Are Green Household Consumer Products Less Toxic than Conventional Products? An Assessment Involving Grass Shrimp (Palaemon pugio) and Daphnia magna.

Although it is generally assumed that green household consumer products (HCPs) contain individual compounds that are less toxic and/or more degradable than conventional HCPs, little research on this topic has been conducted. In our assessments, larval grass shrimp (Palaemon pugio) were used in a biodegradation study and juvenile freshwater cladocerans, Daphnia magna, were used in a photodegradation study. In each study, organisms were exposed to nondegraded and degraded treatments consisting of one green HCP and two conventional HCPs in six different categories (laundry detergent, dish detergent, mouthwash, insecticide, dishwasher gel, and all-purpose cleaner). Sensitivity to these products were assessed using 48-h static acute toxicity tests, and the median lethal concentrations (LC50s) then compared using an LC50 ratio test. For grass shrimp, only one green HCP (insecticide) was less toxic than both conventional HCPs. In one category (laundry detergent), the green HCP was the more toxic than either conventional HCP. Following a biodegradation treatment, none of the green product formulations became less toxic, whereas 44.4% of the conventional HCPs demonstrated decreased toxicity. For daphnids, green HCPs in three categories (dish detergent, insecticide, and all-purpose cleaner) were less toxic than both conventional products tested. Following a photodegradation treatment, two green product formulations (dish detergent and dishwasher gel) became less toxic (33.3%), whereas 87.5% of the conventional HCPs demonstrated decreased toxicity. The present study demonstrates that green HCPs are not necessarily less toxic and/or more degradable than their conventional counterparts. These results also suggest that the toxicity and degradability of end-product formulations need to be considered in the overall framework for green product evaluation. Environ Toxicol Chem 2022;41:2444-2453. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Activity of Experimental Mouthwashes and Gels Containing DNA-RNA and Bioactive Molecules against the Oxidative Stress of Oral Soft Tissues: The Importance of Formulations. A Bioreactor-Based Reconstituted Human Oral Epithelium Model.

BACKGROUND: DNA-RNA compounds have shown promising protection against cell oxidative stress. This study aimed to assess the cytotoxicity, protective, or preventive effect of different experimental formulations on oral epithelia's oxidative stress in vitro. METHODS: Reconstituted human oral epithelia (RHOE) were grown air-lifted in a continuous-flow bioreactor. Mouthwashes and gels containing DNA-RNA compounds and other bioactive molecules were tested on a model of oxidative stress generated by hydrogen peroxide treatment. Epithelia viability was evaluated using a biochemical MTT-based assay and confocal microscopy; structural and ultrastructural morphology was evaluated by light microscopy and TEM. RESULTS: DNA-RNA showed non-cytotoxic activity and effectively protected against oxidative stress, but did not help in its prevention. Gel formulations did not express adequate activity compared to the mouthwashes. Excipients played a fundamental role in enhancing or even decreasing the bioactive molecules' effect. CONCLUSION: A mouthwash formulation with hydrolyzed DNA-RNA effectively protected against oxidative stress without additional enhancement by other bioactive molecules. Active compounds, such as hyaluronic acid, ß-Glucan, allantoin, bisabolol, ruscogenin, and essential oils, showed a protective effect against oxidative stress, which was not synergistic with the one of DNA-RNA. Incorporation of surfactant agents showed a reduced, yet significant, cytotoxic effect.

Abnormal cytology in oropharyngeal brushings and in oral rinses is not associated with HPV infection: The OHMAR study.

BACKGROUND: No screening is available for human papillomavirus (HPV)-associated oropharyngeal cancers. The authors investigated whether cytology may be used as a screening tool and whether oral HPV infection is associated with cytologic abnormalities detected in oropharyngeal brushings and in oral rinse-and-gargle specimens from asymptomatic individuals at increased risk for oral HPV infection. METHODS: Specimens were collected from men who have sex with men at 6-month intervals. Oropharyngeal samples and oral rinse-and-gargle specimens were collected using a cytobrush and mouthwash, respectively. Exfoliated cells were dispersed in PreservCyt. Liquid-based slides were stained with Papanicolaou. An HPV genotyping test using a linear array was used for HPV detection. Associations with abnormal cytology were investigated using logistic regression. RESULTS: Overall, 631 brushings and 802 rinses collected from 310 individuals were evaluated; of these specimens, 2 brushings (0.3%) and 10 rinses (1.2%) were inadequate for morphologic evaluation. Of the adequate samples, 35 of 629 brushings (5.5%) and 19 of 792 rinses (2.4%) were abnormal. No associations of high-risk HPVs or HPV-16 infection with cytologic abnormalities were observed for oropharyngeal brushings (high-risk HPVs: odds ratio [OR], 1.19; 95% CI, 0.41-3.50; P = .75; HPV-16: OR, 0.76; 95% CI, 0.10-5.84; P = .79) or for oral rinses (high-risk HPVs: OR, 1.13; 95% CI, 0.26-4.98; P = .87; HPV-16: OR, 0.62; 95% CI, 0.04-10.60; P = .74). Concurrent moderate/heavy drinking and smoking significantly increased the risk of cytologic abnormalities in the brushings (hazard ratio, 4.84; 95% CI, 1.15-20.43; P = .03). CONCLUSIONS: Oral HPV infection by high-risk HPVs and HPV-16 does not confer an increased risk of cytologic abnormalities in oropharyngeal brushings and oral rinses. Abnormal cytology seems to be associated with smoking and drinking habits.

Carbohydrate Mouth Rinse Fails to Improve Four-Kilometer Cycling Time Trial Performance.

We investigated if a carbohydrate (CHO) mouth rinse may attenuate global fatigue and improve 4-km cycling time trial (TT4km) performance. After a preliminary session, cyclists (n = 9) performed a TT4km after a CHO or placebo (PLA) mouth rinse. Mean power output, time, and ratings of perceived exertion (RPE) were recorded throughout the TT4km. Twitch interpolation responses (%VA; voluntary activation and ∆Tw; delta peak twitch torque) were compared pre and post TT4km with traditional statistics and effect size (ES) analysis. Time-to-complete the 4 km and mean power output were comparable between CHO (386.4 ± 28.0 s) and PLA (385.4 ± 22.4 s). A lower central (p = 0.054) and peripheral (p = 0.02) fatigue in CHO than in PLA were suggested by an extremely-large ES in %VA (manipulation main effect: p = 0.052, d = 1.18; manipulation-by-time interaction effect: p = 0.08, d = 1.00) and an extremely, very-large ES in ∆Tw (manipulation main effect: p = 0.07, d = 0.97; time-by-manipulation interaction effect: p = 0.09, d = 0.89). The RPE increased slower in CHO than in PLA (p = 0.051; d = 0.7). The apparent reduction in global fatigue (central and peripheral) and RPESLOPE with only one CHO mouth rinse were not translated into improved TT4km performance. Further tests may be required to verify if these likely differences in global fatigue might represent an edge in the short-lasting cycling time trial performance.

Sensory effects of transient receptor potential channel agonists on whole mouth saliva extensional rheology.

The extensional rheology (ER) of saliva is a property associated with its ability to coat surfaces and is important for the maintenance of a normal mouth feeling. Transient receptor potential (TRP) channels are expressed in the oral cavity and this study investigated how the sensory effects of TRP channel agonists modify the ER of saliva. Healthy volunteers rinsed with solutions containing a TRP agonist. Unstimulated whole mouth saliva (WMS) was collected prior to rinsing and WMS was collected during the first and second minutes after the mouth rinse. The Spinnbarkeit of the collected saliva was measured using a Neva Meter. The nonivamide (TRPV1) mouth rinse increased WMS ER from 37.0 (± 6.3) mm to 49.3 (± 5.1) mm when compared with the vehicle control, which itself had no effect on WMS ER. However, this effect was short-lived and ER of WMS was not increased in the second minute after the nonivamide mouth rinse. The menthol (TRPM8) mouth rinse resulted in an increase up to 57.8 (± 7.8) mm in WMS ER from the vehicle control and returned to control levels in the second minute. The cinnamaldehyde (TRPA1) mouth rinse resulted in no change in WMS ER. It can be concluded that nonivamide and menthol mouth rinsing has a short-term effect of increasing WMS ER, an effect not observed after cinnamaldehyde rinsing. We hypothesize that the activation of some TRP channels in the oral cavity results in changes in the salivary protein composition that in turn alters WMS ER. PRACTICAL APPLICATIONS: Identifying compounds that modify the physical properties of saliva in a desirable way is important in developing treatments for conditions associated with changes in the physical properties of saliva such as xerostomia (also known as dry mouth). Furthermore, understanding the rheology of saliva contributes to the elucidation of food oral processing which is of importance to food manufacturers.

Development of a buccal doxepin platform for pain in oral mucositis derived from head and neck cancer treatment.

This study describes the development of semisolid formulations containing doxepin (DOX) for pain relief in oral mucositis, frequently related to chemotherapy and/or radiotherapy treatments in patients with head and neck cancer. Chemical permeation enhancers were evaluated and selected according to the results obtained from rheological studies, drug release, and drug permeation and retention through buccal mucosa. Finally, the selected formulation was compared in vivo, with a reference DOX mouthwash, whose clinical efficacy had been previously reported. The obtained findings showed that an orabase® platform loading transcutol® (10%) and menthol (5%) for the buccal vehiculization of DOX exhibited a decreased elastic and viscous behavior improving its application. The main drug release mechanism could be considered as diffusion according to Higuchi model. Obtained DOX permeation rates were considered optimal for an analgesic effect and far below to an antidepressant activity. Similar in vivo plasma concentrations were found for the semisolid formulation and the reference mouthwash. However, DOX amounts retained in the mucosa of animals for the semisolid formulation were higher than the reference, which let us hypostatize even stronger potential local therapeutic effect with additional advantages such as, mucoadhesive properties, absence of alcohol, some degree of freshness, as well as, drug palatability improvement.

Personal care product use among adults in NHANES: associations between urinary phthalate metabolites and phenols and use of mouthwash and sunscreen.

Personal care product use is a well-established pathway of exposure for notable endocrine disrupting compounds (EDCs), including phthalates, parabens, triclosan, benzophenone-3 (BP3), and bisphenol-A. We utilized questionnaire data from the National Health and Nutrition Examination Survey 2009-2012 cycles to examine the associations between use of sunscreen and mouthwash and urinary concentrations of phthalate metabolites and phenols in a nationally representative population of US adults (n=3529). Compared with individuals who reported "Never" using mouthwash, individuals who reported daily use had significantly elevated urinary concentrations of mono-ethyl phthalate, methyl and propyl parabens, and BP3 (28%, 30%, 39%, and 42% higher, respectively). Individuals who reported "Always" using sunscreen had significantly higher urinary concentrations of triclosan, methyl, ethyl, and propyl parabens, and BP3 (59%, 92%, 102%, 151%, and 510% higher, respectively) compared with "Never" users of sunscreen. Associations between exposure biomarkers and sunscreen use were stronger in women compared with men, and associations with mouthwash use were generally stronger in men compared with women. These results suggest that sunscreen and mouthwash may be important exposure sources for EDCs.

Penetration of chlorhexidine coating into tooth enamel: A surface analytical study.

Chlorhexidine has proved an efficient antibacterial agent and has been used successfully to prevent new carious lesions in the teeth of adults and children. The substantivity of chlorhexidine has not been identified with any precision, but is certainly not of short duration. In this work, surface analytical techniques have been applied to study the chemical composition, distribution, and penetration of an applied liquid coating containing chlorhexidine onto tooth enamel in order to ascertain mechanisms by which chlorhexidine keeps its long term substantivity. Several hypotheses have been put forward with regard to its substantivity, including concepts of chlorhexidine remaining as a reservoir upon application either in the epithelial surfaces, the tooth surface, or the biofilm. Alternatively, it has been proposed the teeth themselves act as the reservoir. To study this, a chlorhexidine containing liquid coating was applied to the surface of teeth. These were subsequently transversely cross-sectioned. X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were performed on both surfaces to ascertain chemical composition and distribution of the applied coating. It was found that it formed a coating layer of about 25 µm thick. High spatial ToF-SIMS images showed little evidence of substantial diffusion of chlorhexidine into the enamel, either from the surface or via the enamel lamellae.

Carbohydrate mouth rinsing has no effect on power output during cycling in a glycogen-reduced state.

BACKGROUND: The effect of mouth rinsing with a carbohydrate (CHO) solution on exercise performance is inconclusive with no benefits observed in the fed state. This study examined the effect of CHO mouth rinse or CHO ingestion on performance in 9 moderately trained male cyclists. METHODS: Four trials were undertaken, separated by 7 days, in a randomized, counterbalanced design. Each trial included a 90-min glycogen-reducing exercise protocol, immediately followed by a low CHO meal and subsequent overnight fast; the following morning a 1-h cycling time trial was conducted. The trials included 15 % CHO mouth rinse (CHOR), 7.5 % CHO ingestion (CHOI), placebo mouth rinse and placebo ingestion. Solutions were provided after every 12.5 % of completed exercise: 1.5 mL · kg(-1) and 0.33 mL · kg(-1) body mass during ingestion and rinse trials, respectively. During rinse trials participants swirled the solution for 8 s before expectorating. Blood samples were taken at regular intervals before and during exercise. RESULTS: Performance time was not different between trials (P = 0.21) but the 4.5-5.2 % difference between CHOI and other trials showed moderate practical significance (Cohen's d 0.57-0.65). Power output was higher in CHOI relative to other trials (P < 0.01). There were no differences between CHOR and placebo groups for any performance variables. Plasma glucose, insulin and lactate concentrations were higher in CHOI relative to other groups (P < 0.05). CONCLUSIONS: In a fasted and glycogen-reduced state ingestion of a CHO solution during high-intensity exercise enhanced performance through stimulation of insulin-mediated glucose uptake. The CHO mouth rinsing had neither ergogenic effects nor changes in endocrine or metabolic responses relative to placebo.

Identification of 1,8-cineole, borneol, camphor, and thujone as anti-inflammatory compounds in a Salvia officinalis L. infusion using human gingival fibroblasts.

Drinking or gargling Salvia officinalis L. infusion (sage infusion) is thought to soothe a sore throat, tonsillitis, and inflamed, red gums, although structure-based scientific evidence for the key anti-inflammatory compounds in sage infusion is scarce. Human gingival fibroblasts (HGF-1) were treated with sage infusion (SI) or SI fractions containing either its volatile components and water (aqueous distillate, AD) or its dry matter (DM) for six hours. SI, AD, and DM reduced a mean phorbol-12-myristate-13-acetate/ionomycin (PMA/I)-stimulated release of the pro-inflammatory interleukins IL-6 and IL-8 by more than 50% (p < 0.05). Cellular uptake experiments and subsequent GC-MS analysis using stable-isotope-labeled internal standards revealed the presence of 1,8-cineole, borneol, camphor, and α-/ß-thujone in SI-treated cells; LC-MS analysis demonstrated the presence of rosmarinic acid. A significant, more than 50% mean inhibition of PMA/I-induced IL-6 and IL-8 release was demonstrated for the volatile compounds 1,8-cineole, borneol, camphor, and thujone, but not for the nonvolatile rosmarinic acid when applied in concentrations representative of sage infusion. Therefore, the volatile compounds were found to be more effective than rosmarinic acid. 1,8-Cineole, borneol, camphor, and α-/ß-thujone chiefly contribute to the anti-inflammatory activity of sage infusion in human gingival fibroblasts.

High-resolution 1H NMR investigations of the oxidative consumption of salivary biomolecules by oral rinse peroxides.

BACKGROUND: A multicomponent evaluation of the oxidative consumption of salivary biomolecules by a tooth-whitening oral rinse preparation has been performed using high-resolution proton ((1)H) nuclear magnetic resonance spectroscopy (NMR). METHODS: Unstimulated human saliva samples (n = 12) were treated with aliquots of the oral rinse tested and 600 MHz (1)H NMR spectra acquired on these samples demonstrated that hydrogen peroxide (H(2)O(2)) and/or peroxodisulphate (S(2)O(8) (2-)) present in this product gave rise to the oxidative decarboxylation of the salivary electron-donor pyruvate (to acetate and CO(2)), and also oxidized methionine (a precursor to volatile sulphur compounds responsible for oral malodour), and malodourous trimethylamine to methionine sulphoxide and trimethylamine-N-oxide, respectively (reductions observed in the salivary concentrations of each biomolecular peroxide-scavenging agent were all extremely statistically significant, p < 0.005). RESULTS: Experiments conducted on chemical model systems confirmed the consumption of pyruvate by this product, and also revealed that the amino acids cysteine and methionine were oxidatively transformed to cystine and methionine sulphoxide, respectively. CONCLUSIONS: High-field (1)H NMR analysis provides much valuable molecular information regarding the fate of tooth-whitening oxidants in human saliva and permits an assessment of the mechanisms of action of oral healthcare products containing these agents. The biochemical and potential therapeutic significance of the results obtained are discussed.

Effect of rinsing with ethanol-containing mouthrinses on the production of salivary acetaldehyde.

It has been suggested that the use of alcohol-containing mouthrinses could lead to the presence of acetaldehyde in saliva. In this cross-over study, salivary acetaldehyde levels and microbial profiles were determined before and after rinsing with ethanol-containing mouthrinses with essential oils (EO) and cetyl pyridinium chloride (CPC) as the active ingredients, and with 21.6% ethanol and water controls. After rinsing with all ethanol-containing rinses, acetaldehyde was detected in saliva after 30 s but declined to low levels after 5 min. The highest peak levels were seen with the ethanol control (median = 82.9 µM at 2 min) and were significantly higher than those seen at the same time after rinsing with the EO rinse (43.1 µM). There was no correlation between microbial counts or plaque scores and acetaldehyde levels, although dividing the subjects on the basis of a peak acetaldehyde salivary concentration of > 90.8 µM after the ethanol rinse revealed that the high responders were highly significantly more likely to harbour salivary yeasts than were the low responders. Rinsing with ethanol-containing mouthrinses causes a rapid, but transient, increase in salivary acetaldehyde levels.

Ethyl glucuronide, ethyl sulfate, and ethanol in urine after intensive exposure to high ethanol content mouthwash.

To determine the degree of ethanol absorption and the resultant formation and urinary excretion of its conjugated metabolites following intensive use of high ethanol content mouthwash, 10 subjects gargled with Listerine(®) antiseptic 4 times daily for 3» days. First morning void urine specimens were collected on each of the four study days and post-gargle specimens were collected at 2, 4, and 6 h after the final gargle of the study. Urine ethanol, ethyl glucuronide (EtG), ethyl sulfate (EtS), and creatinine were measured. Ethanol was below the positive threshold of 20 mg/dL in all of the urine specimens. EtG was undetectable in all pre-study urine specimens, but two pre-study specimens had detectable EtS (6 and 82 ng/mL; 16 and 83 µg/g creatinine). Only one specimen contained detectable EtG (173 ng/mL; 117 µg/g creatinine). EtS was detected in the urine of seven study subjects, but was not detected in the single specimen that had detectable EtG. The maximum EtS concentrations were 104 ng/mL and 112 µg/g creatinine (in different subjects). Three subjects produced a total of eight (non-baseline) urinary EtS concentrations above 50 ng/mL or 50 µg/g creatinine and three EtS concentrations exceeding 100 ng/mL or 100 µg/g creatinine. In patients being monitored for ethanol use by urinary EtG and EtS concentrations, currently accepted EtG and EtS cutoffs of 500 ng/mL are adequate to distinguish between ethanol consumption and four times daily use of high ethanol content mouthwash.

Retention of antimicrobial activity in plaque and saliva following mouthrinse use in vivo.

The aim of this study was to determine the contribution of plaque and saliva towards the prolonged activity, also called substantivity, of three antimicrobial mouthrinses (Listerine®, Meridol®, Crest Pro Health®), used in combination with a toothpaste (Prodent Coolmint®). Volunteers brushed for 4 weeks with a toothpaste without antimicrobial claims, while during the last 2 weeks half of the volunteers used an antimicrobial mouthrinse in addition to brushing. At the end of the experimental period, plaque and saliva samples were collected 6 h after oral hygiene, and bacterial concentrations and viabilities were determined. The contribution of plaque and saliva towards substantivity was assessed by combining plaque obtained after mechanical cleaning only with plaque and saliva obtained after additional use of an antimicrobial rinse. Subsequently, resulting viabilities of the combined plaques were determined. The viabilities of plaque samples after additional rinsing with mouthrinses were lower than of plaque obtained after mechanical cleaning only, regardless of the rinse involved. Moreover, plaque collected 6 h after rinsing with antimicrobial mouthrinses contained a surplus of antimicrobial activity. Only Listerine showed decreased viability in saliva, but none of the mouthrinses showed any residual antimicrobial activity in saliva. The findings indicate that plaque left behind after mechanical cleaning contributes to the prolonged substantivity of antimicrobial mouthrinses.

AG013, a mouth rinse formulation of Lactococcus lactis secreting human Trefoil Factor 1, provides a safe and efficacious therapeutic tool for treating oral mucositis.

Non-clinical studies, focusing on the pharmacodynamics (PD), pharmacokinetics (PK) and safety pharmacology of genetically modified Lactococcus lactis (L. lactis) bacteria, engineered to secrete human Trefoil Factor 1 (hTFF1), were performed to provide proof-of-concept for the treatment of oral mucositis (OM) patients. L. lactis strain sAGX0085 was constructed by stably inserting an htff1 expression cassette into the bacterial genome, and clinically formulated as a mouth rinse (coded AG013). PD studies, using different oral dosing regimens, were performed in a clinically relevant hamster model for radiation-induced OM. The PK profile was assessed in healthy hamsters and in hamsters with radiation-induced OM. In addition, in vitro and in vivo safety pharmacology studies were conducted, in pooled, complement-preserved human serum, and in neutropenic hamsters and rats respectively. Topical administration of L. lactis sAGX0085/AG013 to the oral mucosa significantly reduced the severity and course of radiation-induced OM. PK studies demonstrated that both living L. lactis bacteria, as well as the hTFF1 secreted, could be recovered from the administration site for maximum 24h post-dosing, without systemic exposure. The in vitro and in vivo safety pharmacology studies confirmed that L. lactis sAGX0085 could not survive in systemic circulation, not even under neutropenic conditions. The results from the PD, PK and safety pharmacology studies reported here indicate that in situ secretion of hTFF1 by topically administered L. lactis bacteria provides a safe and efficacious therapeutic tool for the prevention and treatment of OM.

Quantitative mapping of chlorhexidine in natural river biofilms.

Soft X-ray scanning transmission X-ray microscopy has been applied to map chlorhexidine, a ubiquitous antimicrobial agent, relative to major biochemical components (proteins, lipids, polysaccharides, Ca2+, K+, CO3(2-)) in natural river biofilms. For the first time, bio-accumulation of chlorhexidine in diatoms has been observed unambiguously. The quantitative results show that chlorhexidine bioaccumulated extensively in lipid-rich regions of diatoms and bacteria. Confocal laser scanning microscopy was used to document changes in the biofilm community. The bioaccumulation provides a significant entry point for chlorhexidine into the aquatic food chain. It results in modification of the biofilm community and it impacts the photosynthetic and protozoan species in particular. X-ray microscopy mapping at high spatial resolution is shown to be a powerful tool for studies of antimicrobial agents in the environment.

Does using a mouthwash instead of water improve the oropharyngeal removal of inhaled flovent (fluticasone propionate)?

Rinsing the mouth with water is recommended to remove inhaled corticosteroid (ICS) deposited on the oropharyngeal mucosa. Given the lipophilicity of fluticasone propionate (FP), an ethanol-based mouthwash was hypothesized to be superior to water. This study's purpose was to compare the effectiveness of water versus Listerine (Warner Lambert, Lititz, PA) in removing FP from the oropharyngeal mucosa. Asthma patients were randomly assigned water or a Listerine-rinsing vehicle. A 440-microgram dose of FP was inhaled. After the second puff, patients rinsed for 30 seconds with 20 mL of the assigned agent and then repeated the process, spitting each "wash" into the same cup. At visit 2, patients used the alternate vehicle and repeated the procedure. Samples were frozen until analyzed using liquid chromatography/mass spectrophotometry (lower limit of detection 0.067 microgram/mL). Thirty-six patients (mean age, 44 years; 66% female) participated. Mean inhaler technique score was 11.3 (scale of 1-12). Eighty-three percent used the closed-mouth technique. The mean concentration of FP removed by Listerine was not statistically different than that removed by water, 1.67 micrograms/mL (range, 0.067-4.195 micrograms/mL) and 1.42 micrograms/mL (range, 0.067-5.107 micrograms/mL), respectively, and the total milliliter returned was assumed to be 40 mL. Regression analysis using sex, age, and inhaler technique showed no statistical relationship with the amount of FP removed. Therefore, Listerine was not more effective than water in removing FP from the oropharyngeal mucosa (p = 0.53). Thus, water is an adequate rinsing vehicle for removal of ICS deposited on the oropharyngeal mucosa. Other factors besides the rinsing vehicle are strong factors in determining the amount of drug removed.

Prophylactic mineral enrichment of approximal dental plaque.

Most research on the chemical modification of dental plaque has used material from buccal and lingual smooth surfaces of teeth--plaque that is readily accessible to treatment solutions. The aim of this study was to test, on the more sheltered approximal plaque, the effect of a mouthrinse previously found to be effective in raising calcium, phosphate, and fluoride concentrations in accessible plaque. Five young adults participated in a blind, cross-over trial to compare a Ca-P-MFP-urea test rinse and a NaCl placebo rinse. For 6 days, subjects rinsed twice per day after their normal toothbrushing, using 10 ml of rinse solution for 30 seconds and a fresh 10 ml for a further 30 seconds. A non-fluoride toothpaste was used and normal flossing was withheld. Plaque was collected before rinsing and again 16 hours after the final rinse from all approximal sites except those between the lower anterior teeth. Pre- and post-rinse calcium values were 291 +/- 100 and 511 +/- 107 nmol/mg protein (mean +/- SD) respectively for the test rinse, and 368 +/- 223 and 306 +/- 125 nmol/mg protein respectively for the placebo. Analysis of variance showed that the test rinse had a significant effect on plaque calcium but not on phosphate or fluoride. Mean calcium values of about 2,400 nmol/mg protein have been obtained previously in smooth-surface plaque after use of the test rinse. The reduced effect here is probably due to restricted access of the rinse solution.

Systemic absorption of a leucovorin mouth wash: a pharmacologic study.

Mucositis is one of the major problems encountered after the administration of systemic chemotherapy. Leucovorin, routinely used as a rescue agent for methotrexate may reduce toxicity, but may also reduce the effectiveness of the chemotherapeutic agent. If leucovorin is administered as a mouth wash, local toxicity may be reduced without loss of methotrexate efficacy. In order to study this, 15 normal human volunteers were given leucovorin mouth wash and then had plasma determinations of 5-methyl-tetrahydrofolate and citrovorum factor. Small but statistically significant increases in plasma levels of 5-methyl-tetrahydrofolate were observed with no increase in levels of plasma citrovorum factor. It is concluded therefore that a small amount of leucovorin is absorbed systemically when administered as a mouth wash, but such an amount would most likely not be significant enough to reduce the effect of methotrexate therapy, but may reduce mucositis.

Oral retention and discoloration tendency from a chlorhexidine mouth rinse.

Individual differences in tooth discoloration have been observed after using chlorhexidine mouth rinses. To study the correlation between retention of chlorhexidine and the discoloration tendency, two groups, 'stainers' and 'non-stainers', were selected. The following parameters were tested: initial retention of chlorhexidine in vivo, retention of chlorhexidine to saliva-coated hydroxyapatite in vitro, and prolonged release of chlorhexidine in vivo. The initial oral retention of chlorhexidine was identical for the two groups, whereas in vitro retention of hydroxyapatite and prolonged release of chlorhexidine in vivo were higher among 'stainers'.