Gingivitis efficacy of a 0.454% w/w stannous fluoride dentifrice: a 24-week randomized controlled trial.

BACKGROUND: Plaque-induced gingivitis can be prevented and treated with regular effective oral hygiene, principally via mechanical cleaning with regular toothbrushing. To complement the mechanical plaque removal, antimicrobial ingredients can be incorporated into dentifrices to inhibit the growth of plaque. This study aimed to evaluate and compare gingivitis and the proportion of subjects moving between gingivitis severity (< 10, > 10 < 30, > 30% bleeding sites), and plaque reduction, following twice daily use of an experimental non-aqueous 0.454% weight/weight (w/w) stannous fluoride (SnF2) dentifrice, compared to a negative control dentifrice over 12 and 24 weeks. METHOD: This was a single-center, examiner-blinded, randomized, stratified, two-treatment arm, parallel group, 24-week clinical study in healthy adult volunteers with moderate gingivitis. At baseline, after abstaining from toothbrushing overnight, subjects underwent MGI (modified gingival index), BI (bleeding index) and PI (plaque index) assessments. Eligible subjects, who met the inclusion/exclusion criteria, were stratified based on gender and baseline mean MGI score (Low ≤2.00 /High > 2.00) and randomized to treatment. Following randomization, subjects underwent a thorough dental prophylaxis and flossing. After 12 and 24 weeks of twice daily brushing with their allocated treatment, subjects returned to the site (with overnight plaque, having abstained from oral hygiene procedures for 8 h prior to visit) for MGI, BI and PI assessments. Treatment effect was evaluated by comparing the MGI, BI and PI scores. RESULTS: One hundred and twenty-nine subjects were screened; 98 subjects were randomized and 90 subjects completed the study. Statistically significant differences between treatments, in favour of the 0.454% stannous fluoride dentifrice were observed, compared to the negative control dentifrice, for all outcome measures (MGI, BI, bleeding sites and PI at weeks 12 and 24 p < 0.0001). At 24 weeks, 71% of subjects in the 0.453% SnF2 treatment group demonstrated < 10% of bleeding sites. CONCLUSION: A dentifrice containing 0.454% w/w SnF2 was shown to be superior to a standard dentifrice in controlling gingivitis and supra-gingival plaque, over a 24-week period. Over two thirds of subjects in the 0.454% SnF2 treatment group demonstrated a level of bleeding sites potentially representative of "clinical periodontal health" (< 10%) following a dental prophylaxis and 24 weeks of product use. TRIAL REGISTRATION: This study was retrospectively registered at ClinicalTrials.gov, on 11th Oct. 2019 (NCT04123665).

Effectiveness of antimicrobial gels on gingivitis during fixed orthodontic treatment: A systematic review and meta-analysis.

OBJECTIVE: The present study was aimed to assess the effectiveness of antimicrobial gels along with conventional tooth brushing to improve gingival health in patients undergoing fixed orthodontic treatment. MATERIALS AND METHODS: All randomized and non-randomized clinical trials done on human subjects were explored in major health science databases (PubMed, CINAHL Plus, EBSCO Dent & Oral Sciences and Cochrane). An additional manual search was done on Google Scholar and on www.clinicaltrials.gov to identify any grey literature and unpublished data. Date of publication was not restricted during the data search. The assessment of risk of bias was done using the Cochrane Collaboration's Risk of Bias assessment tool. The meta-analysis was done using Review Manager Version 5.3.5 to analyse probing depth to be in two and four-week follow-up. This systematic review is reported according to the PRISMA statement and registered at PROSPERO (CRD42018084530). RESULTS: The electronic database search yielded 3733 records; hand search identified 14 articles meeting the selection criteria which were included in the qualitative data synthesis. Significant improvement in gingivitis has been reported using antioxidant-essential oil gel, cervitec gel (0.2% chlorhexidine), 2% chlorhexidine gel, amine fluoride gel, and 0.4% stannous fluoride gel with>98% availability of Sn+2 ions. Three articles with probing depth as comparable parameter were used for quantitative analysis. At the two and four-week follow-up, overall insignificant differences were observed in the antimicrobial gel group compared to the control group with regard to probing depth. CONCLUSIONS: The use of antioxidant-essential oil gel, amine fluoride gel, 0.4% stannous fluoride gel (98% availability of Sn+2) and 2% chlorhexidine gel resulted in significant improvement in gingivitis. However, probing depth in follow-up visits showed no significant difference between antimicrobial gel and control group.

Clinical effect of stannous fluoride and amine fluoride containing oral hygiene products: A 4-year randomized controlled pilot study.

This 4-year randomized controlled trial (RCT) aimed at investigating whether routine home use of both a SnCl2/AmF/NaF-containing mouth rinse and toothpaste has a preventive effect on oral health. Fifty-four test subjects were examined in biannual intervals. The primary endpoint "dental erosion" was determined by the Basic Erosive Wear Examination (BEWE). The secondary endpoints were "saliva pH", "dentin hypersensitivity" generated by Visual Analogue Scale (VAS), and "discoloration" measured by the Lobene Stain Index (LSI). A mixed model for repeated measures (MMRM) was used to analyze the primary endpoint "dental erosion". Primary analysis showed a significant intervention effect of the SnCl2/AmF/NaF-containing test product (p1 = 0.0242). This result was confirmed by two additional MMRM-based sensitivity analyses. Comparison of all models showed "dental erosion" values of the intervention group  below values of the control group. Discoloration of the teeth was significantly higher in the intervention than in the control group at all time points. Saliva pH and dentin hypersensitivity were not significantly different between groups over four years. In summary, this RCT is the first to indicate a possible preventive effect of SnCl2/AmF/NaF-containing oral hygiene products on dental erosion over a follow-up period of four years.

Unexpected sequel to silver fluoride followed by stannous fluoride treatment of root stumps supporting an overlay denture in an aged-care patient.

An institutionalized high care dementia patient, who is unable to maintain his own oral health, presented with five lower anterior carious root stumps supporting a lower overlay denture. Due to limited cooperation, his root stumps were treated with only silver fluoride followed by stannous fluoride applied topically on a 4-monthly cycle. Almost one and a half years after his initial application, there were unexpected calculus formations on the root stumps accompanied by marked gingival inflammation and gingival hyperplasia. At this point prognosis was considered very poor. Because the patient's cooperation was so poor, no attempt was made to remove the calculus deposits. Following continued topical applications directly to the area, there was evidence of a marked and unexpected improvement in gingival health. Some 4 years and 4 months after the initial application, the root stumps demonstrated a hard glossy surface surrounded by healthy gingival tissue. There had been no change in the patient's oral care, minor changes to medications and there had been no operative or periodontal interventions.

A Comparison of Oral Hygiene Products and Professional Care: A six-week randomized clinical trial.

Purpose: To investigate the anti-gingivitis efficacy of a novel oral hygiene routine consisting of a two-step stannous fluoride dentifrice and hydrogen peroxide whitening gel system, an interactive oscillating-rotating electric toothbrush, and expanded polytetrafluoroethylene floss.Methods: A total of 52 participants (n=52;mean age 35.8±11.23 years) were enrolled in the study and randomized 1:1 to the experimental hygiene group or control (dental prophylaxis followed by use of standard sodium fluoride dentifrice and a manual toothbrush). Participants were instructed to brush twice daily; those in the experimental group were instructed to floss once daily. Oral examinations were conducted at Baseline, Week 2, Week 4, and Week 6.Results: Both groups experienced significant declines in the mean number of bleeding sites from Baseline at all time points, evident as early as Week 2. Bleeding sites continued to decline throughout the trial in the experimental group, whereas they showed an increasing trend between Weeks 2 and 6 in the control group. The experimental group had 55% fewer bleeding sites at Week 2, 85% fewer bleeding sites at Week 4, and 98% fewer bleeding sites at Week 6 (p<0.0001 for all) as compared to the control group. At Week 6, 84% of participants in the experimental group had no bleeding, while all participants in the control group had bleeding.Conclusion: The experimental oral hygiene group showed significantly greater reductions in gingival bleeding than the control oral hygiene group, with benefits seen as early as Week 2 and increasing over the six-week study.

Antibacterial Effects of Toothpastes Evaluated in an In Vitro Biofilm Model.

PURPOSE: To test the antibacterial effects of different toothpastes with the slurry method of toothpaste application in an in vitro oral biofilm model including relevant periodontal pathogens. MATERIALS AND METHODS: Four commercially available toothpastes, two containing sodium fluoride (NaF) at different concentrations (1450 and 2500 ppm), two NaF with either triclosan or stannous fluoride, and a control phosphate-buffered saline (PBS) were used. Multispecies biofilms containing 6 species of oral bacteria were grown on hydroxyapatite disks for 72 h and then exposed for 2 min to the toothpaste slurries or phosphate buffer saline (PBS) by immersion, under continuous agitation at 37°C. Biofilms were then analysed by means of real-time polymerase chain reaction (PCR), combined with propidium monoazide (PMA). Statistical evaluation was performed using ANOVA and Student's t-test, with Bonferroni correction for multiple comparisons. RESULTS: The toothpastes containing NaF and stannous fluoride demonstrated superior antimicrobial activity for A. actinomycetencomitans, P. gingivalis and F. nucleatum when compared to those containing NaF and triclosan, 1450 ppm NaF or 2500 ppm NaF in this multispecies biofilm model. CONCLUSION: The proposed model for the evaluation of toothpastes in the form of slurries detected significant differences in the antimicrobial effects among the tested NaF-containing toothpastes, with the stannous fluoride-based formulation achieving better results than the other formulations. The use of toothpaste as slurries and real-time PCR with PMA is an adequate method for comparing the in vitro antimicrobial effect of different toothpastes.

Efficacy of two mouthwashes on 3-day supragingival plaque regrowth: a randomized crossover clinical trial.

BACKGROUND: The aim of this study was to evaluate the antiplaque effects of an alcohol-free essential oil (alcohol-free EO) mouthwash and an amine fluoride/stannous fluoride with zinc lactate (SnFl-Zn) mouthwash compared to a positive control of chlorhexidine (CHX) mouthwash, using an in vivo plaque regrowth model of 3 days. MATERIALS AND METHODS: The study was designed as a double-masked, randomized, crossover clinical trial, involving 20 volunteers to compare two different mouthwashes, using a 3-day plaque accumulation model. After receiving thorough professional prophylaxis at baseline, over the next 3 days, each volunteer refrained from all oral hygiene measures and performed two daily rinses with 20 ml of the test mouthwashes. A 0.20% CHX rinse served as a positive control. At the end of each experimental period, plaque was assessed, and the panellists completed a questionnaire. Each subject underwent a 14-day washout period, and then, there was another allocation. RESULTS: The SnFl-Zn mouthwash has shown a better inhibitory activity on plaque regrowth compared to the alcohol-free EO mouthwash in the whole mouth (plaque index = 1.93 against 2.45, respectively), but there was less of an effect compared to the CHX group, with an overall plaque index of 1.41. The differences of 0.52 between alcohol-free EO and SnFl-Zn and between SnFl-Zn and CHX and of 0.96 between alcohol-free EO and CHX were all statistically significant (P < 0.001). CONCLUSION: The alcohol-free EO mouthwash seemed to have less of an inhibiting effect on plaque regrowth than the amine fluoride/SnFl-Zn mouthwash and the CHX control.

Effect of Fluoride-Containing Toothpastes on Enamel Demineralization and Streptococcus mutans Biofilm Architecture.

This study aimed to explore the effect of fluoridated toothpastes on biofilm architecture and enamel demineralization in an in vitro biofilm model. Streptococcus mutans was grown on enamel and treated with slurries of commercial toothpastes, containing SnF2 or NaF. Water and chlorhexidine were used as negative and positive controls, respectively. The developed biofilms were imaged and enamel demineralization was measured. SnF2 and NaF toothpaste treatments significantly reduced enamel demineralization, but SnF2 toothpaste was more effective. Only SnF2 toothpaste and chlorhexidine treatments caused reductions on biofilm mass and thickness. In conclusion, this biofilm model was able to differentiate the effects of the SnF2 and NaF toothpastes on biofilm architecture and enamel demineralization.

Re- and Demineralization Characteristics of Enamel Depending on Baseline Mineral Loss and Lesion Depth in situ.

OBJECTIVES: The aim of this double-blinded, randomized, cross-over in situ study was to evaluate the re- and demineralization characteristics of sound enamel as well as lowly and highly demineralized caries-like enamel lesions after the application of different fluoride compounds. METHODS: In each of three experimental legs of 4 weeks, 21 participants wore intraoral mandibular appliances containing 4 bovine enamel specimens (2 lowly and 2 highly demineralized). Each specimen included one sound enamel and either one lowly demineralized (7 days, pH 4.95) or one highly demineralized (21 days, pH 4.95) lesion, and was positioned 1 mm below the acrylic under a plastic mesh. The three randomly allocated treatments (application only) included the following dentifrices: (1) 1,100 ppm F as NaF, (2) 1,100 ppm F as SnF2 and (3) 0 ppm F (fluoride-free) as negative control. Differences in integrated mineral loss (x0394;x0394;Z) and lesion depth (x0394;LD) were calculated between values before and after the in situ period using transversal microradiography. RESULTS: Of the 21 participants, 6 did not complete the study and 2 were excluded due to protocol violation. Irrespectively of the treatment, higher baseline mineral loss and lesion depth led to a less pronounced change in mineral loss and lesion depth. Except for x0394;x0394;Z of the dentifrice with 0 ppm F, sound surfaces showed significantly higher x0394;x0394;Z and x0394;LD values compared with lowly and highly demineralized lesions (p < 0.05, t test). CONCLUSION: Re- and demineralization characteristics of enamel depended directly on baseline mineral loss and lesion depth. Treatment groups should therefore be well balanced with respect to baseline mineral loss and lesion depth.

Efficacy of sodium and stannous fluoride mouthrinses when used before single and multiple erosive challenges.

BACKGROUND: Application of fluoride mouthrinse before an acidic challenge may decrease enamel erosion. This paper compares the efficacy of stannous (SnF2 ) and sodium (NaF) fluoride when facing single and multiple erosive cycles in vitro. METHODS: Human enamel samples (N = 60) were randomly assigned to groups testing SnF2 and NaF mouthrinses (225 p.p.m.) and a water control. Samples were allocated into subgroups testing one or five erosive cycles. Samples were immersed in test solution for 1 min prior to citric acid immersion (0.3%, pH 3.2, 10 min), and the cycle repeated either one or five times. Analysis was done using profilometry and microhardness change. RESULTS: After one cycle, SnF2 resulted in least step height followed by NaF and water (1.3 µm (0.63), 2.3 µm (0.39), 4.3 µm (0.41) respectively; P < 0.0001). After five cycles SnF2 continued to reduce step height but pre-application of NaF was no different to water (4.6 µm (0.7), 10.5 µm (1.1) and 11.1 µm (0.38) respectively; P < 0.0001). There were no statistical differences in microhardness change between fluorides. After one erosive cycle, fluoride application resulted in statistically softer enamel compared with water. CONCLUSIONS: Both SnF2 and NaF reduced erosion after one cycle. After five cycles, SnF2 continued to offer protection whereas NaF was statistically comparable with water. Softening of enamel may not imply less erosion has occurred.

Effect of mouthrinses with different active agents in the prevention of initial dental erosion.

INTRODUCTION: Hydrochloric acid (HCl) from the gastric juice is the only source of intrinsic acid, which can reach the oral cavity in cases of gastroesophageal reflux or chronic vomiting, enhancing the risk of dental erosion. AIM: Compare the effects of mouthrinses with different active agents in the prevention of initial dental erosion caused by HCl. SUBJECTS AND METHODS: Casein (CAS at 0.2%), sodium hexametaphosphate (HMP at 0.02%), titanium tetrafluoride (TiF4 at 0.34%), and stannous fluoride (SnF2 at 0.87%) were individually added to an experimental mouthrinse. The mouthrinse without additives was used as the negative control (C) and a commercially available mouthrinse for erosion (ELM-Elmex®) as the reference product. Enamel specimens were exposed to human saliva and randomly assigned to 6 experimental groups (n = 8). Specimens were submitted to erosion in HCl for 10 s, followed by to the experimental mouthrinses for 30 s, and artificial saliva for 60 min. This cycle was repeated 3 times. The total amounts of calcium and phosphorus released by the specimens in the 2nd and 3rd erosive challenges were evaluated by atomic emission spectrometry. Statistical analysis used Shapiro-Wilks and Hartley tests, followed by one-way ANOVA and Tukey tests. RESULTS: When compared with C, ELM and HMP presented significantly less calcium in solution, with no difference between them. All the groups showed similar and significantly less phosphorus than C, except CAS. CONCLUSIONS: HMP was the only agent that could match the protection against initial erosion of the commercially available mouthrinse in both analyses.

Biofilm community diversity after exposure to 0·4% stannous fluoride gels.

AIMS: To test the effect of 0·4% stannous fluoride (SnF2 ) glycerine-based gels on specific portions of the bacterial community in both a clinical observational study and in vitro multispecies plaque-derived (MSPD) biofilm model. METHODS AND RESULTS: Potential changes to specific portions of the bacterial community were determined through the Human Oral Microbial Identification Microarray (HOMIM). Both the observational clinical study and the biofilm model showed that short-term use of 0·4% SnF2 gel has little effect on the bacterial community depicted by hierarchical cluster analysis. The amount of plaque accumulation on a subject's teeth, which was measured by plaque index scores, failed to show statistical significant changes over the two baselines or after treatment (P = 0·9928). The in vitro results were similar when examining the effect of 0·4% SnF2 gels on biofilm adherence through a crystal violet assay (P = 0·1157). CONCLUSIONS: The bacteria within the dental biofilms showed resilience in maintaining the overall community diversity after exposure to 0·4% SnF2 topical gels. SIGNIFICANCE AND IMPACT OF THE STUDY: The study supports that the immediate benefits of using 0·4% SnF2 gels in children may be strictly from fluoride ions inhibiting tooth demineralization rather than delivering substantial antimicrobial effects.

The protective effect of SnF2 containing toothpastes and solution on enamel surfaces subjected to erosion and abrasion in situ.

BACKGROUND: Stannous fluoride solutions have shown promising protective effect against erosion/abrasion, but the effect of SnF2 toothpastes is uncertain. AIM: The aim of the study was to test the inhibiting effect of two SnF2 toothpastes and a SnF2 solution against erosive/abrasive wear in a single-blind, randomised in situ study, using a white light interferometer. METHODS: Sixteen human molars were each divided into four specimens, mounted on mouth appliances and worn by 8 volunteers for 9 days. Specimens were brushed with toothpaste twice each day for 30 s either with fluoride-free toothpaste or toothpastes including SnF2. Toothpaste was left on the surface for 90 additional seconds. Group 1, fluoride-free toothpaste; Group 2, toothpaste A (0.4% SnF2, Solidox); Group 3, toothpaste B (0.454 % SnF2, Oral-B(®)); Group 4, brushed with fluoride-free toothpaste (30 s) and treated for 2 min with a 0.4 % SnF2 solution (1,000 ppm F). To mimic gastric reflux/vomit, specimens were etched for 2 min twice a day (0.01 M HCl). Procedures were performed extra-orally. RESULTS: The mean enamel wear (in µm) for the control specimens was: -29.2 ± SD 10.5; for group 2 -14.5 SD ± 9.3; for group 3 -33.3 SD ± 7.4, and for group 4 +0.4 SD ± 1.3. The specimens treated with SnF2 solution and toothpaste A showed significantly lower enamel wear than the control group. Toothpaste B gave no significant reduction in enamel wear. CONCLUSIONS: The SnF2 solution fully protected the enamel surface against erosive and abrasive challenges. The SnF2 toothpaste A (Solidox) showed less, but significant protection of the enamel, while no statistically significant protection was demonstrated by SnF2 toothpaste B (Oral-B(®) Pro-Expert).

Comparative evaluation of diode laser, stannous fluoride gel, and potassium nitrate gel in the treatment of dentinal hypersensitivity.

The aim of the present study was to compare the efficacy of diode laser (DL) with stannous fluoride and potassium nitrate gels in the treatment of dentinal hypersensitivity (DH). Fifty-four subjects, ages 25-45, having 2 adjacent teeth sensitive to air blast stimulation were included. The subjects were divided randomly into 3 groups (n= 18): Group A, subjects treated with DL; Group B, subjects treated with 0.4% stannous fluoride gel; and Group C, subjects treated with 5% potassium nitrate gel. Each group was evaluated at baseline; at weekly intervals for 2 consecutive weeks; and at 1, 3, and 6 months. All 3 groups showed decreases in the DH scores between baseline and 6 months This was more pronounced in Group A at all time intervals. When the 3 groups were compared between baseline and Week 1, there was a statistically significant decrease across all 3 groups between (P = 0.0020). The greatest difference in the DH scores between baseline and Week 1 was in Group A, compared to Groups B and C. The 940 nm DL was not only efficacious, but also brought about improved immediate relief as compared to stannous fluoride and potassium nitrate gels in the reduction of DH.

Randomized controlled trial of 0.454% stannous fluoride dentifrice to treat gingival bleeding.

PURPOSE: To evaluate the effects of a highly bioavailable 0.454% stannous fluoride dentifrice on established gingival bleeding over a 3-month period. MATERIALS AND METHODS: A randomized controlled clinical trial was conducted. In total, 100 adults with mild-to-moderate gingivitis and an average of 15 bleeding sites were assigned to either the stannous fluoride or regular control pastes for at-home use. Of these, 99 received study treatment and 97 completed the study. RESULTS: The stannous fluoride group experienced 50% to 74% reductions in bleeding sites relative to baseline or the control, differing significantly (P < 0.001) at all time points. Most subjects in the stannous fluoride group (94%) had measured improvements in bleeding, and nearly one half completed treatment with one or no bleeding sites. CONCLUSION: These study results suggest that incorporation of this 0.454% stannous fluoride dentifrice into daily oral hygiene maybe expected to yield less gingival bleeding at subsequent dental check-ups, and therefore reduce the risk of progressive periodontal disease.

The anticaries effect of a food extract (shiitake) in a short-term clinical study.

The main objective was to investigate whether low-molecular-weight fraction of edible mushroom shiitake extract (Lentinus edodes) possesses caries-preventive properties. The study was designed as a double-blind, three-leg, cross-over, randomized, controlled clinical trial carried out on two series of volunteers at the University of Gothenburg, and the Academic Centre for Dentistry Amsterdam. Volunteers rinsed twice daily with a solution containing low-molecular-weight fraction of edible mushroom, placebo (negative control without active ingredients), or Meridol (positive control, AmF-SnF(2)) for two weeks, with a two-week washout period between each rinsing period. Changes in the acidogenicity of dental plaque before and after a sucrose challenge, shifts in microbial composition, and plaque scores were determined. Frequent rinses with shiitake reduced the metabolic activity of dental plaque. No reduction of plaque scores and no inhibition of the production of organic acids in plaque was found. Minor differences in microbial composition between test sessions were found. To conclude, the results indicate that shiitake extract has anticariogenic potential, but not to the same extent as the positive control.

Influence of extra- and intra-oral application of CPP-ACP and fluoride on re-hardening of eroded enamel.

OBJECTIVES: This in-situ study aimed to investigate the potential of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) crème and fluoride mouth rinse to re-harden erosively softened enamel and to evaluate the influence of an intra-oral or extra-oral application. METHODS: Ten volunteers performed five experimental series. Per series, four bovine enamel samples were extra-orally softened by immersion in Sprite light(®) (2 min) and subsequently worn intra-orally for 5 min in intra-oral appliances. Thereafter, samples were treated (3 min) with either 250 ppm AmF/SnF(2) solution (Meridol) (series 1 and 3) or CPP-ACP crème (Tooth Mousse) (series 2 and 4). Application of the substances was performed extra-orally (series 1 and 2) or intra-orally (series 3 and 4). Untreated specimens served as control (series 5). The appliances were worn for 4 h afterwards. Knoop microhardness (KHN) measurement was performed at baseline, after softening and after completing of the respective run. Data were statistically analyzed by ANOVA and Bonferroni/Dunn post-hoc test. RESULTS: No significant difference in baseline microhardness was observed, while immersion in Sprite light reduced the microhardness significantly. Significant re-hardening after intra-oral exposure occurred in all series, but baseline microhardness was not achieved. Microhardness in series 2 was significantly higher than that in series 1 and 5. No significant differences in KHN were detected between series 3, 4 and 5. The re-hardening ΔKHN (final microhardness - microhardness after erosion) was not significant different in all five series. CONCLUSION: Intra-oral application of CPP-ACP crème or fluoride solution provides no benefit regarding re-hardening of erosively softened enamel.

A qualitative and quantitative investigation into the effect of fluoride formulations on enamel erosion and erosion-abrasion in vitro.

OBJECTIVES: To investigate the effect of a single application of highly concentrated SnF(2) and NaF solutions and a NaF/CaF(2) varnish on human enamel subjected to hydrochloric acid erosion and tooth brush abrasion. METHODS: Forty enamel samples were prepared from human third molars and NaF (9500ppm, pH 8.0), SnF(2) (9500ppm, pH 2.6) solutions; Bifluorid10(®) varnish (42,500ppm, NaF 5%, CaF(2) 5%) and deionized water (control) was applied to the enamel. Following this three, six and nine cycles of erosion [1 cycle=erosion (0.01M HCl, pH 2.2, 2min)+artificial saliva (1h, pH 7.0)] and erosion-abrasion [1 cycle=erosion (0.01M HCl, pH 2.2, 2min)+artificial saliva (1h, pH 7.0)+abrasion (120 linear strokes in artificial saliva from Tepe medium soft brushes 200g loading)] were carried out. The fluoride treated enamel was analysed using Knoop microhardness, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). RESULTS: For erosion alone, there was significantly less microhardness reduction in the Bifluorid10(®) group after three and six cycles of erosion (P<0.05), however no other groups showed statistically different hardness (P>0.05). The EDS analysis showed that only the Bifluorid10(®) group had any detectable fluorine following erosion and erosion-abrasion (0.1wt.% and 0.2wt.% fluorine respectively). The surface fluorine was found to have been removed after erosion and erosion-abrasion for all other surface treatments. Although precipitates were observed after application of the surface treatments, following erosion-abrasion, no visible surface effects from any fluoride preparation remained. CONCLUSIONS: Enamel surface precipitates from application NaF, SnF(2) solutions appear to not be able to provide protection against gastric erosion and tooth brush abrasion. The NaF/CaF(2) varnish provided limited protection against erosion but the role for such varnishes in gastric erosion and tooth brush abrasion remains uncertain.

Antimicrobial efficacy of oral topical agents on microorganisms associated with radiated head and neck cancer patients: an in vitro study.

OBJECTIVE: A variety of oral topical agents have been used for prevention and management of radiotherapy-induced adverse effects. The antimicrobial nature of some of the commonly used agents is unknown. The purpose of this study was to evaluate antimicrobial efficacies of various oral topical agents on common microorganisms associated with radiated head and neck cancer patients. METHOD AND MATERIALS: Seven commonly used topical oral agents-0.12% chlorhexidine with alcohol, 0.12% chlorhexidine without alcohol, baking soda-salt rinse, 0.4% stannous fluoride gel, 0.63% stannous fluoride rinse, calcium phosphate mouthrinse, and acemannan hydrogel (aloe vera) rinse-were evaluated in vitro for their antimicrobial efficacies against four common microorganisms. A combination of baking soda-salt rinse and 0.4% stannous fluoride gel was evaluated as the eighth agent. The microorganisms used were Staphylococcus aureus, group B Streptococcus, Escherichia coli, and Candida albicans. An ELISA reader was used to measure the turbidity of microbial culture wells and optical density (OD) values for each of the 960 wells recorded. Mean OD values were rank ordered based on their turbidity. One-way ANOVA with Tukey HSD post hoc analysis was used to study differences in OD values (P < .05). RESULTS: Mean OD values classified for topical agents from lowest to highest were chlorhexidine with alcohol, chlorhexidine without alcohol, baking soda- salt, calcium phosphate rinse, and the combination of baking soda-salt and stannous fluoride gel. Mean OD values classified for microorganisms from lowest to highest were Escherichia coli, Staphylococcus aureus, group B Streptococcus, and Candida albicans. CONCLUSION: A significant difference among the antimicrobial efficacies of topical agents was evident for each of four microorganisms (P < .05). There was also a significant difference among the antimicrobial efficacies of the same topical agent on the four microorganisms tested (P < .05).