Effect of amine and stannous fluoride on human neutrophil functions in vitro

Comparative efficacy of stannous fluoride and copper sulfate footbath solutions for the treatment and prevention of digital dermatitis in lactating dairy cows

The objective of this study was to determine whether a novel footbath solution containing stannous fluoride (SnF2) was superior to 5% copper sulfate solution for the treatment and prevention of digital dermatitis (DD) in dairy cattle. Study 1 was conducted over 4 weeks in Missouri and involved 34 lactating Holstein-Friesian cows with hind feet DD lesions. Cows in group SF walked through a footbath containing a proprietary formulation of SnF2 once weekly, whereas cows in group CS walked through a 5% CuSO4 footbath once daily for 5 d each week. Study 2 was conducted over 8 weeks in California and involved 40 lactating Holstein-Friesian cows with hind feet DD lesions. Cows in group SF walked through a SnF2 footbath for 3 consecutive days then once a week for the following 7 weeks. Cows in group CS walked through a 5% CuSO4 footbath 3 times each week for 8 weeks. Data collection included lesion type, lesion area, locomotion score, and pain score. Digital dermatitis was actively transmitted in study 1, and lesion area and locomotion scores were lower in group SF than group CS. In contrast, DD was not actively transmitted in study 2, and lesion area and locomotion scores were similar in groups SF and CS. Stannous fluoride delayed the development of active DD lesions in study 1 compared with copper sulfate, with a lower relative risk (0.57, P < 0.001) of a hind foot developing an active DD lesion over 28 d. However, SnF2 decreased the rate that active DD lesions transitioned to M3, M4, or M0 lesions compared with 5% copper sulfate in both studies, with the relative risk of a hind foot with an active DD lesion transitioning to M3, M4, or M0 in group SF being slightly lower in study 1 (0.83, P = 0.042) and study 2 (0.90, P = 0.020) than group CS. Our findings demonstrated that walking cows through a stannous fluoride footbath once per week in a herd undergoing active transmission of infection was more effective in preventing active DD lesions, but less effective in treating active DD lesions, than walking cows through a copper sulfate footbath 4 times per week. The novel SnF2 footbath solution shows promise for controlling DD in dairy herds that want an alternative footbath solution to CuSO4 and are interested in limiting the environmental accumulation of copper.

Fluoride ion release and solubility of fluoride enriched interim cements

STATEMENT OF PROBLEM

Interim and definitive restorations cemented with interim cements for a prolonged interval are susceptible to bacterial infiltration and caries formation.

PURPOSE

The purpose of this in vitro study was to evaluate the long-term fluoride release and solubility of aged ZnO-based interim cements enriched separately with 0.4% NaF and SnF2.

MATERIAL AND METHODS

Four different brands of cements (Tempbond, Tempbond NE, Procem, and Freegenol) were tested for fluoride release and solubility. For every test, 6 disk specimens of each cement with NaF and SnF2, and 6 with no fluoride enrichment (control) were fabricated, for a total of 72 specimens. The disks were incubated in deionized water. Fluoride ion release was recorded at 1, 7, 14, 21, 63, 91, and 182 days. Solubility was calculated as weight percent after 90 days of incubation. The data were analyzed by analysis of variance with repeated measures and the Tukey honestly significant difference post hoc test (P<.05).

RESULTS

Cements mixed with fluorides released fluoride ions for at least 182 days. Cements mixed with NaF released more fluoride ions than those mixed with SnF2 (P<.001). The cumulative release rates from all the tested cements mixed with either NaF or SnF2 were linear with respect to t(½) (r>.97), indicating a diffusion-controlled fluoride release. Cement and fluoride types were the main affecting factors in fluoride ion release. The addition of fluorides slightly increased the solubility of the cements.

CONCLUSIONS

Given their long-term sustained and diffusive controlled release, these fluorides, particularly NaF when mixed with ZnO-based interim cements, may be useful for caries prevention under provisionally cemented restorations.

Electrochemical behaviour of titanium in ammine and stannous fluoride and chlorhexidine 0.2 percent mouthwashes

Titanium (Ti) is widely used in dentistry. Fluorides at acid pH could destabilize Ti oxide and make it susceptible to corrosion. The behaviour of IV grade machined Ti disks in 5 electrolytic solutions: Fusayama artificial saliva (Fas), ammine fluoride-stannous fluoride (Am-SnF2), 0.2 percent Chlorexidine (CHX) 0.20 percent, Fas with 20 percent Am-SnF2, and Fas with 20 percent CHX, was evaluated. Open circuit potential Ecorr was determined by immersing Ti disks for 24 hours in an electrochemical cell containing the solutions, potential changes were measured until a stable value was obtained. Examination by Scanning Electronic Microscope and Energy Dispersive X-ray Analysis were then performed. One way ANOVA analysis showed a significant difference of Ecorr values regarding the 5 solutions (p less than 0.001). The highest values were observed for Fas (-37.6 mV), intermediate for Am-SnF2 (-81mV) and lowest for CHX (-87.6mV). SEM analysis of disks after polarization curve in CHX showed a marked localized corrosion, while the other solutions showed no considerable corrosive action on Ti surface. When considering corrosive potential range in oral cavity, Ti had an excellent behaviour on both antiseptics evaluated. The results obtained in this study will enable us to recommend the use of Am-SnF2 mouthwash for patients with dental implants.

Exogenous factors in the immunotoxicity of oral PMN

Current evidence indicates that periodontal disease is frequently due to inappropriate levels of gingival granulocyte functions. Reason of this failure may be the toxic effects of a number of local or systemic exogenous factors, capable of spreading through the gingival crevice environment, and strongly conditioning the granulocyte activities. The wide list includes bacteria and granulotoxic products, hedonistic drugs (mainly tobacco), and chemotherapeutic agents (especially antimicrobials used for preventing or reducing the accumulation of dental plaque). Almost always, their presence induces a time- and/or dose-dependent toxicity.

Effect of local antimicrobial agents on excisional palatal wound healing: a clinical and histomorphometric study in rats

AIM

To assess the effect of topically applied antimicrobial agents on palatal excisional wound in rats.

MATERIALS AND METHODS

Excisional wounds, 5 mm in diameter, were made in the centre of the palate of 125 Wistar male rats. In four experimental groups, chlorhexidine digluconate (CHX) 0.12% solution, 1% CHX gel, phenolic compounds solution (Listerine), amine/stannous fluoride solution (Meridol) and saline solution as a control group were applied daily for 1 min. The wound area was measured photographically and the epithelialization rate was determined histologically at 3, 7, 14 and 21 days post-surgery.

RESULTS

The mean wound area and mean distance between the epithelial margins decreased significantly with time (p<0.001) in experimental and control groups, with the greatest wound area reduction and rate of epithelialization on day 14. A significantly superior rate of wound epithelialization (p=0.03) was presented following use of 1% CHX gel and Listerine and a comparatively inferior one when the Meridol solution was applied.

CONCLUSIONS

Each tested antimicrobial agent when applied on an excisional wound with epithelial and connective tissue deficiency did not have a negative effect on the rate of wound closure. The best results were achieved with 1%CHX gel and Listerine.

Evaluation of additional amine fluoride/stannous fluoride-containing mouthrinse during supportive therapy in patients with generalized aggressive periodontitis. A randomized, crossover, double-blind, controlled trial

OBJECTIVES

The objective of the present randomized controlled trial was to evaluate the efficacy of a mouthrinse containing a combination of AmF/SnF2 in controlling supragingival plaque accumulation and gingival inflammation during a 12-week period in patients affected by generalized aggressive periodontitis (GAP).

METHODS

Eighteen subjects, six males and 12 females, mean age: 32.2 years, were evaluated. One-half of the patients was either prescribed an AmF/SnF2-containing mouthrinse (test mouthrinse) or a control mouthrinse in addition to mechanical plaque control for 12 weeks. After a 2-week wash-out period, the patients received the alternative mouthrinse. Before and after treatment plaque index (PlI), gingival index (GI), angulated bleeding index (AngBI), tooth stain (GMSI), and tongue stain were recorded.

RESULTS

Test mouthrinse resulted in a statistically significant decrease in PlI (p = 0.029) and GI (p = 0.017). After treatment, PlI was significantly lower in test compared to control mouthrinse (p = 0.027). GMSI significantly increased post-treatment for both mouthrinse regimens (p < 0.001), a significantly higher score being observed for the test compared to control mouthrinse (p = 0.002).

CONCLUSIONS

The 12-week use of a AmF/SnF2-containing mouthrinse as an adjunct to conventional mechanical oral hygiene procedures in GAP patients was effective in controlling the amount of supragingival plaque deposits.

Modulation of clinical expression of plaque-induced gingivitis. III. Response of "high responders" and "low responders" to therapy

AIM

The aim of the present study was to characterize the subject-based clinical behavior of the gingiva in response to a tooth-cleaning regimen in two subpopulations, "high-responder" (HR) and "low-responder" (LR) groups, presenting a different inflammatory response to plaque accumulation.

MATERIAL AND METHODS

The study population comprised of 96 systemically and periodontally healthy subjects, 46 males and 50 females, non-smokers, enrolled in an experimental gingivitis trial. At completion of the experimental gingivitis period (day 21), all subjects were prescribed the same 21-day treatment regimen of amine/stannous fluoride (AmF/SnF(2))-containing toothpaste and mouthrinse. Plaque index (PlI), gingival index (GI), gingival crevicular fluid volume (GCF), and angulated bleeding score (AngBS) were recorded on three selected teeth. Treatment efficacy was evaluated in the overall population as well as in HR and LR groups, separately.

RESULTS

A statistically significant decrease of PlI was observed after treatment (p<0.001), with PlI reversing to baseline levels. Changes in PlI revealed the same trend in both HR and LR groups, without differences between groups. Treatment also resulted in a significant decrease of all gingivitis parameters (p<0.001 for all comparisons). After treatment, GI, AngBS, and GCF were comparable with baseline condition. However, when the two groups were compared, day 42-GCF was significantly higher in the HR group than the LR group.

CONCLUSIONS

A treatment regimen based on mechanical plaque control supplemented with AmF/SnF(2)-containing toothpaste and mouthrinse is effective in reducing plaque accumulation and re-establishing healthy gingival conditions after experimentally induced gingivitis, even in subjects with different inflammatory response to plaque accumulation.

Modulation of clinical expression of plaque-induced gingivitis. I. Background review and rationale

OBJECTIVES

The purpose of this article is to provide the necessary background and rationale for the accompanying studies, which are ultimately aimed at identifying genetic and environmental factors determining gingivitis susceptibility.

MATERIALS AND METHODS

The literature on factors reported to modify the clinical expression of gingivitis, i.e., factors that determine individual variability in gingival inflammatory response to plaque, is presented.

RESULTS

Clinical evidence suggests that the gingival inflammatory response to plaque accumulation may differ substantially among individuals. However, most of the available studies are of small scale and not purposely designed to address the issue. Systemic factors implicated in modulation of the clinical expression of gingivitis include metabolic, genetic, environmental and other factors. The significance of such factors in designing and conducting a large-scale experimental gingivitis trial and means to account for them are discussed.

CONCLUSION

Although several factors have been implicated, genetic or environmental factors underlying differences in gingivitis expression are not fully elucidated. The accompanying studies aim to identify and characterize, among participants in a specifically designed large-scale experimental gingivitis trial, subjects that differ significantly in their gingival inflammatory response to plaque. This is the first step in an effort to determine genetic or environmental factors underlying such differences.

Effectiveness of stannous fluoride and calcium hydroxide against Enterococcus faecalis

The objective of this study was to evaluate the antimicrobial activity of stannous fluoride, calcium hydroxide, or the two in combination against Enterococcus faecalis. Fifteen Mueller-Hinton agar plates were used to conduct a disc diffusion susceptibility test. The plates were inoculated with E. faecalis. The groups tested were: (a) stannous fluoride (Stanimax); (b) calcium hydroxide; and (c) a combination of stannous fluoride and calcium hydroxide. Three filter paper discs, each soaked with one of the groups, were placed along with an antibiotic control (ampicillin) on each agar plate. The plates were then incubated at 37 degrees C. The zones of inhibition were measured at 24 and 48 h. One-way ANOVA revealed a statistically significant difference (p < 0.05) between the three groups. Stannous fluoride displayed the widest zone (1.7 mm), followed by the combination of stannous fluoride and calcium hydroxide (1.1 mm), whereas calcium hydroxide by itself displayed a minimal zone of inhibition (0.05 mm).

Amine fluoride gel affects the viability and the generation of superoxide anions in human polymorphonuclear leukocytes: an in vitro study

Amine hydrofluorides are widely used to prevent caries. As an acidulated gel, they were also studied for their applicability to reduce pathogenic bacteria in periodontal pockets. We assessed the toxicity of this pharmaceutical amine hydrofluoride preparation on human polymorphonuclear leukocytes in vitro by measuring Trypan blue exclusion and the generation of superoxide anions (O2) by the chemotactic peptide N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP) after a 3-min contact with gel. Depending on the experimental conditions, gel dilutions up to 1.3 x 10(4) resulted in an increase in Trypan blue-colored cells and liberation of beta-glucuronidase. Dilutions between 3 x 10(4) and 1 x 10(5) augmented the fMLP-mediated O2- generation, which could be prevented by Ca2+ chelation with BAPTA-AM (1,2'-bis (o-aminophenoxyethane-N.N.N'.N'-tetraacetic acid tetra (acetoxymethyl) ester) and ethyleneglycoltetraacetic acid (EGTA) or inhibition of protein kinase C (PKC) with staurosporine and bisindolylmaleimide I. respectively. Compared with data published on the minimal inhibitory concentration for periodontal pathogenic bacteria, the cytotoxicity of amine hydrofluorides on eukaryotic cells is much greater and thus of consequence for their clinical use.

One-year compliance and effects of amine and stannous fluoride on some salivary biochemical constituents and oral microbes in institutionalized elderly

Due to old age and poor general health, the institutionalized elderly have often not been used as research subjects for the investigation of oral health protocols. Because the number of elderly is increasing, they are an important target group for the development of oral hygiene aids. This trial was designed to investigate whether the institutionalized elderly could successfully use an amine-fluoride- and stannous-fluoride-containing mouthwash and toothpaste during a 12-month period. A dental hygienist visited the subjects weekly, instructed them, and recorded their self-reported compliance. Plaque and saliva samples were taken at three-month intervals. Some salivary biochemical constituents reflecting mucosal integrity were analyzed. The carrier status of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Bacteroides forsythus, Prevotella intermedia, and Prevotella nigrescens was studied by the polymerase chain-reaction method, and acidogenic bacteria and yeasts by dip-slide methods (Orion Diagnostica, Espoo, Finland). Of those 98 subjects originally included, 44 elderly (30 women and 14 men; mean age, 81.7 +/- 5.9 yrs) completed the trial. Their observations were positive or very positive regarding the use of mouthwash and toothpaste. The number of residents with P. gingivalis decreased statistically significantly throughout the trial, while the carrier status of the other periodontal bacteria and mutans streptococci remained on the same level. The number of subjects with high counts (> or = 10(5) cfu/mL) of yeasts decreased during the study: 26.2% at baseline, 9.1% one year later, respectively. Biochemical analyses of salivary immunoglobulins showed no effect on IgA and IgM levels, but IgG reduced significantly. Albumin and other salivary protein concentrations were found to have a decreasing tendency. Thus, the overall effect of the protocol was beneficial with regard to subjects' oral health as measured in this study. The residents were pleased to participate, but the number of drop-outs was very high, confirming the expected difficulties with the utilization of a group of frail elderly as research subjects.

Oxidative injury and inflammatory periodontal diseases: the challenge of anti-oxidants to free radicals and reactive oxygen species

In recent years, there has been a tremendous expansion in medical and dental research concerned with free radicals, reactive oxygen species, and anti-oxidant defense mechanisms. This review is intended to provide a critical, up-to-date summary of the field, with particular emphasis on its implications for the application of "anti-oxidant therapy" in periodontal disease. We have reviewed the nomenclature, mechanisms of actions, features, and sources of most common free radicals and reactive oxygen species, as well as analyzed the typical biological targets for oxidative damage. Based on a review of direct and indirect anti-oxidant host defenses, particularly in relation to the key role of polymorphonuclear neutrophils in periodontitis, we review current evidence for oxidative damage in chronic inflammatory periodontal disease, and the possible therapeutic effects of anti-oxidants in treating and/or preventing such pathology, with special attention to vitamin E and Co-enzyme Q.

The effect of extracellular polysaccharides from Streptococcus mutans on the bactericidal activity of human neutrophils

Extracellular polysaccharides (PS) synthesized by oral bacteria constitute one of their major virulence factors. The PS, synthesized from sucrose, facilitate adhesion and colonization by bacteria to tooth surfaces. The study was designed to test the effect of in situ production of extracellular PS by Streptococcus mutans on the bactericidal activity of human neutrophils. These effects were tested on bacteria pre-exposed to sucrose (PS-positive Strep. mutans) and compared to bacteria not exposed to sucrose (PS-negative Strep. mutans). The interactions between neutrophils and Strep. mutans were tested in suspension and on bacteria in an experimental model of dental plaque. Viability of Strep. mutans was measured by [3H]-thymidine incorporation into the bacteria. Degranulation of neutrophils was evaluated by the release of lysozyme, and the production of reactive oxygen products was measured by chemiluminescence. When neutrophils were incubated with suspended bacteria, the viability of PS-negative Strep. mutans was 20% of that of bacteria not incubated with neutrophils (control), while the viability of PS-positive Strep. mutans was 40% of the control. In the experimental dental-plaque model, 50% of the PS-negative Strep. mutans were killed by neutrophils while the viability of PS-positive Strep. mutans was not different than of the control. Degranulation of neutrophils was not affected by the presence of extracellular PS of Strep. mutans. Artificial stimulation of neutrophils with phorbol myristate acetate also did not enhance the bactericidal effect of neutrophils on PS-positive Strep. mutans. However, PS-positive Strep. mutans elicited oxygen-reactive products from neutrophils, 2-fold less than with PS-negative Strep. mutans. The results indicate that in situ production of bacterial extracellular polysaccharides might be a major virulence factor of Strep. mutans, enabling PS-positive Strep. mutans in the dental-plaque biofilm to evade killing by human neutrophils.