria extract in controlling plaque, gingival inflammation, and sulcular bleeding during orthodontic treatment

A sanguinaria-containing toothpaste and oral rinse regimen was evaluated during a 6-month period to determine its effectiveness in controlling plaque, gingival inflammation, and sulcular bleeding. Oral hygiene instructions and a 1-month prestudy brushing period failed to produce a significant improvement in health among the 24 subjects as determined by the three evaluation parameters. After the oral hygiene period, the subjects were randomly assigned to the active treatment (marketed Viadent toothpaste and oral rinse) or the placebo treatment (same base formulas without sanguinaria). Treatments were evaluated using the Löe and Silness gingival index, the Silness and Löe plaque index, and the Mühlemann and Son sulcular bleeding index at baseline and monthly through 6 months. The sanguinaria regimen reduced plaque by 57%, gingival inflammation by 60%, and sulcular bleeding by 45% from baseline compared with placebo group reductions of 27% (plaque) and 21% (gingival inflammation), and an increase of 30% in bleeding index. Repeated-measures analysis of covariance with baseline scores used as covariates showed statistically significant differences at 6 months for plaque (active 0.39; placebo 0.68, p less than 0.01), gingival inflammation (active 0.32; placebo 0.76, p less than 0.001), and sulcular bleeding (active 0.34; placebo 0.70, p less than 0.002). Results of this study demonstrated that the combined use of the sanguinaria-containing toothpaste and oral rinse controls and reduces plaque and gingival inflammation in an orthodontic population.

A clinical trial to assess the efficacy of sanguinarine-zinc mouthrinse (Veadent) compared with chlorhexidine mouthrinse (Corsodyl)

A single-blind crossover study was used to compare the ability of a 0.2% chlorhexidine mouthrinse (Corsodyl) with a sanguinarine-zinc mouthrinse (Veadent) to inhibit plaque and gingivitis. 14 volunteers starting with plaque-free mouths and optimal gingival health, rinsed with the preparations over two 19-day periods whilst refraining from all other oral hygiene procedures. At days 8, 15 and 19 of the trial, Corsodyl was significantly more effective at inhibiting both plaque and gingivitis. The findings of this study would suggest that the Veadent mouthrinse would at most only have a limited rôle as an inhibitor of plaque and gingivitis.

Chemotherapeutic agents for controlling plaque and gingivitis

There has been a vigorous search for many years for chemical agents that could supplement or even supplant patient-dependent mechanical plaque control and thus reduce or prevent oral disease. 5 categories of agents or approaches have been considered: (1) broad spectrum antiseptics, (2) antibiotics aimed at specific bacteria, (3) single or combinations of enzymes that could modify plaque structure or activity, (4) non-enzymatic dispersing or modifying agents and (5) agents that could affect bacterial attachment. The success of these approaches can be evaluated clinically by the use of standard scoring methods for measuring plaque and gingivitis and their safety established by soft tissue and microbiologic examination. Antiseptic agents have received the bulk of the attention over the years. At present, only 2 antiseptics, the bis-biguanide, chlorhexidine gluconate (Peridex) and a combination of phenol related essential oils (Listerine), have developed sufficient supporting data in 6-month (or longer) studies to gain the approval of the Council On Dental Therapeutics of the American Dental Association. On the basis of short-term studies, cetylpyridinium chloride, zinc and copper salts, sanguinarine and octenidine warrant continued study as does stannous fluoride at an appropriate concentration. On the basis of current research, a new generation of more specific antibacterial agents that interfere with attachment to pellicle can be developed. It is hard to predict, however, that they will affect gingivitis, at least until there is more information on what specific organisms should be targeted.

Six-month effects of a sanguinarine dentifrice on plaque and gingivitis

A six-month, double-blind clinical trial was conducted to determine the effectiveness of a sanguinarine-containing dentifrice in reducing plaque and gingival inflammation. One hundred twenty adult volunteers were randomly assigned to a control or experimental group. The test dentifrice contained 750 mcg/g of sanguinaria extract. A dentifrice of similar composition without sanguinarine was used as the placebo. Plaque and gingival inflammation scores were recorded for four surfaces on each of 12 index teeth at baseline, one-, three, and six-months. Matched pair t-test analyses showed no significant differences between experimental and control groups for mean six-month changes in plaque and gingival inflammation scores in analyses using all 48 sites per subject or in analyses of only the 24 interproximal sites. No long-term reduction was demonstrated in plaque or gingival inflammation with the use of a sanguinarine-containing dentifrice.

Photographic assessment of the antiplaque properties of sanguinarine and chlorhexidine

The purpose of this study was to assess the effect of rinsing and topical application of sanguinarine on labial surface plaque accumulation, compared with topically applied water, and compared with rinsing with chlorhexidine, while refraining from all oral hygiene measures for 5 days. Color photographs of the disclosed plaque were taken at the end of each phase of treatment and blindly traced using an Apple II micro-computer graphic tablet digitizer. The plaque score for each tooth was calculated by dividing the computer reading of the labial plaque surface area by the total labial surface area of the tooth. Topically applied sanguinarine showed better plaque reduction than mouthrinsing with sanguinarine. There was a significant reduction in plaque accumulation after rinsing with chlorhexidine compared with topically applied sanguinarine, water, and mouthrinsing with sanguinarine. The results of this study indicate that chlorhexidine is a more superior antiplaque agent than sanguinarine. The use of an Apple II micro-computer graphic tablet digitizer provided a valuable method for accurate plaque assessments.

Periodic subgingival antimicrobial irrigation of periodontal pockets (I). Clinical observations

The present investigation was undertaken to study the clinical effect of professionally performed periodic subgingival irrigation per se and as an adjunct to scaling and root planing. 10 patients suffering from moderate-severe periodontal disease participated in the study. Following an initial 3-month period of supervised supragingival plaque control, a total of 102 periodontal sites with probing pocket depth greater than or equal to 6 mm and "bleeding on probing" were selected and subjected to a Baseline examination comprising assessments of oral hygiene and gingival conditions, probing depths and probing attachment levels. The pockets in the various jaw quadrants were randomly assigned to one of the following treatment groups: (1) periodic subgingival irrigation with hydrogen peroxide, (2) periodic subgingival irrigation with chlorhexidine, (3) periodic subgingival irrigation with saline and (4) no subgingival treatment. During the first part of the study (baseline-32 weeks), no mechanical debridement of the subgingival area was performed. The irrigation treatment was carried out by the operator 3 times per week during weeks 1 + 2 and 5 + 6 of the trial. In the 2nd part of the trial (32-52 weeks), the sites were subjected to scaling and root planing combined with professional irrigation during weeks 32-38. The previously non-irrigated control sites were not subjected to adjunctive irrigation when mechanically debrided. During the entire study, the patients were recalled for professional tooth cleaning once every 4 weeks. Re-examinations were carried out at 4, 6, 32, 40 and 52 weeks. The results revealed that repeated professional irrigation of unscaled periodontal pockets with chlorhexidine or hydrogen peroxide resulted in a temporarily reduced frequency of bleeding sites, but not in any clinically significant changes in probing assessments. A similar improvement of bleeding scores was observed in the saline-irrigated control group. Scaling and root planing, in combination with an optimal supragingival plaque control, resulted in a marked resolution of the clinical symptoms of periodontal disease. Adjunctive irrigation with chlorhexidine or hydrogen peroxide did not improve the healing result above and beyond that obtained after mechanical debridement alone or in combination with saline irrigation. Hence, the study failed to demonstrate that professionally performed periodic subgingival irrigation with chlorhexidine or hydrogen peroxide, used alone or in combination with thorough mechanical debridement, has a significant therapeutic effect.