Comparison of two mouthrinses in relation to salivary flow and perceived dryness.

OBJECTIVE: To compare measures of dry mouth following extended use of an alcohol-based mouthrinse (LISTERINE Antiseptic [LA]) and a non-alcohol-based mouthrinse (Crest Pro-Health Rinse [CPH]) on healthy adults with "normal" salivary flow. METHODS: This single-site, randomized, observer-blinded, parallel study compared unstimulated whole salivary flow and perceived dryness following daily use at weeks 4 and 12 versus baseline. Noninferiority, between-treatment flow comparisons (0.15 mL/min margin), and between-treatment comparisons of the mean Bluestone Mouthfeel Questionnaire (BMQ) visual analog scale scores were made using analysis of covariance. RESULTS: Measures of dry mouth were comparable between mouthrinses, as demonstrated by both noninferiority of LA versus CPH flow (P < .001) and no significant differences between groups in the BMQ measures at 4 or 12 weeks. CONCLUSIONS: Extended use of an alcohol-based mouthrinse is no more likely to cause reduction in salivary flow or perceived dryness in individuals with normal salivary flow compared with a non-alcohol-based mouthrinse (CPH).

The staining potential of various currently marketed mouthrinses.

OBJECTIVES: The objectives of this clinical trial were to determine the tooth staining potential as measured by the Macpherson Modification of the Lobene Stain Index, and degree of taste alteration of four currently marketed mouthrinses when used over a 12-week period. METHODS: This investigation consisted of a 12-week, observer-blind, single-center, randomized comparison of five parallel groups of subjects. One-hundred and seventy-one subjects granting their informed consent completed the trial. Subjects were randomized to one of four currently marketed mouthrinses Crest PRO-HEALTH Rinse (CPH), Cepacol (C), Scope (S), Viadent ADVANCED CARE (V), or brushing alone (BA) with a currently marketed fluoride toothpaste. Upon randomization, subjects received a baseline stain score and then a prophylaxis to remove all extrinsic stain. Clinical assessments were repeated after six weeks and three months of product use, and subjects were asked to complete a questionnaire after the first use, at day 4, day 14, at six weeks, and 12 weeks to assess potential taste alteration. RESULTS: CPH and C demonstrated significantly (p < 0.001) more extrinsic stain after six weeks of use, and CPH, C (p < 0.001), and S (p = 0.01) after 12 weeks of use versus brushing alone with fluoride toothpaste. V was not significantly different from brushing alone at either time point. After six weeks of using the product as directed, up to 53% of subjects using CPH experienced taste interference for up to three hours post-rinse. CONCLUSIONS: The results of this study demonstrated that regular use of CPH and C mouthrinses resulted in extrinsic stain accumulation after six weeks, with increased accumulation after 12 weeks versus brushing alone.

Increasing antiplaque/antigingivitis efficacy of an essential oil mouthrinse over time: an in vivo study.

This randomized, observer-blind, parallel, controlled study determined the efficacy of an essential oils-containing (EO) antiseptic mouthrinse (in conjunction with toothbrushing) in reducing and/or controlling existing plaque or gingivitis over 6 months. Toothbrushing, combined with placebo rinsing, served as the control (C). Following ethics board approval (Biosci Research Canada, Ltd. Institutional Review Board), 139 healthy adults with mild to moderate plaque and gingivitis were randomized into EO or C groups. All subjects received oral/written instructions, monthly monitoring, and assigned unsupervised rinses. Efficacy variables were whole-mouth mean modified gingival index (MGI), Turesky modification of the Quigley Hein plaque index (PI), bleeding index (BI) at 6, 12, and 24 weeks, and data analysis through an analysis of covariance (ANCOVA) model. The EO group provided greater and increasing MGI, PI, and BI reductions than did C group over all examination periods. Compared to the C group, at 6, 12, and 24 weeks, MGI reductions for the EO group were 4.7%, 9.1%, and 20.4%, and PI reductions were 7.6%, 12.6%, and 26.3%, respectively. BI scores decreased over time and were significant compared to those for the C group (P < 0.001). Additionally, the percentages of sites improved versus baseline MGI over time for EO were 14.1%, 26.4%, and 43.3%, respectively. This study demonstrated that an EO-containing mouthrinse can provide an increasing benefit over a period of 6 months with twice daily use. This study also confirmed that an antiseptic EO rinse can provide a clinically significant benefit in reducing existing plaque and gingivitis.

Allometry of hummingbird lifting performance.

Vertical lifting performance in 67 hummingbird species was studied across a 4000 m elevational gradient. We used the technique of asymptotic load-lifting to elicit maximum sustained muscle power output during loaded hovering flight. Our analysis incorporated direct measurements of maximum sustained load and simultaneous wingbeat kinematics, together with aerodynamic estimates of mass-specific mechanical power output, all within a robust phylogenetic framework for the Trochilidae. We evaluated key statistical factors relevant to estimating slopes for allometric relationships by performing analyses with and without phylogenetic information, and incorporating species-specific measurement error. We further examined allometric relationships at different elevations because this gradient represents a natural experiment for studying physical challenges to animal flight mechanics. Maximum lifting capacity (i.e. vertical force production) declined with elevation, but was either isometric or negatively allometric with respect to both body and muscle mass, depending on elevational occurrence of the corresponding taxa. Maximum relative muscle power output exhibited a negative allometry with respect to muscle mass, supporting theoretical predictions from muscle mechanics.

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.

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.

Ranitidine, 75 mg, over-the-counter dose: pharmacokinetic and pharmacodynamic effects in children with symptoms of gastro-oesophageal reflux.

BACKGROUND: The use of over-the-counter antacids has increased in children under the age of 12 years, and has been followed by an apparent increase in the use of over-the-counter histamine-2 receptor antagonists. However, the pharmacokinetic and pharmacodynamic effects of over-the-counter histamine-2 receptor antagonists in the paediatric population are largely unknown. AIM: To evaluate the pharmacokinetics and pharmacodynamics of a single dose of the over-the-counter histamine-2 receptor antagonist, ranitidine, 75 mg, in children with symptoms of gastro-oesophageal reflux disease. METHODS: Children aged between 4 and 11 years with symptoms of heartburn suspected to be due to gastro-oesophageal reflux disease were recruited at six clinical centres. Following a single dose of either oral ranitidine, 75 mg (n=19), or placebo (n=10), recording of intragastric pH and serial blood sampling were carried out for 6 h. RESULTS: The estimated pharmacokinetic parameters of ranitidine, 75 mg, were as follows: the median Cmax value of 477 ng/mL occurred within a median of 2.5 h after dosing, and the median half-life was 2.0 h. The intragastric pH began to rise approximately 30 min after dosing with ranitidine to a peak of pH; 4. The pH in the ranitidine group remained higher than that in the placebo group throughout the 6-h evaluation period. Adverse events were generally mild. CONCLUSIONS: Ranitidine, 75 mg, significantly increased the intragastric pH in children aged 4-11 years. The pharmacokinetic and pharmacodynamic profiles were similar to those in adults. Ranitidine, 75 mg, appears to be effective for the control of intragastric acidity for 5-6 h in children aged 4-11 years.

A study of the nonprescription drug consumer's understanding of the ranitidine product label and actual product usage patterns in the treatment of episodic heartburn.

INTRODUCTION: A study of the consumer's understanding of the product label instructions and the resulting product use were conducted to support the switch of a product from prescription to nonprescription status. H2 receptor antagonists have recently been approved for nonprescription use. This study evaluated the consumer's understanding of the product label for ranitidine hydrochloride (Zantac 75) and the product usage pattern in the treatment of episodic heartburn. OBJECTIVES: Our objectives were to evaluate each aspect of the communication of labeled indications, contraindications, and directions for use of two label formats (old and new) for a new nonprescription preparation of ranitidine (Zantac) and to evaluate nonprescription consumers' use of ranitidine 75-mg tablets (as Zantac 75) in a medically unsupervised, at-home setting to observe whether these consumers used the product appropriately and followed directions as written on the package label. METHODS: Adult male and female consumers (n = 1405) in a shopping mall environment who were attracted to a poster asking, "Do you have stomach problems?" were recruited for the label comprehension phase (two different label formats) and the 3-week usage phase if after reading the Zantac 75 package label they decided the product was appropriate for them. No instructions regarding the use of Zantac 75 were provided beyond what was printed on the package label. Subjects recorded use in a diary and tablet counts were performed at the end of the study period. A medical history was also taken at this time and an assessment of product use was performed by a physician. RESULTS: In at least 84% of all subjects, both formats were effective in the communication of label objectives for the contraindication against concurrent prescription stomach ulcer medication, maximum daily dose, and maximum duration of dosing at maximum daily doses. The direction to take one tablet per dose was adhered to by 90% of consumers, and 90% of consumers followed the instructions to take no more than two tablets in 24 hours. Ninety-six percent of consumers complied with the direction not to take the maximum daily dose for more than 14 consecutive days. Notably, the maximum daily dose was taken for < or =3 consecutive days by 79% of consumers. The most frequently reported adverse events were headache, acute nasopharyngitis, upper respiratory tract infection, diarrhea, nausea, and menstrual cramps. CONCLUSION: The study demonstrated that the vast majority of a large sample of unsupervised consumers understood the package label and fully complied with the package directions by not exceeding the maximum daily dosage and length of use. Nonprescription consumers safely used Zantac 75 without medical supervision.

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.

Clinical effectiveness of essential oil-containing dentifrices in controlling oral malodor.

PURPOSE: To assess the efficacy of two essential oil-containing dentifrices in the reduction of human intrinsic oral malodor ("morning bad breath"). MATERIALS AND METHODS: Two clinical trials were conducted which used observer-blind, negative control, parallel designs. To insure a homogeneous test population with similar oral odor characteristics, subjects followed instructions that included toothbrushing with a standard ADA-accepted fluoride dentifrice the night before. On odor evaluation days, subjects refrained from all oral hygiene procedures and from eating or drinking any food or beverage or smoking prior to and during the odor evaluations. Eighty healthy adult subjects in the first trial and 90 in the second trial with qualifying baseline levels of oral malodor participated. Odor ratings of each subject's breath were made by 4-5 trained judges using a nine point hedonic scale, i.e., 1 = most pleasant, 5 = neutral, 9 = most unpleasant. Qualifying subjects were randomly assigned one of two essential oil dentifrices or a negative control dentifrice. Subjects brushed with their assigned dentifrice for 60 s, rinsed with 20 ml of water for 10 s, and received post-treatment hedonic odor ratings at 30, 60, 90, 120, 180, and 240 min. Data were analyzed using an ANCOVA to adjust for baseline scores. RESULTS: The essential oil dentifrices were significantly more effective (P < or = 0.033) than the control in reducing intrinsic oral malodor from 90 to 120 min.

Fourier-transform sum-frequency surface vibrational spectroscopy with femtosecond pulses.

We present a Fourier-transform spectroscopic technique for investigation of surfaces and interfaces based on IR-visible sum-frequency generation with femtosecond light pulses. The observed spectrum has a resolution that is independent of the input pulse characteristics.

Morphology, molecules, and the phylogenetics of cetaceans.

Recent phylogenetic analyses of cetacean relationships based on DNA sequence data have challenged the traditional view that baleen whales (Mysticeti) and toothed whales (Odontoceti) are each monophyletic, arguing instead that baleen whales are the sister group of the odontocete family Physeteridae (sperm whales). We reexamined this issue in light of a morphological data set composed of 207 characters and molecular data sets of published 12S, 16S, and cytochrome b mitochondrial DNA sequences. We reach four primary conclusions: (1) Our morphological data set strongly supports the traditional view of odontocete monophyly; (2) the unrooted molecular and morphological trees are very similar, and most of the conflict results from alternative rooting positions; (3) the rooting position of the molecular tree is sensitive to choice of artiodactyls outgroup taxa and the treatment of two small but ambiguously aligned regions of the 12S and 16S sequences, whereas the morphological root is strongly supported; and (4) combined analyses of the morphological and molecular data provide a well-supported phylogenetic estimate consistent with that based on the morphological data alone (and the traditional view of toothed-whale monophyly) but with increased bootstrap support at nearly every node of the tree.

The role of tyrosine phosphorylation in lipopolysaccharide- and zymosan-induced procoagulant activity and tissue factor expression in macrophages.

The expression of surface procoagulants by exudative macrophages represents an important mechanism underlying local fibrin deposition at sites of extravascular inflammation. The present studies investigated the contribution of tyrosine phosphorylation to the generation of macrophage procoagulant activity (PCA) and tissue factor expression in response to proinflammatory stimuli. Both lipopolysaccharide (LPS) and zymosan rapidly stimulated tyrosine phosphorylation in elicited murine peritoneal macrophages. This effect was prevented by the tyrosine kinase inhibitors genistein and herbimycin and augmented by the addition of the phosphotyrosine phosphatase inhibitor vanadate. The vanadate-mediated rise in phosphotyrosine accumulation was abrogated by the use of diphenylene iodonium, an inhibitor of the respiratory burst oxidase, suggesting a role for peroxides of vanadate as contributors to the tyrosine phosphorylation. This notion was supported by the finding that vanadyl hydroperoxide markedly increased the accumulation of phosphotyrosine residues. To define the role of tyrosine phosphorylation in the induction of macrophage PCA by LPS, the effects of tyrosine kinase inhibition by genistein and herbimycin were investigated. Both agents inhibited the expression of macrophage PCA. Further, Northern blot analysis with the cDNA probe for murine tissue factor indicated that the inhibition occurred at the mRNA level or earlier. Since vanadate augmented phosphotyrosine accumulation, it was hypothesized that it might enhance generation of macrophage products. However, vanadate reduced induction of PCA in response to LPS. By contrast, vanadate augmented basal prostaglandin E2 (PGE2) release and stimulated PGE2 release by macrophages. Indomethacin prevented the increase in PGE2 but only partially restored normal levels of PCA. The effect of vanadate on tissue factor expression appeared to be posttranscriptional. These studies thus demonstrate, by functional Western blotting and Northern blotting techniques, that tyrosine phosphorylation plays a role in the regulation of macrophage PCA and tissue factor expression in response to proinflammatory stimuli.

Cloning and regulation by glucocorticoid receptor ligands of a rat hsp90.

We have isolated a full length cDNA that encodes a heat shock protein, hsp90, from a rat brain library and present the nucleotide sequence and deduced amino acid sequence. Comparison of the entire nucleotide sequence with mouse hsp84 and human hsp90 beta cDNAs reveal sequence similarities of 92 and 87%, respectively. The coding region of 2172 nucleotides corresponds to a polypeptide chain of 724 amino acids. Comparison with mouse hsp84 and human hsp90 beta amino acid sequences indicates a similarity of 97%, respectively. Characterization of the constitutive expression of this cDNA both by RNA blot hybridization and immunoblotting, reveals that it is expressed in all rat tissues examined. Hsp90 has been shown to form a transient complex with steroid hormone receptors. In order to further elucidate the role of hsp90 in the endocrine response of cells, we have examined the effects of dexamethasone and RU38486 on the level of hsp90 mRNA in a system in which glucocorticoids down-regulate glucocorticoid receptor mRNA levels. In this system, a subtle but reproducible approx. 2-fold decrease in hsp90 mRNA levels is observed after 48 h treatment with dexamethasone.

Evaluation of the dermal effects of cast padding in coaptation casts on dogs.

Three configurations of cast padding and no cast padding were evaluated for their effects on skin in dogs. Padding was placed over bony prominences, between bony prominences, and over both areas for full-length padding under short-limb walking casts applied to 1 pelvic limb of Greyhounds. Evaluations were performed by pressure measurement over the calcaneal tuberosity, measurement of skin thromboxane B2 (TxB2) concentrations in skin over bony prominences, and measurement of plasma TxB2 concentrations. Pressure studies were performed to evaluate cutaneous pressures related to no cast padding and various configurations of cast padding. Concentrations of TxB2 in the skin were determined to evaluate the skin inflammatory effects of no padding and the padding configurations, and TxB2 concentrations in the plasma were analyzed to ascertain whether they could be used to predict impending dermal pressure lesions. Flexion of casted limbs revealed the greatest pressure over the calcaneal tuberosity with full-length cast padding. This was followed in decreasing order by no cast padding, padding over the prominences, and padding between the prominences. Compared with all other bony prominences and padding configurations, TxB2 skin concentrations were significantly higher over the calcaneal tuberosity when no padding was used and over the lateral base of metatarsal V when padding was placed between the prominences. Over the calcaneal tuberosity, this was attributed to the sharpness of the prominence and its potential for movement. This high TxB2 concentration corresponded to the high pressure found in the pressure studies. Over the lateral base of metatarsal V, the increase in TxB2 concentration was related to the mass of the prominence and the tendency for localized padding to settle around the area.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of surgical scrub and antiseptic solutions for surgical preparation of canine paws.

The purpose of the prospective study reported here was to evaluate surgical preparation of canine paws. Three combinations of surgical scrub solutions and antiseptic solutions were used: (1) 7.5% povidone-iodine scrub/10% povidone-iodine solution; (2) 2% chlorhexidine acetate scrub/2% chlorhexidine diacetate solution; and (3) tincture of green soap/70% isopropyl alcohol. The control was warm (38 to 42 C) tap water. Four microbial colony counts were used to evaluate surgical preparation of 4 paws of 8 dogs. Specimens were obtained from the paws for a baseline microbial flora count. After surgical scrub was performed, additional specimens were obtained for bacteriologic culturing. Antiseptic was applied followed by collection of another specimen for bacteriologic culturing. A final specimen was obtained following a 24-hour period under a sterile occlusive bandage. The 3 scrub solutions and the tap water control resulted in lower colony counts following scrubbing of the paws; however, only the 3 antiseptic solutions resulted in further colony count reduction after their application. Evaluation of residual colony counts isolated from specimens taken after a 24-hour period under a sterile occlusive bandage revealed chlorhexidine and povidone-iodine scrub/antiseptic combinations to be similar in antibacterial activity, with significantly (P less than or equal to 0.05) lower colony counts than those from specimens of paws treated with either the tincture of green soap/isopropyl alcohol combination or the tap water control. The lack of a significant difference between the bacterial counts immediately after surgical preparation with povidone-iodine and chlorhexidine and their respective 24-hour residual counts, indicated no particular advantage to surgical preparation and occlusive bandaging 24 hours prior to surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of chlorhexidine diacetate and povidone-iodine on wound healing in dogs.

To correlate the results of an in vitro study with clinical response, the effects of 0.005 and 0.05% chlorhexidine diacetate and 0.1 and 1.0% povidone-iodine concentrations on wound healing were evaluated in five beagle dogs. Full-thickness skin wounds (2 X 2 cm) were irrigated once daily for 14 days with the antiseptic solutions or physiologic-buffered saline. Chlorhexidine diacetate 0.05% had significantly more bactericidal activity than povidone-iodine and saline, and both chlorhexidine diacetate concentrations had residual effects 6 hours after irrigation. Neither povidone-iodine nor saline had significant bactericidal activity. The percentages of unhealed wound area and wound contraction were calculated 7, 14, and 21 days after wounding. Healed wound area and contraction were similar in wounds treated with chlorhexidine diacetate and povidone-iodine. However, wounds treated with chlorhexidine diacetate had more healed wound area on days 7 and 14 and more contraction on days 7, 14, and 21 than saline-treated wounds. At the concentrations tested, chlorhexidine diacetate irrigations provided bactericidal activity and were more beneficial to wound healing than irrigations with saline alone. These results suggest that concentrations of chlorhexidine diacetate which are cytotoxic to tissue culture fibroblasts in vitro do not interfere with wound healing in vivo.

Chlorhexidine diacetate and povidone-iodine cytotoxicity to canine embryonic fibroblasts and Staphylococcus aureus.

Chlorhexidine diacetate and povidone-iodine were evaluated for fibroblast toxicity on a primary line of canine embryonic fibroblasts, and for bactericidal efficacy against Staphylococcus aureus. The cultured fibroblasts or S. aureus were exposed for 30 minutes to incremental dilutions of 0.5 and 0.0005% chlorhexidine diacetate, 5.0 to 0.05% povidone-iodine, or physiologic buffered saline as a control. To determine survival, fibroblasts were trypsinized and counted; S. aureus colonies were counted on brain-heart infusion agar. Survival for both groups was expressed by calculating the number of living cells in test dilutions as a percentage of the number in control cultures. Fibroblast survival occurred at chlorhexidine concentrations less than 0.013% and at povidone-iodine concentrations less than 0.5% (p less than 0.05). Significant S. aureus survival (p less than 0.05) was noted at chlorhexidine concentrations less than 0.05% and povidone-iodine concentrations less than 1.0%. These data showed that all bactericidal concentrations of chlorhexidine diacetate and povidone-iodine were lethal to canine embryonic fibroblasts in vitro, whereas non-lethal concentrations allowed significant bacterial survival.

Effects of nonadherent dressing materials on the healing of open wounds in dogs.

Four types of nonadherent dressing materials (rayon/polyethylene dressing, cotton nonadherent film dressings, fine mesh gauze petrolatum dressings, and commercial petrolatum emulsion dressings) were applied on small full-thickness skin defects on the backs of 12 Beagles. At 7 days, the wounds treated with the petrolatum-containing dressings had more contraction than wounds dressed with cotton nonadherent film dressings and wounds dressed with rayon/polyethylene dressings. However, by days 14 and 21, there was little difference in the amount of contraction of any of the wounds. At 7, 14, and 21 days, the wounds dressed with petrolatum-containing dressings had less epithelialization than wounds dressed with cotton nonadherent film dressings and rayon/polyethylene dressings. The uniform open mesh of the commercial petrolatum emulsion dressings allowed the best absorption of exudate and bacteria into the secondary overlying bandage.