Saltatory Conduction along Myelinated Axons Involves a Periaxonal Nanocircuit.

The propagation of electrical impulses along axons is highly accelerated by the myelin sheath and produces saltating or "jumping" action potentials across internodes, from one node of Ranvier to the next. The underlying electrical circuit, as well as the existence and role of submyelin conduction in saltatory conduction remain, however, elusive. Here, we made patch-clamp and high-speed voltage-calibrated optical recordings of potentials across the nodal and internodal axolemma of myelinated neocortical pyramidal axons combined with electron microscopy and experimentally constrained cable modeling. Our results reveal a nanoscale yet conductive periaxonal space, incompletely sealed at the paranodes, which separates the potentials across the low-capacitance myelin sheath and internodal axolemma. The emerging double-cable model reproduces the recorded evolution of voltage waveforms across nodes and internodes, including rapid nodal potentials traveling in advance of attenuated waves in the internodal axolemma, revealing a mechanism for saltation across time and space.

Corrigendum: Rapid Eye Movements in Sleep Furnish a Unique Probe Into Consciousness.

[This corrects the article DOI: 10.3389/fpsyg.2018.02087.].

Rapid Eye Movements in Sleep Furnish a Unique Probe Into Consciousness.

The neural correlates of rapid eye movements (REMs) in sleep are extraordinarily robust; including REM-locked multisensory-motor integration and accompanying activation in the retrosplenial cortex, the supplementary eye field and areas encompassing cholinergic basal nucleus (Hong et al., 2009). The phenomenology of REMs speaks to the notion that perceptual experience in both sleep and wakefulness is a constructive process - in which we generate predictions of sensory inputs and then test those predictions through actively sampling the sensorium with eye movements. On this view, REMs during sleep may index an internalized active sampling or 'scanning' of self-generated visual constructs that are released from the constraints of visual input. If this view is correct, it renders REMs an ideal probe to study consciousness as "an exclusively internal affair" (Metzinger, 2009). In other words, REMs offer a probe of active inference - in the sense of predictive coding - when the brain is isolated from the sensorium in virtue of the natural blockade of sensory afferents during REM sleep. Crucially, REMs are temporally precise events that enable powerful inferences based on time series analyses. As a natural, task-free probe, (REMs) could be used in non-compliant subjects, including infants and animals. In short, REMs constitute a promising probe to study the ontogenetic and phylogenetic development of consciousness and perhaps the psychopathology of schizophrenia and autism, which have been considered in terms of aberrant predictive coding.

Virtual reality and consciousness inference in dreaming.

This article explores the notion that the brain is genetically endowed with an innate virtual reality generator that - through experience-dependent plasticity - becomes a generative or predictive model of the world. This model, which is most clearly revealed in rapid eye movement (REM) sleep dreaming, may provide the theater for conscious experience. Functional neuroimaging evidence for brain activations that are time-locked to rapid eye movements (REMs) endorses the view that waking consciousness emerges from REM sleep - and dreaming lays the foundations for waking perception. In this view, the brain is equipped with a virtual model of the world that generates predictions of its sensations. This model is continually updated and entrained by sensory prediction errors in wakefulness to ensure veridical perception, but not in dreaming. In contrast, dreaming plays an essential role in maintaining and enhancing the capacity to model the world by minimizing model complexity and thereby maximizing both statistical and thermodynamic efficiency. This perspective suggests that consciousness corresponds to the embodied process of inference, realized through the generation of virtual realities (in both sleep and wakefulness). In short, our premise or hypothesis is that the waking brain engages with the world to predict the causes of sensations, while in sleep the brain's generative model is actively refined so that it generates more efficient predictions during waking. We review the evidence in support of this hypothesis - evidence that grounds consciousness in biophysical computations whose neuronal and neurochemical infrastructure has been disclosed by sleep research.

Arrhythmias in structural heart disease.

The presence of structural heart disease is often associated with the development of electrical abnormalities of the heart, manifesting as atrial and ventricular arrhythmias. These can occur in those with ischemic and nonischemic cardiomyopathies, congenital heart disease, and various acquired and intrinsic structural abnormalities of the myocardium. Treatment of these arrhythmias generally involves treatment of the underlying disorder first, if possible, such as with surgical or catheter-based intervention. Other therapies, including medical therapy with beta-blockers and anti-arrhythmic agents, pacemakers and implantable cardioverter-defibrillators (ICDs), and ablation may be offered both as prophylactic therapy or if arrhythmias have developed. In some instances, therapy is undertaken regardless of whether there are symptoms. ICDs provide support for those patients at risk for malignant, life-threatening arrhythmias, but appropriate patient and device selection are vital to improve mortality and to limit adverse events.

Epidemiology and potential risk factors of drug-related problems in Hong Kong paediatric wards.

AIMS: A drug-related problem (DRP) is 'an event or circumstance involving drug therapy that actually or potentially interferes with the desired health outcome'. The extent and characteristics of DRPs in children in Hong Kong are unknown. The aim of this study was to determine the epidemiology of and identify riskf actors for DRPs in hospitalized children in Hong Kong. METHODS: This was a prospective cohort study in children aged 0­18 years who were admitted to a medical ward, paediatric intensive care unit or neonatal intensive care unit of seven Hong Kong hospitals, during a 3 month period. Patients' charts, medical records and laboratory data were reviewed daily to identify DRPs; their preventability and severity were assessed. Logistic regression was used to analyse potential risk factors associated with the incidence of DRPs. RESULTS: Three hundred and twenty-nine children (median age, 2 years; interquartile range, 0 months to 9 years) were included. In total, 82 DRPs were experienced by 69 patients. The overall incidence of DRPs was 21.0% (95% confidence interval, 16.7­25.8%). The incidence was higher in neonatal and paediatric intensive care units than medical wards. Dosing problems were the most frequently reported DRPs (n = 35; 42.7%), followed by drug choice problems (n = 19; 23.2%) and adverse drug reactions (n = 11; 13.4%). Sixty-seven (81.7%) DRP cases were assessed as preventable, 42 (51.2%) as minor and 40 (48.8%) as moderate. The number of prescribed drugs and 'certain infectious and parasitic diseases' were potential risk factors for occurrence of DRPs. CONCLUSIONS: Drug-related problems were common in hospitalized children in this study in Hong Kong; the most frequent were dosing and drug choice problems, and the majority of them were preventable. Polypharmacy and 'certain infectious and parasitic diseases' were potential risk factors.

Application of radio-frequency identification in perioperative care.

Every perioperative department could benefit from having an information system that facilitates managerial function and improves efficiency in the OR. The Patient Advancement Monitoring System-Surgical implemented in a hospital in Taipei, Taiwan, is one such a system that uses radio-frequency identification technology for tracking perioperative care of patients along workflow checkpoints. This web-based medical information system can facilitate care provided throughout perioperative services by providing instant patient information to staff members in cross-functional health care teams. Manpower is not wasted on duplicating data entry because the surgical progression is displayed in real time. Satisfaction with the system has been high for both nurses and administrators.

RFID-initiated workflow control to facilitate patient safety and utilization efficiency in operation theater.

OBJECTIVE: To control the workflow for surgical patients, we in-cooperate radio-frequency identification (RFID) technology to develop a Patient Advancement Monitoring System (PAMS) in operation theater. METHODS: The web-based PAMS is designed to monitor the whole workflow for the handling of surgical patients. The system integrates multiple data entry ports Across the multi-functional surgical teams. Data are entered into the system through RFID, bar code, palm digital assistance (PDA), ultra-mobile personal computer (UMPC), or traditional keyboard at designated checkpoints. Active radio-frequency identification (RFID) tag can initiate data demonstration on the computer screens upon a patient's arrival at any particular checkpoint along the advancement pathway. RESULTS: The PAMS can manage the progress of operations, patient localization, identity verification, and peri-operative care. The workflow monitoring provides caregivers' instant information sharing to enhance management efficiency. CONCLUSION: RFID-initiate surgical workflow control is valuable to meet the safety, quality, efficiency requirements in operation theater.

Comparative antiplaque and antigingivitis effectiveness of a chlorhexidine and an essential oil mouthrinse: 6-month clinical trial.

OBJECTIVES: The objective of this study was to compare the antiplaque and antigingivitis effectiveness and the side-effect profiles of an essential oil-containing mouthrinse and a chlorhexidine-containing mouthrinse. MATERIAL AND METHODS: One hundred and eight qualifying subjects, aged 20-57 years, were randomized into three groups: essential oil mouthrinse (ListerineAntiseptic); 0.12% chlorhexidine mouthrinse (Peridex); or 5% hydroalcohol negative control. At baseline, subjects received a complete oral soft tissue examination and scoring of the Loe-Silness gingival index (GI), Quigley-Hein plaque index (PI), Volpe-Manhold calculus index (CI), and Lobene extrinsic tooth stain index (SI). Following a complete dental prophylaxis, subjects started rinsing twice daily with their respective mouthrinse as an adjunct to their usual mechanical oral hygiene procedures. One of the rinses on each weekday was supervised. Subjects were reexamined at 3 and 6 months. The treatment groups were compared with respect to baseline demographic and clinical variables. The primary efficacy variables were GI and PI. Intergroup differences for all clinical variables were tested at 3 and 6 months using appropriate statistical procedures. RESULTS: All of the 108 randomized subjects were evaluable at 3 months, and 107 subjects were evaluable at 6 months. There were no statistically significant differences among the three groups at baseline, with the exception that the control group PI was significantly lower than that of the essential oil group (p<0.05) and the chlorhexidine group (p<0.001), and the essential oil mouthrinse group had a significantly greater number of subjects than the control group with body region SI scores > or =1.0 (p=0.021). At 6 months, the essential oil and chlorhexidine mouthrinses produced statistically significant (p<0.001) GI reductions of 14.0% and 18.2%, respectively, and statistically significant (p<0.001) PI reductions of 18.8% and 21.6%, respectively, compared with the control and were not statistically significantly different from each other with respect to plaque and gingivitis reduction. The chlorhexidine mouthrinse group had significantly more calculus and extrinsic tooth stain than either the essential oil mouthrinse group or the control group. CONCLUSION: This 6-month controlled clinical study demonstrated that the essential oil mouthrinse and the chlorhexidine mouthrinse had comparable antiplaque and antigingivitis activity. Insofar as side effects associated with the chlorhexidine mouthrinse may limit patient compliance, it is suggested that each product can have a distinct role in the management of patients with periodontal diseases.

Adjunctive benefit of an essential oil-containing mouthrinse in reducing plaque and gingivitis in patients who brush and floss regularly: a six-month study.

BACKGROUND: Mechanical methods of oral hygiene can be complemented by the use of chemotherapeutic mouthrinses. The authors sought to quantify the additional benefit provided by an essential oil-, or EO-, containing mouthrinse in reducing plaque and gingivitis in patients who brush and floss regularly. METHODS: The authors randomly assigned patients with gingivitis to one of three treatment groups: brushing and rinsing with a control mouthrinse, or BC; brushing, flossing and rinsing with a control mouthrinse, or BFC; or brushing, flossing and rinsing with an EO-containing mouthrinse, or BFEO. Patients received a dental prophylaxis at baseline, and the authors followed them for six months. RESULTS: Of 246 enrolled subjects enrolled in the study, 237 subjects were evaluable at the study's conclusion. After six months, the subjects using the BFEO regimen had statistically and clinically significant lower mean Modified Gingival Index, or MGI, scores and Plaque Index, or PI, scores than did subjects in the BC group (29.9 percent and 56.3 percent, respectively; P < .001). Subjects in the BFC group had statistically significantly lower mean MGI and PI scores than did subjects in the BC group (11.2 percent and 9.3 percent, respectively; P < .001). Subjects in the BFEO group exhibited statistically and clinically significantly lower mean scores for MGI and PI than did subjects in the BFC group (21 percent and 51.9 percent, respectively; P < .001). CONCLUSIONS: This study confirms that for patients with gingivitis who brush and floss routinely, the adjunctive use of an EO-containing mouthrinse provides a clinically significant and meaningful additional benefit in reducing plaque and gingivitis. CLINICAL IMPLICATIONS: An EO-containing mouthrinse is an effective adjunct to regular brushing and flossing. Therefore, the BFEO regimen can be beneficial for patients with gingival inflammation.

Transcoronary implantation of bone marrow stromal cells ameliorates cardiac function after myocardial infarction.

OBJECTIVES: Bone marrow stromal cells are capable of differentiating into cardiomyogenic cells. We tested the hypothesis that transcoronary implantation of bone marrow stromal cells may regenerate infarcted myocardium and reduce cardiac dysfunction. METHODS: Isolated bone marrow stromal cells from the isogenic donor rats were transfected with LacZ reporter gene for cell labeling. To induce cardiomyogenic differentiation, the bone marrow stromal cells were treated with 5-azacytidine before implantation. Two weeks after left coronary ligation, these cells (1 x 10(6) in 150 microL) were infused into the briefly distally occluded ascending aorta of the recipient rats (n = 15) to simulate direct coronary infusion clinically. Control animals were infused with cell-free medium (n = 14). Cardiac function was evaluated by echocardiography at preimplantation and 4 and 8 weeks postimplantation. The hearts were then immunohistochemically studied to identify phenotypic changes of implanted bone marrow stromal cells. RESULTS: Immediately after cell infusion, the bone marrow stromal cells were trapped within coronary vessels in both infarcted and noninfarcted areas. However, after 8 weeks, most of the cells were identified in the scar and periscar tissue, expressing sarcomeric myosin heavy chain and cardiomyocyte-specific protein troponin I-C. Some bone marrow stromal cells were found to be connected to the adjacent host cardiomyocytes with gap junction. Two-way repeated-measures analysis of variance revealed significant improvement in fractional shortening and end-diastolic and end-systolic diameter of the left ventricle (P =.0465,.002,.0004, respectively) in the bone marrow stromal cell group. CONCLUSIONS: Although bone marrow stromal cells had been reported to improve cardiac function when injected directly into the myocardial scar, this study demonstrated for the first time that bone marrow stromal cells can be delivered via the coronary artery, as they are capable of targeted migration and differentiation into cardiomyocytes in the scar tissue to improve cardiac function.

Antiplaque and antigingivitis effectiveness of a hexetidine mouthwash.

OBJECTIVE: To assess the antiplaque/antigingivitis efficacy of a hexetidine-containing mouthwash. METHODS: This examiner-blind, parallel group, controlled clinical study examined the effectiveness of a hexetidine (0.1%) mouthwash both in inhibiting the development of supragingival plaque and in reducing gingivitis. One hundred and thirty-four adult subjects completed the 2-week experimental gingivitis model study. Following baseline examinations, which included plaque index, modified gingival index and gingival bleeding index, subjects received a full dental prophylaxis. Subjects were randomly assigned to one of three mouthwashes (hexetidine 0.1%, chlorhexidine 0.12% (positive control) or a 5% hydroalcohol negative control) and commenced three times daily supervised rinsing as their sole method of oral hygiene. All indices were rescored after 2 weeks. RESULTS: Compared to the negative control group, the hexetidine group demonstrated a statistically significant inhibition and reduction of supragingival plaque and gingival inflammation with reductions of 6.3%, 33.5% and 56% for gingivitis, plaque and gingival bleeding, respectively. The results of the chlorhexidine group were used to validate the study. CONCLUSION: The study confirms the efficacy of a hexetidine rinse in reducing supragingival plaque and gingival inflammation.

The efficacy of an essential oil antiseptic mouthrinse vs. dental floss in controlling interproximal gingivitis: a comparative study.

BACKGROUND: The use of dental floss has long been considered to be effective in controlling interproximal plaque and gingivitis. The authors compared this method with that of use of a mouthrinse. METHODS: Subjects with mild-to-moderate gingivitis enrolled in a long-term, six-month study. They received a dental prophylaxis and were randomized into one of the three following treatment groups: brushing and rinsing with an essential oil-containing mouthrinse (the BEO group), brushing and flossing (the BF group) and brushing and rinsing with a control rinse (the B group). RESULTS: A total of 326 subjects were evaluated. The BEO and BF had significantly lower (P < .001) mean interproximal Modified Gingival Index, or MGI, scores than did the B group at six months. The BEO group had lower mean interproximal Plaque Index, or PI, scores than the other two groups at both three and six months. The BF group's mean PI score was significantly lower than the B group's mean score at six months only. The magnitude of reductions for the BEO and the BF groups (vs. the B group) in MGI were 11.1 percent and 4.3 percent and for PI were 20.0 percent and 3.4 percent, respectively. CONCLUSIONS: In conjunction with professional care (prophylaxis) and toothbrushing over six months, rinsing twice daily with an essential oil-containing mouthrinse was at least as good as flossing daily in reducing interproximal plaque and gingivitis. Clinical Implications. When weighing recommendations for oral hygiene home care, clinicians should consider that an essential oil-containing mouthrinse may be a useful adjunct in patients with gingival inflammation.

Comparative efficacy of an antiseptic mouthrinse and an antiplaque/antigingivitis dentifrice. A six-month clinical trial.

BACKGROUND: The efficacy of an essential oil-containing antiseptic mouthrinse (Listerine Antiseptic, Pfizer) and an antiplaque/antigingivitis dentifrice (Colgate Total, Colgate-Palmolive) has been demonstrated in numerous double-blind clinical studies. This study was conducted to determine their comparative efficacy. METHODS: Three hundred sixteen subjects with mild-to-moderate gingival inflammation and plaque received a dental prophylaxis and began their randomly assigned brushing and rinsing regimen in an unsupervised setting. Subjects brushed for one minute and rinsed with 20 milliliters for 30 seconds twice daily for six months. The three groups were L (control toothpaste/Listerine rinse), T (Colgate Total toothpaste/control rinse) and P (control toothpaste/control rinse). RESULTS: Subjects in the L and T groups demonstrated statistically significantly lower (P < .001) Modified Gingival Index, or MGI; Bleeding Index, or BI; and Plaque Index, or PI, at both three and six months than subjects in the P group. The magnitude of reduction for the L group was 22.9 percent, 70 percent and 56.1 percent, respectively, and for the T group, 20.8 percent, 58 percent and 22.1 percent, respectively. Subjects in the L group were not different from subjects in the T group in regard to visual signs of gingivitis (MGI), but were more effective (P < .001) than subjects in the T group in experiencing reduced BI and PI. No product-related adverse events were reported. CONCLUSION: Although the Listerine Antiseptic and Colgate Total antiplaque/antigingivitis products produced similar, clinically significant reductions in gingivitis (as measured by MGI and BI), Listerine, when used in conjunction with a fluoride dentifrice and usual oral hygiene, provided a greater benefit in reducing plaque. CLINICAL IMPLICATIONS: When considering an antiplaque/antigingivitis product to recommend to patients, clinicians should consider Listerine Antiseptic, in conjunction with usual oral hygiene, if more rigorous plaque control is desired.

Anticalculus efficacy of an antiseptic mouthrinse containing zinc chloride.

BACKGROUND: The authors undertook a controlled clinical study to determine the efficacy of a tartar-control antiseptic mouthrinse in inhibiting the development of supragingival dental calculus. METHODS: After undergoing a dental prophylaxis, 334 subjects with a moderate rate of calculus formation were stratified and randomly assigned to one of three groups: positive control (using a tartar-control toothpaste and an antiseptic rinse), negative control (using a regular toothpaste and an antiseptic mouthrinse) or experimental (using a regular dentifrice and a tartar-control mouthrinse). Subjects brushed and rinsed twice daily, unsupervised, for four months. The researchers assessed subjects' calculus levels using the Volpe-Manhold Index, or VMI, after 16 weeks. RESULTS: Using analysis of covariance, the authors found that both the experimental group (which used a tartar-control rinse containing zinc chloride) and the positive control group (which used a tartar-control dentifrice containing pyrophosphate) demonstrated statistically significantly lower VMI scores (P = .001) than the negative control group (which used a regular dentifrice and an antiseptic rinse). Both anticalculus agents provided a clinically relevant 21 percent reduction in calculus formation. CONCLUSION: An antiseptic mouthrinse containing 0.09 percent zinc chloride as the anticalculus agent provides a clinically relevant reduction in calculus formation in people with a moderate rate of such formation. CLINICAL IMPLICATIONS: A tartar-control mouthrinse with zinc chloride as the tartar-control ingredient is clinically effective in reducing the formation of calculus.

Effect of an essential oil-containing antiseptic mouthrinse on plaque and salivary Streptococcus mutans levels.

BACKGROUND: Clinical studies in which antimicrobial mouthrinses were shown to have significant antiplaque activity most frequently have used gingivitis as the clinically relevant endpoint. However, there is evidence to suggest that mouthrinses containing active agents effective against Streptococcus mutans, such as chlorhexidine, may also have a role in inhibiting dental caries. This clinical study was conducted to determine the effect of 2x-daily rinsing with an essential oil-containing antiseptic mouthrinse (Listerine Antiseptic) on levels of recoverable S. mutans and total streptococci in supragingival interproximal plaque and in saliva. Additionally, a follow-up in vitro study is reported which determined whether a differential susceptibility to the antiseptic mouthrinse exists among different strains of streptococci. METHOD: Following baseline saliva and plaque sampling for quantification of recoverable S. mutans and total streptococci, 29 qualifying subjects were randomly assigned either the essential oil mouthrinse or a sterile water control. They rinsed with 20 ml for 30s 2 x daily for 11 days and once on the 12th day, in addition to their usual oral hygiene procedures. On day 12, saliva and plaque samples were again collected and microbiological quantification performed. The procedures were repeated with the alternate rinse after a 1-week washout period. RESULTS: The essential oil mouthrinse produced respective reductions of 69.9% and 75.4% in total recoverable streptococci and in S. mutans in plaque, and corresponding reductions of 50.8% and 39.2% in saliva. The in vitro study revealed that streptococci from the mutans group were more susceptible to the bactericidal activity of the essential oil mouthrinse than streptococci from the mitis group. CONCLUSIONS: As antimicrobial mouthrinses are most frequently recommended to patients whose mechanical oral hygiene procedures are not adequate for the control of supragingival plaque and gingivitis, this study provides an additional rationale for the inclusion of the essential-oil mouthrinse as an adjunct to daily oral hygiene procedures.

Effect of an essential oil-containing dentifrice on dental plaque microbial composition.

PURPOSE: To determine the effect of 6 months use of an essential oil-containing (EO) antiplaque/antigingivitis fluoride dentifrice on the balance of the oral microbial flora and on the emergence of resistant microbial forms by analysis of dental plaque and saliva. MATERIALS AND METHODS: The dentifrice essential oils consisted of a fixed combination of thymol, menthol, methyl salicylate, and eucalyptol. An identical fluoride-containing dentifrice without the essential oils served as the control. A subgroup of 66 subjects from a clinical trial population of 321 was randomly selected for characterization of their dental plaque microflora. Saliva was also cultured to monitor for the emergence of opportunistic pathogens. Supragingival plaque and saliva were harvested at baseline, after which subjects received a dental prophylaxis. Subjects were sampled again after 3 and 6 months of product use prior to clinical examination. Plaque was characterized for microbial content by phase contrast microscopy for recognizable cellular morphotypes and by cultivation on nonselective and selective culture media. Determination of the minimum inhibitory concentrations of the test agent against selected Actinomyces and Veillonella isolated bacterial species was conducted at all time points to monitor for the potential development of bacterial resistance. RESULTS: There were no statistically significant differences between the microbial flora obtained from subjects using the essential oil-containing dentifrice and the vehicle control for all parameters and time periods except for the percentage of spirochetes at 6 months and for percentage of "other" microorganisms at 3 months. The EO group exhibited a lower adjusted mean for both parameters. Additionally, there was no evidence of the development of bacterial resistance to the antimicrobial activity of the essential oils or the emergence of opportunistic pathogens.

In vivo antimicrobial activity of an essential oil-containing mouthrinse on interproximal plaque bacteria.

This study determined the in vivo interproximal bactericidal efficacy of an essential oil-containing antiseptic mouthrinse (Listerine Antiseptic) following toothbrushing. Thirty-four generally healthy adults, aged 23-64 years, completed this evaluator-blind, randomized, controlled, crossover designed study. Subjects rinsed for 30 seconds with 20 ml of either the essential oil rinse or a negative control rinse. Five minutes later, interproximal plaque was collected using paper points, and recoverable bacterial counts were quantified using both end point dilution and spectrophotometric methods. The results from the end point dilution demonstrated a statistically significant (p < 0.001) 43.8% reduction in recoverable plaque bacteria from interproximal spaces following rinsing with the essential oil mouthrinse. This study suggests that the clinical effectiveness of the essential oil mouthrinse against plaque and gingivitis may be attributable to the rapid kill and plaque permeabilizing properties of the formulation.

Effect of an antiseptic mouthrinse on salivary microbiota.

PURPOSE: To evaluate the effect of rinsing with original formulation Listerine Antiseptic (LA) on the level of viable salivary bacteria for periods up to 1 hour. MATERIALS AND METHODS: In this double-blind, controlled, cross-over study, unstimulated saliva was collected from 25 subjects, serially diluted, and cultured on selective and non-selective media under aerobic and anaerobic conditions. Streptococci, Veillonella sp., and total aerobic and anaerobic flora were enumerated just prior to and 2, 15, 30, and 60 minutes after rinsing for 30 seconds with either 20 ml of LA or a 5% hydroalcohol control rinse. RESULTS: After the control rinse, total flora cultivated on MM10 agar exhibited a non-significant (P > 0.05) 10%-20% decrease relative to baseline. In contrast, rinsing with LA resulted in a significant (P < 0.05) 60%-65% decrease from baseline in all four microbial groups at 2 minutes; except in the case of Veillonella, the significant decreases were sustained up to 60 minutes. Total Listerine group aerobic, anaerobic and streptococcal counts were significantly lower than placebo (P < 0.05). The significant reduction in salivary bacterial levels seen in the Listerine group for up to 60 minutes suggests that this antiseptic mouthrinse may have use clinically as a pre-procedural rinse to decrease the level of viable microorganisms in aerosols generated during dental procedures.

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)