Results of a randomised controlled trial between an ORC collagen hemostatic agent and a carrier-bound fibrin sealant.

INTRODUCTION: Despite ongoing optimisation of surgical techniques, hemostasis continues to be a fundamental challenge in many operations today. This randomised controlled trial compared the efficacy of a new hemostatic agent made of oxidised regenerated cellulose and collagen (ORC-Coll) with that of a conventional carrier-bound fibrin sealant (CBFS). METHODS: Hemostasis was investigated representatively in the case of post-thyroidectomy bleeding from the resection surface. To demonstrate that ORC-Coll (mediCipio® A) has at least the same hemostatic efficacy as CBFS (Tachosil®), the volume of drainage fluid at the time of drain removal was used as the primary endpoint in a non-inferiority test with a significance level of 5%. The secondary endpoints included number and size of hemostatic agents required, adhesion of the hemostatic agent to the bleeding surface, intraoperative hemostatic effect, duration of drainage and adverse events during a six-month follow-up period. RESULTS: A total of 150 patients (ORC-Coll: 75; CBFS: 75) were included. After operation, total volume of drainage fluid was 68.20±44.56mL in the ORC group and 68.21±40.20mL in the CBFS group. The non-inferiority of ORC-Coll compared to CBFS with regard to hemostatic efficacy was shown at a significance level of 5%. The results demonstrated effectiveness in achieving hemostasis without adverse events. CONCLUSIONS: ORC-Coll is an effective hemostatic agent and barrier sealant without blood components, which ensures reliable prevention of intra- and postoperative bleeding. With use of the new technique, any risks associated with the use of human blood components are a priori eliminated.

[Influence of nutrition, common autoimmune diseases and smoking on the incidence of foot mycoses]. / Einfluss von Ernährung, autoimmunen Volkskrankheiten und Rauchen auf die Erkrankungshäufigkeit von Fußmykosen.

BACKGROUND: Foot mycoses, including onychomycoses, are worldwide infectious diseases. As part of a regional survey using randomly selected residents of in Mecklenburg-Western Pomerania, we investigated the impact of dietary habits, the presence of most frequent autoimmune diseases and current smoking on fungal skin infections in order to reveal potential new risk factors to elucidate potential preventive interventions. OBJECTIVES: The identification of potential new factors that influence the development of mycosis was performed in order to derive possible preventive measures. METHODS: In the Study of Health in Pomerania (SHIP) in Mecklengburg-Western Pomerania, 2523 inhabitants were examined for mycotic lesions and asked about nutritional habits, the presence of atopic dermatitis, allergic rhinitis, psoriasis and smoking habits. RESULTS: In all, 8% of probands were diagnosed with mycosis, 6.5% onychomycosis, 3.7% tinea pedis and 0.2% tinea corporis. Psoriasis, allergic rhinitis and atopic dermatitis and frequent consumption of cooked potatoes, oatmeal and corn flakes, cereals, pasta and rice were significantly associated with tinea pedis. Onychomycosis was positively associated with consumption of cooked potatoes. Cigarette consumption proved protective for tinea pedis and dermatophyte colonization. CONCLUSIONS: The autoimmune disorders psoriasis and atopic dermatitis and allergic rhinitis seem to predispose to foot mycosis. Recalcitrant mycosis should raise the question of diets high in carbohydrates. Nicotine abuse seems to protect against skin mycosis and colonization.

Long-term outcome of open surgery in CVI patients concerning postoperative complications, perioperative hemodynamics and clinical efficacy, Part II1.

BACKGROUND: Chronic venous disease (CVD) is extremely common worldwide with prevalence increasing with age. It is associated with a reduced quality of life, particularly in relation to pain, physical function and mobility. Symptomatic chronic venous insufficiency (CVI) with venous ulcer at its' endpoint, indicates interventional surgery to cure venous reflux therewith promoting wound healing and preventing recurrence. In this retrospective, single-centre, consecutive case-control study in a single patient population of a university clinic in northern Germany a holistic evaluation of varicose vein surgeries has been undertaken. Part I covered postoperative complications in relation to co-morbidities, co-medication and clinical presentation. Part II of this article presents now the hemodynamic results in relation to the perioperative evolution of CVI specific symptoms. METHODS: Records of n = 429 (467 extremities) patients from 2009-2013 treated with open surgery were analysed with regards to perioperative hemodynamics. Evolution of CVI symptomology was accessed postoperatively with the help of a questionnaire and patient records in the case of complication development. Venous hemodynamics was analysed in the whole patient population and with regards to complication subgroups: no events (NE), neglectable adverse events (NAE) and non-neglectable adverse events (NNAE). RESULTS: Postoperatively, patients' CVI-symptoms like pain (p < 0.001), swelling (p < 0.001) and itching (p = 0.003) significantly improved. The venous refill time and venous pump capacity improved significantly after open vein surgery (p < 0.05). Regardless of the development of postoperative complications there was a significant improvement of venous function at 6 weeks- and one-year postoperative in follow-up (p < 0.05). Symptom regression was strongly correlated with hemodynamic improvement. CONCLUSION: A significant improvement of patients' symptoms was achieved by means of open-surgery, regardless of postoperative complication development. This was in accordance with the improvement of venous hemodynamics. A strong correlation between symptom regression and improvement in venous hemodynamics could be proven.

Rheopheresis as a causal therapy option for systemic scleroderma (SSc).

A complex pathomechanism accounts systemic sclerosis as a form of collagenosis. A triad of vasculopathy, autoinflammation, and dysbalance of the fibroblast function can be seen as cause, as well as symptomatic appearance. Comparative with other collagenoses, e.g. Lupus erythematosus, vasculopathy, instead of autoinflammation, appears to be clinically important in systemic scleroderma. The fact that autoinflammation does not represent the major role in the maintenance of the disease is also evident by the lack of therapeutic effects of classical systemic immunosuppressants. Therapeutic approaches with regard to vasculopathy show better effects. In consideration of therapeutic options, such principles are therefore most important. Apheretic methods filter out plasma proteins in the sense of plasmapheresis. Fibrinogen as a plasma viscosity factor is predominantly targeted and filtered out. In addition other accompanying plasma proteins are also reduced. This occurs on the one hand by dilution effects and on the other by unspecific binding. By this mechanism, acute phase proteins such as the C-reactive protein and various cytokines, especially interleukin-6 are reduced by this method. Looking more closely at these random adjunctive plasma proteins, a possible central role of interleukin-6 in the development and maintenance cascade of systemic scleroderma becomes clear.

Virucide properties of cold atmospheric plasma for future clinical applications.

Cold atmospheric plasma (CAP) has been repeatedly identified to bear powerful microbicidal efficacy on bacteria including multidrug resistant organisms and fungi on non-living surfaces, in biofilms as well as on contaminated and infected tissues. CAP furthermore was found to stimulate wound healing in chronic wounds and exerted anti-neoplastic effects on numerous tumor entities. Thus, CAP represents a promising medical tool for many clinical and therapeutic issues. Studies about CAP effects on virus particles recently were in arrears, but to date increasingly move into the focus of interest. Apparently, CAP treatment is followed by a promising virus inactivation and contributes to tissue regeneration. Here we review the current state of science concerning the so far investigated CAP effects on different virus species and virus-associated disorders. J. Med. Virol. 89:952-959, 2017. © 2017 Wiley Periodicals, Inc.

Antimicrobial efficacy of preoperative skin antisepsis and clonal relationship to postantiseptic skin-and-wound flora in patients undergoing clean orthopedic surgery.

Nosocomial surgical site infections (SSI) are still important complications in surgery. The underlying mechanisms are not fully understood. The aim of this study was to elucidate the possible role of skin flora surviving preoperative antisepsis as a possible cause of SSI. We conducted a two-phase prospective clinical trial in patients undergoing clean orthopedic surgery at a university trauma center in northern Germany. Quantitative swab samples were taken from pre- and postantiseptic skin and, additionally, from the wound base, wound margin, and the suture of 137 patients. Seventy-four patients during phase I and 63 during phase II were investigated. Microbial growth, species spectrum, and antibiotic susceptibility were analyzed. In phase two, the clonal relationship of strains was additionally analyzed. 18.0 % of the swab samples were positive for bacterial growth in the wound base, 24.5 % in the margin, and 27.3 % in the suture. Only 65.5 % of patients showed a 100 % reduction of the skin flora after antisepsis. The microbial spectrum in all postantiseptic samples was dominated by coagulase-negative staphylococci (CoNS). Clonally related staphylococci were detected in ten patients [nine CoNS, one methicillin-susceptible Staphylococcus aureus (MSSA)]. Six of ten patients were suspected of having transmitted identical clones from skin flora into the wound. Ethanol-based antisepsis results in unexpected high levels of skin flora, which can be transmitted into the wound during surgery causing yet unexplained SSI. Keeping with the concept of zero tolerance, further studies are needed in order to understand the origin of this flora to allow further reduction of SSI.

[Infections Associated with Treatment with Hirudo medicinalis - Report of Two Cases and Review of the Literature]. / Infektionen im Zusammenhang mit der Anwendung von Hirudo medicinalis - Zwei Fallberichte und Literaturübersicht.

Medicinal leeches are well-established for promoting venous drainage in transplants/flaps and analgesia in osteoarthritis. Although medicinal leeches are bred and kept under controlled conditions, they are colonised by a genuine species-specific bacterial flora. Therapeutic application of leeches implies skin penetration carrying an a priori risk of infection. We report 2 cases with different indications for medicinal leech therapy. In both cases wound infection occurred in close temporal and spatial correlation or with evidence of a leech-associated germ that could be treated successfully. An unclarified complication rate warrants strict indications for the application of medicinal leeches. Preventive measures are currently tested.

Filtration effects of zebra mussels on pathogens and total bacterial burden in the Odra Lagoon (South Baltic).

As a result of their mode of filter feeding, zebra mussels (Dreissena polymorpha Pall.) have been observed to purify natural water bodies and in vitro. Therefore, the possibility of using zebra mussels for water purification was investigated in a slightly brackish water body of a large lagoon. In this study, water samples were taken above, near and at distance from zebra mussel beds (MB) in the Odra Lagoon in North East Germany. Near typical bacterial species like Aeromonas spp. pathogenic bacteria with potential relation to hospital wastewater pollution (Burkholderia cepacia, Staphylococcus aureus, Weeksella spp.) were detected. There were no correlations found between either total bacteria or pathogens and distance to MB and no antimicrobial effect of the mussels could be deduced. For bioremediation in larger water bodies like lagoons, natural zebra MB do not seem to play a major antimicrobial role and the effect of artificial mussel grids especially against hospital pathogens should be investigated.

Alleviation of chronic venous leg ulcers with a hand-held dielectric barrier discharge plasma generator (PlasmaDerm(®) VU-2010): results of a monocentric, two-armed, open, prospective, randomized and controlled trial (NCT01415622).

BACKGROUND: Cold atmospheric plasma (CAP, i.e. ionized air) is an innovating promising tool in reducing bacteria. OBJECTIVE: We conducted the first clinical trial with the novel PlasmaDerm® VU-2010 device to assess safety and, as secondary endpoints, efficacy and applicability of 45 s/cm(2) cold atmospheric plasma as add-on therapy against chronic venous leg ulcers. METHODS: From April 2011 to April 2012, 14 patients were randomized to receive standardized modern wound care (n = 7) or plasma in addition to standard care (n = 7) 3× per week for 8 weeks. The ulcer size was determined weekly (Visitrak® , photodocumentation). Bacterial load (bacterial swabs, contact agar plates) and pain during and between treatments (visual analogue scales) were assessed. Patients and doctors rated the applicability of plasma (questionnaires). RESULTS: The plasma treatment was safe with 2 SAEs and 77 AEs approximately equally distributed among both groups (P = 0.77 and P = 1.0, Fisher's exact test). Two AEs probably related to plasma. Plasma treatment resulted in a significant reduction in lesional bacterial load (P = 0.04, Wilcoxon signed-rank test). A more than 50% ulcer size reduction was noted in 5/7 and 4/7 patients in the standard and plasma groups, respectively, and a greater size reduction occurred in the plasma group (plasma -5.3 cm(2) , standard: -3.4 cm(2) ) (non-significant, P = 0.42, log-rank test). The only ulcer that closed after 7 weeks received plasma. Patients in the plasma group quoted less pain compared to the control group. The plasma applicability was not rated inferior to standard wound care (P = 0.94, Wilcoxon-Mann-Whitney test). Physicians would recommend (P = 0.06, Wilcoxon-Mann-Whitney test) or repeat (P = 0.08, Wilcoxon-Mann-Whitney test) plasma treatment by trend. CONCLUSION: Cold atmospheric plasma displays favourable antibacterial effects. We demonstrated that plasma treatment with the PlasmaDerm® VU-2010 device is safe and effective in patients with chronic venous leg ulcers. Thus, larger controlled trials and the development of devices with larger application surfaces are warranted.

[Importance of modern treatment procedures for infected and colonized wounds in dermatology]. / Stellenwert moderner physikalischer Behandlungsverfahren bei infizierten und kolonisierten Wunden in der Dermatologie.

In the coming years increasing numbers of patients with chronic ulcers and tumor wounds are to be expected, both of which are typically multifaceted diseases requiring complex and increasingly long-term ambulatory therapy. Therefore, in recent years special medical emphasis has been placed on efficacious therapies with good tolerability and also suitability regarding feasibility for outpatient treatment. Some of these methods, such as cold plasma therapy, extracorporeal shock wave therapy (ESWT), water-filtered infrared therapy (wIRA), electrostimulation (ES) and low level laser therapy (LLLT) have a good chance of success when applied as an adjuvant method in the multimodal treatment concept for patients with recalcitrant wounds. All of these methods have at least indirect antimicrobial properties which can be advantageous in cases of microbial infiltration of wounds. As for all other methods for treating recalcitrant wounds, the promising application of the aforementioned methods requires great expertise in wound healing together with a broad and continuous interdisciplinary diagnostics and therapy (wound center).

[Significance and prevention of post-operative wound complications]. / Bedeutung und Prävention postoperativer Wundkomplikationen.

Although surgical site infections (SSI) in dermatologic operative procedures are extremely rare, it is important to understand risks and etiological factors to initiate risk assessment and specific preventive measures. SSI commonly are associated with a complicated, long-term and expensive outcome. Typical wound pathogens of these infections include a variety of multiresistant organisms along with Staphylococcus aureus, Staphylococcus epidermidis, hemolytic streptococci and the gram-negative bacilli Escherichia coli and Pseudomonas aeruginosa. Effective hygienic measures as part of an adequate quality management system should consider the critical points in the development of SSI, particularly in the setting of an outpatient dermatologic unit, such as preparation of the operative area, preoperative skin antisepsis, hand hygiene, safe and skilled technique by surgeons, and barrier nursing to prevent spread of pathogens. The baseline infection incidence in dermatologic surgery inherently is low; nevertheless significant improvements can be achieved by implementation of risk-adapted infection control measures.

[Microbial stress of skin and wounds in clinical aspects and practice. Between search and destroy and monitor and relax]. / Mikrobielle Belastung von Haut und Wunden in Klinik und Praxis. Zwischen "Search and Destroy" und "Monitor and Relax".

The antibiotic treatment of microbial pathogens of the skin and wounds could so far not fulfil the expectations of an effective and permanent elimination of pathogens so that local treatment with antiseptic agents as a flanking measure to wound cleansing and debridement has become increasingly more established. Because an antiseptic treatment does not actually represent a treatment of infections, the current antimicrobial treatment strategy for infections in skin and wound areas consists of combined antibiotic and flanking antiseptic administration following debridement. However, the combined therapy is not always successful. There is an urgent need for new forms of therapy particularly to combat multiresistant pathogens in biofilms in infections of chronic and other complicated wounds.

Skin decontamination by low-temperature atmospheric pressure plasma jet and dielectric barrier discharge plasma.

BACKGROUND: Over the past few years, plasma medicine has become an important field in medical science. Cold plasma has proven anti-inflammatory, antimicrobial and antineoplastic effects. AIM: To test the decontamination power of two cold plasma sources [low-temperature atmospheric pressure plasma jet (APPJ) and dielectric barrier discharge plasma (DBD)] in vivo on human fingertips. METHODS: After 3, 15, 30, 60, 90, 120, 150, 180, 210 and 240 s of spot treatment with the APPJ and DBD, the log reduction factors (RFs) of physiological (PF) and artificially (AF) contaminated flora (Staphylococcus epidermidis and Micrococcus luteus) were calculated. The bacterial load was determined after counting. Tolerance (paresthesia, pain and heat) was measured using a numerical rating scale. FINDINGS: Both plasma devices led to a significant reduction in PF and AF. The maximum log reduction factors for PF were 1.3 for the DBD at 210 s and 0.8 for the APPJ at 60 s. For AF, the maximum log reduction factors were 1.7 for the DBD at 90 s and 1.4 for the APPJ at 120 s. Treatment with both devices was well tolerated. CONCLUSION: Both the APPJ and DBD were highly effective in eradicating PF and AF from the fingertips of healthy volunteers. No plasma-resistant isolates were observed. Cold plasma appears to have potential for skin disinfection. For hand hygiene purposes, plasma exposure times would need to be reduced significantly by technical means.

Kinetics of physiological skin flora in a suction blister wound model on healthy subjects after treatment with water-filtered infrared-A radiation.

The effect of water-filtered infrared-A radiation (wIRA) on normal skin flora was investigated by generating experimental wounds on the forearms of volunteers utilizing the suction blister technique. Over 7 days, recolonization was monitored parallel to wound healing. Four groups of treatment were compared: no therapy (A), dexpanthenol cream once daily (B), 20 min wIRA irradiation at 30 cm distance (C), and wIRA irradiation for 30 min once daily together with dexpanthenol cream once daily (D). All treatments strongly inhibited the recolonization of the wounds. Whereas dexpanthenol completely suppressed recolonization over the test period, recolonization after wIRA without (C) and in combination with dexpanthenol (D) was suppressed, but started on day 5 with considerably higher amounts after the combination treatment (D). Whereas the consequence without treatment (A) was an increasing amount of physiological skin flora including coagulase-negative staphylococci, all treatments (B-D) led to a reduction in physiological skin flora, including coagulase-negative staphylococci. In healthy volunteers, wIRA alone and in combination with dexpanthenol strongly inhibited bacterial recolonization with physiological skin flora after artificial wound setting using a suction-blister wound model. This could support the beneficial effects of wIRA in the promotion of wound healing.

[Prevention of infections under anesthetic breathing with breathing filters: concerted recommendations of the Deutsche Gesellschaft für Krankenhaushygiene e.V. (DGKH) and the Deutsche Gesellschaft für Anästhesiologie und Intensivmedizin e.V. (DGAI)]. / Infektionsprävention bei der Narkosebeatmung durch Einsatz von Atemsystemfiltern: Gemeinsame Empfehlung der Deutschen Gesellschaft für Krankenhaushygiene e.V. (DGKH) und der Deutschen Gesellschaft für Anästhesiologie und Intensivmedizin e.V. (DGAI).

An interdisciplinary working group from the German Society of Hospital Hygiene (DGKH) and the German Society for Anesthesiology and Intensive Care (DGAI) worked out the following recommendations for infection prevention during anesthesia by using breathing system filters (BSF). The BSF shall be changed after each patient. The filter retention efficiency for airborne particles is recommended to be >99% (II). The retention performance of BSF for liquids is recommended to be at pressures of at least 60 hPa (=60 mbar) or 20 hPa above the selected maximum ventilation pressure in the anesthetic system.The anesthesia breathing system may be used for a period of up to 7 days provided that the functional requirements of the system remain unchanged and the manufacturer states this in the instructions for use. The breathing system and the manual ventilation bag are changed immediately after the respective anesthesia if the following situation has occurred or it is suspected to have occurred: Notifiable infectious disease involving the risk of transmission via the breathing system and the manual bag, e.g. tuberculosis, acute viral hepatitis, measles, influenza virus, infection and/or colonization with a multi-resistant pathogen or upper or lower respiratory tract infections. In case of visible contamination e.g. by blood or in case of defect, it is required that the BSF and also the anesthesia breathing system is changed and the breathing gas conducting parts of the anesthesia ventilator are hygienically reprocessed.Observing of the appropriate hand disinfection is very important. All surfaces of the anesthesia equipment exposed to hand contact must be disinfected after each case.

Bacterial burden of worn therapeutic silver textiles for neurodermitis patients and evaluation of efficacy of washing.

To reduce pruritus and colonization with Staphylococcus aureus, textiles containing silver are increasingly used as therapeutic option for patients with atopic dermatitis (AD). While wearing such textiles, the contained silver is in close contact with the patient's skin. The silver serves two purposes: to reduce bacterial colonization of the skin, and to prevent contamination of the textile with ensuing growth of microorganisms. It is unknown whether the silver impregnation is able to reduce bacterial contamination of the textile during wearing and to prevent bacterial growth within the textile. The aim of this study was to investigate the bacterial contamination in textiles containing silver versus placebo worn by patients with AD and to determine the efficacy of processing worn textiles by manual and machine-based washing. Additionally, the effect of silver textiles on S. aureus and total bacterial counts colonizing the skin of AD patients was analyzed. The reduction factor of silver textile compared to placebo was 0.5 log steps against S. aureus and 0.4 log steps against total bacteria. Silver textiles exhibited significantly less S. aureus as well as total bacterial colonization after 2 days of wearing without washing, as compared with a placebo textile. On placebo textiles 385.6 +/- 63.5 CFU total bacteria and 236.5 +/- 49.9 CFU S. aureus, and on silver textiles 279.9 +/- 78.7 CFU total bacteria and 119.3 +/- 39.4 CFU S. aureus were found on the inner side of the textiles facing the neurodermitis lesions. However, the unexpectedly high residual contamination despite the silver exposure represents a potential risk as recontamination source of S. aureus that could maintain the proinflammatory process in AD. This contamination is nearly completely eliminated by machine-based washing at 60 degrees C using conventional washing powder. AD patients wearing silver textiles should change their used clothes at least daily and wash them in a washing machine at 60 degrees C.

Feasibility and clinical applicability of polihexanide for treatment of second-degree burn wounds.

OBJECTIVES: Due to a partial rejection of mesh split-thickness skin grafts (mesh grafts) after application of povidone-iodine and silver nitrate and due to its better in vitro tolerance, polihexanide was investigated as an alternative and its applicability in the treatment of second-degree burn wounds. METHODS: In 4 patients with poorly healing decubitus ulcers the mesh grafts were each divided into three areas which were pre-treated with either undiluted povidone-iodine solution, 1% silver nitrate solution or 0.04% polihexanide solution. After 7 days of application the wound areas were compared clinically and histologically. Thereafter 14 patients (average extent of burns 28% TBSA) were treated in the same way. RESULTS: Clinically and histologically the mesh grafts treated with polihexanide showed by far the best re-epithelialization compared with the deep tissue necrosis and marked fibrin discharge observed for application of povidone-iodine and silver nitrate. The second-degree burn wounds treated with polihexanide epithelialized without any further débridement after an average of 10 days with remarkable freedom from pain. Compared with silver nitrate treatment, no fibrin film was observed on the wound. CONCLUSION: Polihexanide proved clinically and histologically superior to povidone-iodine and silver nitrate. For the treatment of second-degree burns, which cannot primarily be covered by plastic surgery, polihexanide is suitable because in addition to its antiseptic efficacy it does not inhibit the re-epithelialization process.

Tinea capitis: ringworm of the scalp.

The guideline tinea capitis, as passed by three German medical societies, is presented in the present study.

The peritoneal explant test for evaluating tissue tolerance to mouthrinses.

The tissue cultures of explants of neonatal rat peritoneum have been demonstrated to be a sensitive test for tissue compatibility with wound antiseptics. The present study investigated the suitability of this method to assess the relative toxicity of mouthrinses to tissue. Mouthrinses containing 0.1% chlorhexidine (Chlorhexamed Fluid 0.1%) (A), 0.3% triclosan (Colgate) (B), essential oil in ethanolic solution (Listerine) (C), and amine/stannous fluoride (Meridol) (D) were tested at use concentration and in dilutions of 10, 1, and 0.1% with exposure times of 1, 10, and 30 min, respectively. The mouthrinses (test) and Ringer's solutions (control) were applied to opened rat peritoneum. After thorough irrigation with Ringer's solution, a piece of peritoneum was removed and 1 x 1 mm explants were cut. The explants were cultivated with a bovine serum culture medium in 24-well plates at 37 degrees C in a CO2 incubator (95% air, 5% CO2). After 10 days, the tissue proliferation for the explants was assessed by a stereo microscope at 10x magnification after ethanol fixing and hemalaun staining. With 24 grafts per test, the proliferation rate was calculated relative to a control, which was run for each mouthrinse and concentration/time combination. Data were analyzed using ANOVA (SPSS 11.0) and post-hoc paired t test. Statistical significance of all correlations was tested by setting the significance level at p < 0.05. At most concentrations, D caused significantly less tissue damage than A or B. There was no difference between C and A or C and B at 100%. However, the toxicity of C was significantly less than A or B at 10, 1, and 0.1%. C and D behaved similarly except for the 10% (30 min) and the 1% (10 min) solutions in which C was significantly less toxic. We concluded that the rat peritoneum explant test was demonstrated to be a sensitive test to assess the relative toxicity of mouthrinses to tissue.