Subgingival uptake and retention of stannous fluoride from dentifrice: Gingival crevicular fluid concentrations in sulci post-brushing.

PURPOSE: To examine the delivery of stannous fluoride to subgingival sulci following toothpaste use in a clinical population. METHODS: This was a controlled, single-site study. 23 subjects with at least 20 dental pockets, 2-4 mm with bleeding, who had not used a stannous fluoride dentifrice in the last 3 months were enrolled. After a 2-week washout period, 20 subjects returned for a baseline visit. They were instructed to refrain from brushing the night before the baseline visit. GCF samples were taken from up to 10 sites identified as sampling sites. Subjects were then given a 0.454% stannous fluoride dentifrice and soft manual toothbrush and asked to brush for 1 minute. 30 minutes after brushing, GCF was re-sampled. Subjects continued using the stannous fluoride dentifrice and soft manual toothbrush at home, twice daily for 2 weeks, in place of their usual hygiene products. At Days 1 and 14, subjects returned to the site, and 12 hours post-brushing GCF samples were taken. The samples were analyzed by ICP-MS (inductively coupled plasma mass spectrometry). A Wilcoxon signed-rank test was performed to determine the difference between post-baseline visits and baseline. Statistical tests were 2-sided using a 5% significance level. RESULTS: 20 subjects completed the trial. Significant levels of tin, a marker for stannous fluoride, were detected 30 minutes after brushing at sampling sites of 2-4 mm. The median tin level in gingival crevicular fluid (GCF) was 24.59 ng/µl, which was highly significant versus baseline (P< 0.0001). Tin levels sampled in GCF 12 hours after brushing on Days 1 and 14 were highly significant versus Baseline (P< 0.0001), showing an increasing trend with continued use. CLINICAL SIGNIFICANCE: Stannous fluoride was found to penetrate sampling sites from 2-4 mm and was retained for 12 hours. Subgingival uptake and retention of stannous fluoride following toothbrushing may play a role in detoxification effects on microbial biofilms and may contribute to the therapeutic efficacy of stannous fluoride dentifrices in promoting gingival health.

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.

Comparative bioavailability and antimicrobial activity of cetylpyridinium chloride mouthrinses in vitro and in vivo.

PURPOSE: Commercialized cetylpyridinium chloride (CPC) mouthrinses were compared for antimicrobial substantivity/bioavailability in an in vitro disk retention assay (DRA) and clinical antimicrobial activity in vivo in the plaque glycolysis and regrowth method (PGRM). METHODS: Formulations compared in this testing included commercially available CPC mouthrinses: Crest Pro Health (CPH), (containing 700 ppm formulated CPC); Colgate Total Puerto Rico (CT450), (containing 450 ppm formulated CPC); Colgate Total US (CT750), (containing 750 ppm formulated CPC); and Scope Mouthwash (SCP), (containing 450 ppm formulated CPC). A water control (CTR) was included in one of the PGRM clinical trials. Two separate clinical PGRM studies employed a controlled, double-blind, randomized, crossover design where qualified adult PGRM panelists were supplied with acclimation NaF dentifrice for use throughout the trials. On treatment days, subjects sampled baseline plaque and then rinsed with assigned mouthrinse following morning toothbrushing. Treated plaque samples were collected 15 and 45 minutes after rinsing. Sampled plaques were vortexed, normalized for biomass and incubated under standard conditions to assess glycolysis. pH response of treated plaques in incubation buffers were compared to baseline untreated plaque values and an Area Under Curve (AUC) composite/aggregate analysis of glycolysis inhibition was used for treatment comparisons. A laboratory disk retention substantivity/bioavailability assay measured adsorption affinity of CPC in mouthrinse for anionic cellulose disks in vitro. RESULTS: Clinical PGRM studies showed significant differences in antibacterial clinical efficacy of commercialized mouthrinses. Combining clinical study results reveals rank ordered efficacy CPH > CT750 > SCP > CT450 > CTR. Comparison of DRA to PGRM glycolysis showed a linear relation highlighting correlation of CPC bioavailability to clinical antimicrobial performance of CPC mouthrinses.

The effects of high concentration tooth whitening bleaches on microleakage of Class V composite restorations.

OBJECTIVE: To explore the effects of high-concentration hydrogen peroxide bleaching agents on the microleakage of composite restorations. METHODS: In 60 extracted human molars, Class V restorations were prepared with Scotchbond 1/Filtek Z250 composite. Teeth were randomly divided into four groups: (1) no bleaching; (2) bleaching with 14% hydrogen peroxide gel from Crest Whitestrips; (3) bleaching with 20% carbamide peroxide gel from Opalescence PF 20; and (4) bleaching with 38% hydrogen peroxide gel Opalescence Xtra Boost. Bleaching procedures were carried out at 37 degrees C for 21 days/42 hours (2); seven days/42 hours (3); one day/45 minutes (4). Varnish was applied on the apical portion of the teeth only, excluding the restoration, prior to immersion in a 0.1% rhodamin-B-isothiocyanate solution for 24 hours at 37 degrees C. After rinsing, specimens were embedded in methacrylate blocks, and sectioned with a water-cooled microtome with three restoration cuts positioned centrally parallel to the long axis of the tooth. Microleakage was evaluated at the occlusal margins of the Class V restorations using a stereo microscope, separate for dentin and enamel margins. RESULTS: Over 90% of enamel margins exhibited no microleakage following cycling. Bleaching agents had almost no effect on numerical averages. Eighty-eight percent of the dentin margins were free of microleakage for the non-treated control group. Bleaching treatments collectively had slight numerical reductions to around 80%. The statistical evaluation (Kruskal-Wallis-test) showed no significant difference in microleakage between groups for enamel or dentin. CONCLUSION: Bleaching with the materials tested had no influence on microleakage of Filtek Z250 composite bonded with Scotchbond 1.

Effects of elevated hydrogen peroxide 'strip' bleaching on surface and subsurface enamel including subsurface histomorphology, micro-chemical composition and fluorescence changes.

OBJECTIVES: This study examined the effects of elevated concentration hydrogen peroxide tooth whitening treatments on tooth surface and subsurface integrity. METHODS: Sound human molars were ground and polished to prepare an uniform substrate for bleaching treatments. A cycling treatment included alternating ex vivo human salivary exposures with bleaching treatments under conditions of controlled temperature and durations of treatment. Bleaching was carried out with prototype bleaching strips containing hydrogen peroxide gel at 13% and 16% concentrations. A non-bleached group was used as a control. Treatments included 28h of total bleaching exposure in vitro. Surface color was measured prior to and following bleaching. Effects of bleach on physical properties of tooth surfaces were assessed by microhardness measures on enamel. Ultrastructural effects were examined by surface and subsurface confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) techniques. In addition, the effects of bleaching on tooth micro-chemical composition were studied by Raman spectroscopy combined with CLSM technique. RESULTS: Color assessments confirmed significant ex vivo tooth bleaching. Surface microhardness and VP-SEM (variable pressure SEM) measures revealed no deleterious effects on the enamel surfaces. CLSM micromorphological assessments supported the safety of hydrogen peroxide bleaching strips both on surface and subsurface enamel, DEJ and dentin ultrastructure. Raman spectroscopy analysis demonstrated no obvious effects of bleaching treatments on the micro-chemical composition of enamel and dentin. Significant effects of bleaching were seen in reducing background luminescence of Raman spectra obtained from enamel and dentin. CONCLUSIONS: These results confirm that hydrogen peroxide whitening strips do not produce changes in surface/subsurface histomorphology, surface microhardness and micro-chemical composition of teeth. Effects of bleaches on tooth luminescence recorded in micro-Raman spectroscopy may serve as an internal signature to bleaching effects and warrant further study.

Physical, morphological, and micro-Raman chemical studies on bleaching strip effects on enamel, coronal dentin, and root dentin.

OBJECTIVE: This study examined the effects of elevated-concentration hydrogen peroxide tooth whitening strips on the surface and subsurface integrity of enamel, coronal dentin, and root dentin. METHODOLOGY: Sound human teeth were ground and polished to prepare a uniform substrate for bleaching. A cycling regimen included exposures to saliva, bleaching treatments, and fluoridated toothpaste. Bleaching was carried out with plastic strips containing hydrogen peroxide gel at 11.7 and 14% concentrations. A non-bleached group served as a control. Bleaching times measured up to 45 hours. Physical properties of tooth surfaces were assessed by microhardness, while surface morphological properties of teeth were examined by profilometry, surface Confocal Laser Scanning Microscopy (CLSM), and Variable Pressure Scanning Electron Microscopy (VP-SEM). Subsurface histomorphological effects on teeth were assessed by CLSM. Lastly, the influences of bleaching on tooth micro-chemical composition was studied by micro-Raman spectroscopy using a unique spectrometer in line, coupled to the CLSM via glass fiber. RESULTS: Surface microhardness, profilometry, CLSM, and VP-SEM measures showed enamel and root dentin surfaces were unchanged with bleaching. CLSM micromorphological assessments demonstrated normal histology for bleached teeth on surface and subsurface enamel, DEJ, and dentin. Raman spectroscopy demonstrated no effects of bleaching treatments on the microchemical mineral composition of enamel and dentin. Bleaching treatments were observed to reduce background luminescence of enamel, DEJ, and dentin. CONCLUSION: These results confirm that whitening strips delivering controlled doses of hydrogen peroxide at 11.7 and 14% concentrations do not produce changes in surface/subsurface histomorphology, surface microhardness, or micro-chemical mineral composition of teeth. The effects of bleaches on tooth luminescence recorded in micro-Raman spectroscopy may serve as an internal signature to bleaching effects and warrant further study.