The effects of a 0.12% chlorhexidine-digluconate-containing mouthrinse versus a placebo on plaque and gingival inflammation over a 3-month period

Abstract Several previous studies have evaluated the effects of 0.12% chlorhexidine digluconate (ChD) mouthrinses on plaque and gingival inflammation. However, previously, none have been based in general dental practices. The aim of this study was to evaluate the potential to conduct controlled periodontal clinical trials in co-operation with general dental practitioners (gdps). The project took place in 5 general dental practices in the South of England. 121 healthy subjects (24 at 4 sites and 25 at the 5th). aged 18-65 years, mean 35 ± 12) years participated in a double-blind, randomised study during which they received full mouth assessments for plaque and gingival bleeding at baseline, 6 and 12 weeks. 60 subjects were randomly asigned to use the 0.12% ChD mouth wash and 6i the placebo. The assessments were carried out by 5 gpds, who had previously achieved inter-examiner κ scores of 0.78–0.85 (mean 0.81) for the plaque index (PlI), and of 0.73–0.94 (mean 0.87) for a modified gingival index (mGI), and who maintained κ scores of 0.51–0.90 for PII and of 0.73–1.00 for mGI during the 12 months required to complete the study. 98 subjects (48 ChD and 50 placebo) completed the study. Even though the baseline levels of plaque and gingivitis were low, by week 12, mean whole mouth piaque score of the ChD mouthwash users had fallen from 1.33 at baseline to 0.96 and was significantly lower (p < 0.001) than for the placebo users, 1.31 at baseline to 1.13. Whole-mouth gingival bleeding score fell from 0.56 to 0.42 in the ChD mouthwash group but was unchanged (0.54–0.55) in the placebo group. A subsidiary data analysis which considered the effects at sites indicated that within these overall differences, the ChD users experienced almost 2× the reduction from plaque score 2 at baseline at proximal molar sites over a 12-week period (50.6% ChD versus 27.6% placebo). It was concluded that 0.12% ChD mouthwash reduced plaque accumulation fay 28% and gingival inflammation by 25% over a 12–week period, that it is feasible for a group of gdps to maintain high levels of inter–examiner consistency in the use of PlI and mGI, that it is also feasible to carry out such a multicentre study in general dental practice, and that the use of mean mouth scores per subject to analyse the effects of mouthrinses may well mask variations in response throughout the mouth.     

Measurement of γ-enolase release, a new method for selective quantification of neurotoxicity independently from glial lysis

We have developed a sensitive enzymatic-immunoassay to quantify the level of gamma-enolase (a specific neuronal enzyme) which is released from cultured cells after exposure to various toxins. We show that this method can estimate selectively neuronal cell death without significantly interfering with glial cell death. Indeed, no gamma-enolase is released when glial cells are killed with free-radical producing agents. Experiments comparing the levels of neuronal cell death induced by NMDA or free-radical producing drugs, performed either by measuring gamma-enolase release or using the classical fluorescein diacetate method, yielded similar results. In addition to selectively follow neuronal death in a mixed population of neurons and glial cells, this method provides a way of determining the cell death kinetics from a single culture dish, since enolase can be measured on small samples taken from the culture medium. Finally, we propose these two methods as being complementary and useful neuronal and other cellular death indexes and also to understand the complex problem of glial influence on neuronal survival or death.     

Chlorhexidine compared with other locally delivered antimicrobials

Based on the association of bacterial plaque with the initiation of chronic gingivitis and progression of chronic periodontitis, chemical antiplaque agents have been employed both in prevention of periodontal disease and its treatment. In supragingival plaque control regimens, chlorhexidine has not been superceded as a chemical anti-plaque agent, although other compounds have been shown to be useful. The local side-effects of chlorhexidine and other cationic antiseptics, however, limit their long-term use for prevention. Extrinsic tooth staining in particular remains the greatest problem. Short-term anti-plaque uses for chlorhexidine include as an adjunct to mechanical cleaning in the initial oral hygiene phase of treatment, in situations where mechanical oral hygiene is difficult, including postsurgery, intermaxillary fixation, fixed orthodontic therapy, physically and mentally handicapped individuals, systemic diseases with oral manifestations such as leukaemia. More recent interest in chlorhexidine has resulted from the delivery of compounds subgingivally in the treatment of chronic periodontitis. Such methods have extended the use of chlorhexidine into areas inaccessible to the action of antimicrobial drugs delivered locally by conventional means, such as tooth brushing or mouth rinsing. Available evidence suggests that chlorhexidine may not be as effective as some antimicrobial drugs whose activity is more specific for those organisms considered particularly pathogenic to the periodontal tissues.     

Comparison of 2 chlorhexidine mouthwashes on plaque regrowth in vivo and dietary staining in vitro

Abstract Until recently, the few available chlorhexidine mouthrinse products have been 0.2% formulations. However, concentrations of 0.12% chlorhexidine appear as effective as 0.2%, if the volume of the rinse is increased to 15 ml. Since the mere incorporation of chlorhexidine in a formulation does not guarentee availability of the antiseptic, it would seem reasonable to evaluate or compare all products. This is particularly the case when other ingredients, such as fluoride are added. The 1st study compared the effect of a 0.12% chlorhexidine rinse with a 0.12% chlorhexidine/0.022% sodium fluoride rinse for effects on plaque re-growth. The study was a 7-day, blind, randomised, 2-cell cross-over design with a baseline control run in period, in which 18 subjects participated. Both chlorhexidine products significantly reduced plaque compared to control but the chlorhexidine fluoride rinse was less effective than the chlorhexidine only rinse. The 2nd study assessed the propensity of the chlorhexidine rinses to induce dietary staining in vitro. For the chlorhexidine fluoride rinse, this was less than the other 0.12% rinse and a commonly used 0.2% product. The data in vivo and in vitro suggest reduced chlorhexidine availability from the chlorhexidine fluoride product which appears to cause some loss of efficacy.     

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

Abstract. 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 2× daily CHX rinses throughout the 12-week observation interval. Recordings of oral hygiene (PlI), 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 PlI 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 rôle in the management of adult periodontitis.     

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

Abstract. 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^®). Parmacokinetics 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.     

Na+/H+ exchange regulates intracellular pH of rat gastric surface cells in vivo

Intracellular pH (pH_i) and viability of gastric surface cells of the rat stomach in response to luminal acidification, and the role of Na⁺/H⁺ exchange in maintaining pH_i homeostasis were studied in vivo using a fluorescent microscopic technique. pH_i was measured during superfusion with buffers of pH 1.2–7.4. When the pH of the superfusate was 7.4, baseline pH_i was unchanged. Superfusion with pH 3 buffer rapidly decreased pH_i to 6.7, with subsequent recovery to baseline pH_i within 15 min despite continuing acid exposure. Superfusion with buffers of pH 1.7 and 1.2 decreased pH_i continuously to below 6.2 with no recovery observed. Despite the relentless decline in pH_i during superfusion with pH-1.2 and –1.7 solutions, over 75% of the surface cells were still viable, as measured by exclusion of the vital dye propidium iodide. We then examined the role of Na⁺/H⁺ exchange in the regulation of pH_i. Superfusion with amiloride did not affect recovery of pH_i from intracellular acidification induced by a NH₄Cl prepulse. Exposure to the potent, lipophilic Na⁺/H⁺ exchange inhibitor 5-(N,N-hexaniethylene)-amiloride (HMA), either in the superfusate or by close arterial perfusion, decreased baseline pH_i from 7.1 to 6.8. Close arterial perfusion of HMA additionally attenuated the recovery of pH_i to baseline during superfusion with pH 3 buffer. We conclude that luminal protons permeate into the cytoplasm of gastric surface cells, where they are eliminated by an Na⁺/H⁺ exchanger, most probably localized to the basolateral membrane.     

An in vitro and in vivo study of the effect of incorporation of chlorhexidine into autopolymerizing acrylic resin plates upon the growth of Candida albicans

Chlorhexidine acetate was incorporated into autopolymerizing acrylic resin and, after studying its ability to diffuse out in vitro, an investigation was made into the potential of the mixture to treat palatal candidosis in the rat. Chlorhexidine was found to diffuse out of acrylic in fungicidal concentrations for up to three weeks when mixed with the acrylic powder in the proportion of 7.5% (w/w). At this concentration it was found that palatal candidosis as produced by the technique of Shakir et al. was cured or prevented. However, rats fitted with chlorhexidine supplemented plates were found not to take sufficient food during the experimental period to maintain their body weight.     

Antimicrobial mesh versus vaginal wall sling: a comparative outcomes analysis

PURPOSE: We prospectively compared transvaginal antimicrobial mesh (MycroMesh*) and anterior vaginal wall slings using an outcomes analysis. MATERIALS AND METHODS: Between August 1997 and November 1998 we implanted transvaginal slings in 40 consecutive women randomized to a synthetic mesh (20) or vaginal wall (20) group. All patients had documented stress urinary incontinence on preoperative urodynamics. We prospectively compared postoperative outcomes data obtained from pelvic examinations, cough stress test, cotton swab test and validated patient questionnaires using a visual analog scale. RESULTS: Complete followup was available in all patients. Mean followup was 22 months (range 12 to 27). Stress incontinence was cured in 95% of the mesh and 70% of the vaginal wall group, and pelvic prolapse was cured in 100% and 95%, respectively. Transient de novo urge incontinence was noted in 12.5% of the mesh and 14.3% of the vaginal wall group. Mean postoperative cotton swab angle during Valsalva's maneuver was 20 and 45 degrees for the mesh and vaginal wall groups, respectively. The incidence of urinary retention and tissue erosion was 0% for both groups. The satisfaction rate was 100% and 80% for the mesh and vaginal wall groups, respectively. CONCLUSIONS: The antimicrobial MycroMesh sling was superior to the vaginal wall sling for correction of stress incontinence and pelvic prolapse with comparatively low morbidity.