Highly Pathogenic Avian Influenza Virus A(H5N1) Clade 2.3.4.4b Infection in Free-Ranging Polar Bear, Alaska, USA.

We report a natural infection with a Eurasian highly pathogenic avian influenza A(H5N1) clade 2.3.4.4b virus in a free-ranging juvenile polar bear (Ursus maritimus) found dead in North Slope Borough, Alaska, USA. Continued community and hunter-based participation in wildlife health surveillance is key to detecting emerging pathogens in the Arctic.

Highly Pathogenic Avian Influenza A(H5N1) Virus Clade 2.3.4.4b Infections in Wild Terrestrial Mammals, United States, 2022.

We describe the pathology of natural infection with highly pathogenic avian influenza A(H5N1) virus of Eurasian lineage Goose/Guangdong clade 2.3.4.4b in 67 wild terrestrial mammals throughout the United States during April 1‒July 21, 2022. Affected mammals include 50 red foxes (Vulpes vulpes), 6 striped skunks (Mephitis mephitis), 4 raccoons (Procyon lotor), 2 bobcats (Lynx rufus), 2 Virginia opossums (Didelphis virginiana), 1 coyote (Canis latrans), 1 fisher (Pekania pennanti), and 1 gray fox (Urocyon cinereoargenteus). Infected mammals showed primarily neurologic signs. Necrotizing meningoencephalitis, interstitial pneumonia, and myocardial necrosis were the most common lesions; however, species variations in lesion distribution were observed. Genotype analysis of sequences from 48 animals indicates that these cases represent spillover infections from wild birds.

A randomized, controlled, two-month pilot trial of stannous fluoride dentifrice versus sodium fluoride dentifrice after oxalate treatment for dentinal hypersensitivity.

OBJECTIVES: To compare the effects of a stannous fluoride dentifrice and a sodium fluoride dentifrice on dentinal hypersensitivity when used with an oxalate-based regimen combining in-office and at-home treatment. MATERIALS AND METHODS: In this single-center, randomized, controlled, double-blind, pilot clinical trial, 30 subjects were professionally treated at baseline with a 3% oxalate/potassium salt solution on up to two target teeth, then randomized 1:1 to either 0.454% stannous fluoride or 0.243% sodium fluoride overlabeled dentifrice. Both groups were given 6 sensitivity strips (3.14% potassium oxalate gel) and a soft, manual toothbrush. Subjects were permitted to apply strips on up to two teeth, up to three times per tooth, at home as desired throughout the study. Dentinal sensitivity (cold air blast challenge) was assessed at baseline, immediately after post-professional treatment, and at day 60 using the Schiff scale and a Visual Analog Scale (VAS). RESULTS: Immediately after professional oxalate treatment, the overall mean Schiff and VAS score decreased 25.6% and 22.4% from baseline, respectively (p ≤ 0.001 for both). At day 60, further reductions in both mean scores were seen in both groups. There were no significant differences between the groups at day 60. All treatments were well tolerated. CONCLUSIONS: In subjects treated with oxalates for dentinal hypersensitivity, both stannous fluoride and sodium fluoride dentifrices are well tolerated, are feasible for routine use, and do not detract from the desensitizing effects of an in-office and at-home oxalate combination treatment regimen. CLINICAL RELEVANCE: Either stannous fluoride or sodium fluoride dentifrices can be recommended to dentinal hypersensitivity patients who undergo professional oxalate treatment.

Ecological drivers of mercury concentrations in fish species in subsistence harvests from Kotzebue Sound, Alaska.

The State of Alaska assesses human exposure to mercury (Hg) via fish consumption producing consumption guidelines for fish tailored for children and women of childbearing age. Under these guidelines, unrestricted consumption is suggested for many fish species, while limited consumption is recommended for others. Subsequent questions have arisen regarding ecological drivers influencing [Hg] in fishes consumed by Alaskans. This community-assisted public health study evaluates [Hg] in fishes from Kotzebue Sound to examine factors that may drive observed [Hg]. We examined eight species of subsistence harvested fish (least cisco, chum salmon, Pacific herring, humpback whitefish, sheefish, starry flounder, Pacific tomcod, and fourhorn sculpin) from Kotzebue Sound. We report total Hg concentrations ([THg]) and monomethyl Hg+ concentrations ([MeHg+]) in the context of various factors (such as species, fork length, carbon and nitrogen stable isotope (δ15N or δ13C)) values that may influence [Hg] and [MeHg+]. Across all 297 fish, [THg] ranged from 3.4 - 235.2 ng/g ww. [THg] was positively correlated with fork length in six of eight fish species, as well as with trophic level (indicated by δ15N values) in five species. [MeHg+] was positively correlated with fork length in four species, and with δ15N values over all specimens examined, and specifically for three individual species. In six of the seven species analyzed, %MeHg was >80% of [THg]. This value decreased with fork length in three species, with no relationship for δ15N values in any species. Among top ranked models based on Akaike Information Criterion correction (AICc), fork length was more frequently included as an explanatory factor for [Hg] than δ15N or δ13C values. The food web magnification factor for [THg] was 11.3, and 12.6 for [MeHg+]. Biomagnification is likely driving [THg] and [MeHg+] over the entire food web, while within species, bioaccumulation is likely a stronger driver of [THg] and [MeHg+] than feeding ecology or trophic position. The [THg] for all species fell within the established unrestricted consumption guideline of 200 ng/g weight wet as established by the State of Alaska's fish consumption guidelines for Hg.

Mycoplasma ovipneumoniae in Wildlife Species beyond Subfamily Caprinae.

Elucidating the emergence of Mycoplasma ovipneumoniae-associated respiratory disease in ruminants requires identification of the pathogen host range. This bacterium was thought to be host restricted to subfamily Caprinae, but we describe its identification in healthy moose, caribou, and mule deer and diseased mule and white-tailed deer, all species in subfamily Capreolinae.

Clinical evidence on a unique two-step stannous fluoride dentifrice and whitening gel sequence.

PURPOSE: Recently, a unique two-step product was introduced that includes sequential use of a novel 0.454% stannous fluoride dentifrice followed by a 3% hydrogen peroxide whitening gel. The technology targeted advanced gingival health benefits plus esthetic benefits such as tooth whitening. The two-step sequence has unique brushing instructions to maximize the efficacy of each step; the stannous fluoride dentifrice is used for 1 minute of brushing followed by 1 minute of brushing with the hydrogen peroxide gel. This two-step sequence has been studied in numerous clinical trials over a series of years. This comprehensive program included different populations and sites, endpoints and time points, with responses measured versus different positive and negative research controls. A total of six clinical trials are reported herein. Outcomes from this research program demonstrate the significant gingival health efficacy of the two-step product, providing therapeutic efficacy comparable to chlorhexidine, and its positive impact on plaque, tooth stain and breath odor. CLINICAL SIGNIFICANCE: This unique dentifrice/gel sequence delivers a combination of advanced gingivitis efficacy with significant stain reduction - benefits that will positively impact oral health as well as patient compliance.

Safety and effectiveness of a two-step dentifrice/gel sequence with medication-associated hyposalivation: A randomized controlled trial in a vulnerable population.

PURPOSE: A randomized controlled trial was conducted to evaluate the safety and effectiveness of a two-step dentifrice/gel oral hygiene sequence in a vulnerable population. METHODS: Prior to the research, institutional review was obtained for the protocol, consent and advertising. The study targeted adults with medication-associated xerostomia, because of the plaque accumulation and possible oral safety risks seen in this population. Eligible subjects with a medication history and measured hyposalivation were randomly assigned to one of two oral hygiene groups:(1) a two-step 0.454% SnF2 dentifrice and 3% H2O2 gel sequence or (2) a regular anticavity toothpaste control. Test products were dispensed with a regular manual brush in blinded over-labeled kits with usage instructions. Subjects were evaluated at baseline and after 2 and 6 weeks of test product use. Safety was assessed as adverse events from clinical examination and interview. Digital plaque image analysis of the anterior facial teeth measured fluorescein-disclosed daytime plaque levels, and unstimulated saliva was collected over a 5-minute period in pre-weighed vials. RESULTS: A total of 49 subjects ranging from 31-80 years of age (53% female) were enrolled, and 45 completed Week 6. Only the two-step dentifrice and gel sequence differed significantly (P< 0.005) from baseline on daytime plaque coverage, and salivary flow increased significantly (P= 0.033) in that group as well. Between-group comparisons for daytime plaque favored the two-step sequence with 41-46% improvements in plaque control. At Week 6, adjusted daytime plaque means (SE) were 5.9 (0.7) and 10.0 (1.1) for the two-step and control groups, respectively (P< 0.004). Adverse events were mild in severity, groups differed significantly (P= 0.02) on occurrence, and events did not contribute to dropout. CLINICAL SIGNIFICANCE: In a randomized controlled trial among a vulnerable population, use of an oral hygiene sequence comprised of stannous fluoride dentifrice and a hydrogen peroxide whitening gel improved daily plaque control without adversely impacting salivary flow or oral health.

Randomized controlled trial evaluating concurrent gingivitis and stain effects of a two-step dentifrice/gel sequence.

PURPOSE: A randomized controlled trial was conducted to evaluate the clinical efficacy of a two-step dentifrice/whitening gel oral hygiene sequence on natural gingivitis and extrinsic stain. METHODS: The population consisted of healthy adults with clinical evidence of gingivitis and extrinsic stain. Consent, demographic information and clinical measurements were collected, after which subjects were randomized to treatment. Eligible subjects were dispensed blinded test kits containing over-labeled two-step 0.454% SnF2 dentifrice then 3% H2O2 whitening gel sequence or a regular 0.76% NaMFP dentifrice control (Colgate Cavity Protection), plus a regular soft manual toothbrush and instructions for use. Efficacy was assessed blind-to-treatment using the Gingivitis Bleeding Index (GBI) measured whole-mouth and the composite Lobene Stain Index (LSI) measured on the anterior dentition. Treatments were compared at Week 1 and Week 3 versus baseline for ΔGBI and ΔLSI using a two-sided 5% level of significance. RESULTS: A total of 61 subjects with a mean (SD) age of 33.4 (12.0) years were enrolled. Overall baseline means (SD) were 0.16 (0.05) for GBI and 1.30 (0.94) for LSI. After 1 week, only the two-step 0.454% SnF2 dentifrice then 3% H2 O2 whitening gel sequence demonstrated significant (P< 0.0001) reductions in both gingivitis and stain. Adjusted means for the changes with the dentifrice/gel sequence and control were -0.055 and -0.001 for ΔGBI, and -0.619 and -0.095 for ΔLSI, with groups differing significantly (P< 0.0001) on gingivitis and stain improvement. Outcomes at Week 3 were generally similar, with groups differing on bleeding and stain. Treatments were generally well-tolerated. CLINICAL SIGNIFICANCE: In a randomized controlled trial, use of a two-step 0.454% SnF2 dentifrice then 3% H2 O2 whitening gel sequence yielded concurrent improvements in gingivitis and stain compared to regular oral hygiene.

Initial evidence of two-step dentifrice/gel sequence effects on health: Outcomes from three randomized controlled trials.

PURPOSE: Health-related outcomes from three randomized controlled trials represented the initial research on the feasibility of novel, sequential oral hygiene with a stannous fluoride (SnF2) dentifrice then hydrogen peroxide (H2O2) whitening gel. METHODS: One crossover and two parallel clinical trials were conducted independently. Objectives varied, with individual studies assessing short, intermediate or longer-term outcomes from breath, dental plaque or gingivitis, respectively. Treatments were randomly assigned, and blinded test kits were dispensed containing either: 1) a two-step 0.454% SnF2 dentifrice and then a 3% H2O2 whitening gel sequence and instructions specifying 1+1 minute sequential brushing (experimental); or 2) 0.76% sodium monofluorophosphate dentifrice (Colgate Cavity Protection) and instructions for twice daily use (control). Standard methods were used to measure efficacy (volatile sulfur compounds, plaque area coverage or gingival bleeding) and safety (clinical examination and interview), and to compare treatment responses. RESULTS: Overall, 165 subjects participated in the three trials. Relative to baseline, only the experimental group exhibited significant (P< 0.05) improvements at initial and subsequent timepoints in each trial. Between-group comparisons showed significant (P< 0.05) 30-45% reductions in breath malodor (VSC), plaque (area%) and gingivitis (bleeding sites) favoring the experimental group. Adverse event occurrences were infrequent, mild in severity, and unrelated to dropout. CLINICAL SIGNIFICANCE: Important health-related outcomes from three initial clinical trials established the feasibility of sequential brushing with a two-step 0.454% SnF2 dentifrice and then a 3% H2O2 whitening gel.

A randomized, controlled comparison of two professional dentin desensitizing agents immediately post-treatment and 2 months post-treatment.

PURPOSE: To compare the desensitizing effects of two different marketed professional dentin hypersensitivity treatments, a 5% sodium fluoride varnish and an oxalic acid/potassium salt solution, in a single-center, randomized, controlled, subject-blind pilot study. METHODS: A total of 22 subjects with dentin hypersensitivity on at least two teeth were recruited from a general dentistry practice and randomized 1:1 to treatment with a 5% sodium fluoride varnish (Acclean Fluoride Varnish) group or a 3% oxalic acid/potassium salt solution (Super Seal Desensitizer). The study population was predominantly female (91%) and Caucasian (77%). The mean age was 46.4 years, with ages ranging from 18-73 years. Dentin hypersensitivity was assessed after an air blast challenge by the examiner (Schiff Index Sensitivity Scale) and by the subject [Visual Analog Scale (VAS)] for each tooth tested. Hypersensitivity was assessed immediately post-treatment and at 2 months post-treatment. RESULTS: For the sodium fluoride varnish group, the mean Schiff score decreased 61% from baseline immediately post-treatment (P= 0.0006) and 41% at Month 2 (P= 0.0069). For the oxalic acid/potassium salt solution group, the mean Schiff score decreased 33% from baseline immediately post-treatment (P= 0.0305) and 29% at Month 2. Similarly, the mean VAS scores in the sodium fluoride varnish group decreased 41% from baseline immediately post-treatment (P= 0.0030) and 34% at Month 2 (P= 0.0275). The mean VAS scores in the oxalic acid/potassium salt solution group decreased 35% from baseline immediately post-treatment (P= 0.0168) and 33% at Month 2 (P= 0.0283). An analysis of covariance found no statistically significant between-group differences in mean Schiff scores or VAS scores immediately post-treatment or at Month 2. Both treatments were well tolerated. There were no reported adverse events in either treatment group. CLINICAL SIGNIFICANCE: Both 5% sodium fluoride varnish and an oxalic acid/potassium salt solution are safe and effective options to treat dentin sensitivity in otherwise healthy adults. The examiner-rated Schiff scores and the patient-rated VAS scores consistently demonstrated a reduction in sensitivity with either treatment, both immediately after professional application and at 2 months post-treatment.

Post-prophylaxis gingivitis prevention with two-step stannous fluoride dentifrice plus whitening gel sequence or chlorhexidine gluconate mouthrinse.

PURPOSE: To assess use of a two-step dentifrice/gel sequence versus chlorhexidine gluconate mouthrinse on gingivitis prevention after dental prophylaxis. METHODS: A 12-week, randomized controlled trial was conducted to compare the effectiveness and safety of a two-step dentifrice/gel sequence to a positive control in healthy adults with established gingivitis. After informed consent, gingivitis and stain levels were assessed by clinical examination. Eligible subjects received a dental prophylaxis and were randomly assigned to twice daily unsupervised use of either (1) two-step oral hygiene sequence:0.454% stannous fluoride dentifrice followed by 3.0% hydrogen peroxide whitening gel for the test group; or (2) 0.12% chlorhexidine gluconate oral rinse and 0.76% sodium monofluorophosphate dentifrice for the control group. Clinical measurements of gingivitis bleeding sites and tooth stain area/intensity were collected after 4, 8 and 12 weeks use, while safety was assessed via clinical examination and oral status interview of the subjects. RESULTS: A total of 44 subjects were enrolled and 35 completed the 12-week study. At baseline, bleeding sites ranged from 10-33. After prophylaxis and assigned treatment, both groups exhibited significant (P≤ 0.0001) reductions in bleeding sites. Responses were directionally better in the two-step sequence at all post-baseline timepoints, with groups differing significantly (P < 0.05) at Week 8. Tooth stain measurements demonstrated that the two-step dentifrice/gel sequence did not contribute to any significant (P> 0.13) stain accumulation. In contrast, stain accumulation was evident (P< 0.003) in the chlorhexidine group beginning at the Week 4 visit. Adverse events were more common in the positive control, and contributed to early termination. CLINICAL SIGNIFICANCE: Twice daily use of a two-step stannous fluoride dentifrice and peroxide whitening gel sequence after prophylaxis provided comparable or superior gingivitis benefits to chlorhexidine gluconate rinse without the concomitant side effect of staining.

A Randomized Controlled Clinical Trial to Evaluate the Efficacy of an Oscillating-Rotating Electric Toothbrush, a Stannous Fluoride Dentifrice, and Floss on Gingivitis.

OBJECTIVES: To evaluate the gingival health efficacy of an oscillating-rotating electric toothbrush, a stannous fluoride dentifrice, and dental floss in adults with mild-to-moderate gingivitis. METHODS: This was a single-center, randomized, controlled, examiner-blind, two-treatment, eight-week parallel group study in adults with at least 20 gingival bleeding sites. Eligible subjects were randomized equally to one of two groups: experimental oral hygiene group that included an Oral-B® oscillating-rotating electric toothbrush with round brush head (D20/EB20), Crest® stabilized stannous fluoride dentifrice (SnF2 1100 ppm F, NaF 350 ppm F), and Oral-B® Glide® floss; or regular oral hygiene control group that included a regular manual toothbrush (Oral-B® Indicator 35) and Crest® anti-cavity sodium fluoride dentifrice (NaF 1450 ppm F). Subjects followed manufacturer's instructions and used their assigned products over an eight-week period. Gingival health was measured at baseline, Week 4, and Week 8 using three assessments: Gingival Bleeding Index (GBI), number of bleeding sites, and Modified Gingival Index (MGI). Analysis of Covariance was used to compare gingival health between treatment groups. RESULTS: One hundred and twenty subjects, mean age 44 years (range: 21 to 74 years), were assessed at baseline (60 per group); 113 subjects (57 in control group, 56 in experimental group) completed the study with fully evaluable data. At baseline, the groups were balanced; overall means were 0.41 for GBI, 51.7 for bleeding sites, and 1.44 for MGI. Only the experimental group showed statistically significant reductions from baseline (p < 0.0001) for all three gingivitis assessments at both Weeks 4 and 8. At these time points, better gingival health for the experimental group was seen as significantly lower adjusted mean scores versus the control group (p < 0.0001) for all three assessments. Reductions in favor of the experimental group at Weeks 4 and 8, respectively, were 51% and 45% for GBI, 46% and 40% for number of bleeding sites, and 37% and 20% for MGI. The study treatments were well tolerated. CONCLUSIONS: Over an eight-week period, an oral hygiene routine with an oscillating-rotating electric toothbrush, stannous fluoride dentifrice, and floss significantly improved gingivitis compared to regular hygiene with a manual toothbrush and an anti-cavity sodium fluoride dentifrice.

Treatment responses to tooth whitening in twins.

The aim of this study was to determine heritability estimates of treatment responses to a 10% hydrogen peroxide strip-based whitening system in twins. Eighty-five twin pairs were randomly assigned to 10% hydrogen peroxide whitening strips or placebo strips without peroxide. Both twins (monozygotic or dizygotic) received the same treatment. Maxillary teeth were treated for 30 minutes twice daily for 7 days. Efficacy was measured objectively as L* (light-dark), a* (red-green), and b* (yellow-blue) color change from digital images at baseline (∆) and day 8. Heritability estimates for tooth whitening treatment responses for changes from day 8 to baseline were obtained using variance-component methodologies. Whitening treatment responses were highly heritable (h(2) = 71.0) for ∆b* and ∆a*(p < .0001), but not for ∆L* (h(2) = 27.0), which was essentially modulated by environmental factors. This study has demonstrated that both genetic and environmental factors significantly contributed to seven-day whitening treatment responses achieved with 10% hydrogen peroxide strips.

Placebo-controlled clinical trial evaluating 9.5% hydrogen peroxide high-adhesion whitening strips.

OBJECTIVE: To evaluate the effectiveness and tolerability of an experimental 9.5% hydrogen peroxide whitening strip relative to a placebo control over a three-week period. METHODS: In this parallel-design, double-blind clinical trial, 54 adult volunteers were randomized to an experimental 9.5% hydrogen peroxide whitening strip or placebo strip balancing for age and baseline tooth color, and received treatment. Strips were worn on the maxillary arch 30 minutes daily for 20 days. Efficacy was measured objectively as L*a*b* color change from digital images at Days 4, 7, 15, and 21. RESULTS: As early as Day 4 and at all subsequent visits, the 9.5% strip group experienced significant (p < 0.004) color improvement relative to placebo for b* and L* color parameters. The amount of color improvement increased with continuing peroxide strip use. Mean ± SE between-group differences in Ab* were -0.6 ± 0.16, -0.8 ± 0.15, -1.6 ± 0.19, and -1.9 ± 0.20 at Days 4, 7, 15, and 21, respectively. Similar results were noted for AL*. Minor tooth sensitivity was the most common adverse event, as reported by 12% of subjects in the 9.5% strip group and 11% of subjects in the placebo group. No subjects discontinued treatment due to an adverse event. CONCLUSION: This placebo-controlled clinical trial demonstrated that an experimental 9.5% hydrogen peroxide strip yielded significant tooth whitening relative to a placebo strip as early as after three days of product use.

Ticks and tick-borne microbes identified through passive and active surveillance in Alaska.

Rapid environmental change in Alaska and other regions of the Arctic and sub-Arctic has raised concerns about increasing human exposure to ticks and the pathogens they carry. We tested a sample of ticks collected through a combination of passive and active surveillance from humans, domestic animals, and wildlife hosts in Alaska for a panel of the most common tick-borne pathogens in the contiguous United States to characterize the diversity of microbes present in this region. We tested 189 pooled tick samples collected in 2019-2020 for Borrelia spp., Anaplasma spp., Ehrlichia spp., and Babesia spp. using a multiplex PCR amplicon sequencing assay. We found established populations of Ixodes angustus Neumann (Acari: Ixodidae), Ixodes uriae White (Acari: Ixodidae), and Haemaphysalis leporispalustris Packard (Acari: Ixodidae) in Alaska, with I. angustus found on a variety of hosts including domestic companion animals (dogs and cats), small wild mammals, and humans. Ixodes angustus were active from April through October with peaks in adult and nymphal activity observed in summer months (mainly July). Although no known human pathogens were detected, Babesia microti-like parasites and candidatus Ehrlichia khabarensis were identified in ticks and small mammals. The only human pathogen detected (B. burgdorferi s.s.) was found in a tick associated with a dog that had recently traveled to New York, where Lyme disease is endemic. This study highlights the value of a combined passive and active tick surveillance system to detect introduced tick species and pathogens and to assess which tick species and microbes are locally established.

Evaluation of an advanced oral hygiene regimen on maternity outcomes in a randomized multicenter clinical trial (Oral Hygiene and Maternity Outcomes Multicenter Study).

BACKGROUND: During pregnancy, dental plaque-induced gingivitis prevalence and subsequent risk of periodontal disease increases substantially, as a consequence of both inadequate oral hygiene and changes in sex steroid hormone levels. Although maternal periodontal disease has been associated with adverse pregnancy outcomes, including spontaneous preterm birth, previous clinical trials involving mechanical debridement (eg, scaling and root planing) to remove plaque biofilm have not yielded decreased rates of preterm birth. OBJECTIVE: We hypothesized that an advanced oral hygiene program, including an antibacterial regimen coupled with a power toothbrush and hygiene instruction, may improve the periodontal milieu and reduce the rate of spontaneous preterm birth. Therefore, we conducted a clinical trial of obstetrical patients with moderate-to-severe gingivitis who were randomized to an advanced oral hygiene program vs usual oral hygiene care, and the primary obstetrical outcome compared between the treatment groups was gestational age at delivery. STUDY DESIGN: Obstetrical patients with singleton pregnancies between 8 and 24 weeks' gestation were screened by trained dentists at 2 clinical sites for moderate-to-severe gingivitis (>30 intraoral sites with gingival bleeding on probing). Eligible participants were randomized to an advanced oral hygiene regimen, including antibacterial mouth wash, dental floss, antibacterial toothpaste, a power toothbrush, and intensive oral hygiene education vs standard oral home care instructions and regimen. The primary obstetrical outcome assessed was gestational age at delivery. The overall primary (dental) outcomes were gingival index, bleeding sites, and pocket depth (reported elsewhere). Secondary obstetrical outcomes included birthweight and incidence of preterm birth at <37 weeks' gestation. Regression models were utilized and included factors such as treatment group, gestational age at enrollment, preterm birth history, and potential markers of health disparities (ie, education, employment status). RESULTS: A total of 817 obstetrical patients underwent dental screening at the 2 sites, 789 were identified with moderate-to-severe gingivitis, 746 were randomized, and birth outcomes were available for 613 of the study participants. The gestational age at delivery was 2 days earlier in the control group (P=.040), but the clinical significance of this finding was limited (39.13 vs 38.85 weeks). Overall rates of spontaneous preterm birth <37 weeks and <34 weeks were not statistically different between the 2 treatment groups (7.0% advanced oral hygiene regimen vs 10.3% controls, OR=1.63 (0.90-3.00), P=.11; and 2.3% vs 3.9%, OR=1.88 (0.71-4.98), P=.20, respectively). However, we observed lower rates of spontaneous preterm birth among unemployed participants with less favorable socioeconomic status (4.7% advanced oral hygiene regimen vs 16.0% controls, OR=4.04 (1.34-15.12), P=.01). CONCLUSION: An advanced oral hygiene program may reduce the risk of spontaneous preterm birth among pregnant patients with moderate-to-severe gingivitis and health disparities. This is the same group that may be at highest risk of poor dental hygiene and preterm birth.

A Randomized Controlled Clinical Trial of Prenatal Oral Hygiene Education in Pregnancy-Associated Gingivitis.

INTRODUCTION: Research shows there is a significant increase in gingival inflammation during pregnancy. This study was conducted to determine if an oral health intervention (OHI), including oral hygiene education delivered by nurse-led staff and an advanced over-the-counter (OTC) oral home care regimen, improved gingival inflammation in pregnant women with moderate-to-severe gingivitis compared with a standard oral hygiene control group. METHODS: This was a multicenter, randomized, controlled, single-masked, parallel group clinical trial conducted in obstetrics clinics of 2 medical centers. A total of 750 pregnant women between 8 and 24 weeks of pregnancy with at least 20 natural teeth and moderate-to-severe gingivitis (>30 intraoral bleeding sites) were enrolled. Participants were randomized to either the OHI group, which included oral hygiene instructions supplemented with an educational video and advanced OTC antibacterial/mechanical oral hygiene products, or the control group receiving oral hygiene instructions and standard products. Both groups received oral hygiene instructions from nurse-led staff. Experienced, masked examiners measured whole mouth gingival index (GI) and periodontal probing depths (PDs) at baseline and months 1, 2, and 3. RESULTS: Participants enrolled in this study presented with moderate-to-severe gingivitis at baseline. Both the OHI and control groups exhibited significant reductions in GI (P < .001) and PD (P < .03) from baseline that persisted throughout the study period. The OHI group exhibited modest, yet statistically greater, reductions in GI (P ≤ .044) compared with the control at all time points. The reduction in PD directionally favored the OHI group, but between-group differences were small (<0.03 mm) and not statistically significant (P > .18). DISCUSSION: Significant gingivitis was prevalent among participants in this study and identifies an opportunity to improve gingival health during pregnancy by providing oral health education during the course of prenatal care when coupled with an advanced OTC oral hygiene regimen.

Parameters for pyrethroid insecticide QSAR and PBPK/PD models for human risk assessment.

In this review we have examined the status of parameters required by pyrethroid QSAR-PBPK/PD models for assessing health risks. In lieu of the chemical,biological, biochemical, and toxicological information developed on the pyrethroids since 1968, the finding of suitable parameters for QSAR and PBPK/PD model development was a monumental task. The most useful information obtained came from rat toxicokinetic studies (i.e., absorption, distribution, and excretion), metabolism studies with 14C-cyclopropane- and alcohol-labeled pyrethroids, the use of known chiral isomers in the metabolism studies and their relation to commercial products. In this review we identify the individual chiralisomers that have been used in published studies and the chiral HPLC columns available for separating them. Chiral HPLC columns are necessary for isomer identification and for developing kinetic values (Vm,, and Kin) for pyrethroid hydroxylation. Early investigators synthesized analytical standards for key pyrethroid metabolites, and these were used to confirm the identity of urinary etabolites, by using TLC. These analytical standards no longer exist, and muste resynthesized if further studies on the kinetics of the metabolism of pyrethroids are to be undertaken.In an attempt to circumvent the availability of analytical standards, several CYP450 studies were carried out using the substrate depletion method. This approach does not provide information on the products formed downstream, and may be of limited use in developing human environmental exposure PBPK/PD models that require extensive urinary metabolite data. Hydrolytic standards (i.e., alcohols and acids) were available to investigators who studied the carboxylesterase-catalyzed hydrolysis of several pyrethroid insecticides. The data generated in these studies are suitable for use in developing human exposure PBPK/PD models.Tissue:blood partition coefficients were developed for the parent pyrethroids and their metabolites, by using a published mechanistic model introduced by Poulin and Thiele (2002a; b) and log DpH 7.4 values. The estimated coefficients, especially those of adipose tissue, were too high and had to be corrected by using a procedure in which the proportion of parent or metabolite residues that are unbound to plasma albumin is considered, as described in the GastroPlus model (Simulations Plus, Inc.,Lancaster, CA). The literature suggested that Km values be adjusted by multiplying Km by the substrate (decimal amount) that is unbound to microsomal or CYPprotein. Mirfazaelian et al. (2006) used flow- and diffusion-limited compartments in their deltamethrin model. The addition of permeability areas (PA) having diffusion limits, such as the fat and slowly perfused compartments, enabled the investigators to bring model predictions in line with in vivo data.There appears to be large differences in the manner and rate of absorption of the pyrethroids from the gastrointestinal tract, implying that GI advanced compartmental transit models (ACAT) need to be included in PBPK models. This is especially true of the absorption of an oral dose of tefluthrin in male rats, in which 3.0-6.9%,41.3-46.3%, and 5.2-15.5% of the dose is eliminated in urine, feces, and bile,respectively (0-48 h after administration). Several percutaneous studies with the pyrethroids strongly support the belief that these insecticides are not readily absorbed, but remain on the surface of the skin until they are washed off. In one articular study (Sidon et al. 1988) the high levels of permethrin absorption through the forehead skin (24-28%) of the monkey was reported over a 7- to 14-days period.Wester et al. (1994) reported an absorption of 1.9% of pyrethrin that had been applied to the forearm of human volunteers over a 7-days period.SAR models capable of predicting the binding of the pyrethroids to plasma and hepatic proteins were developed by Yamazaki and Kanaoka (2004), Saiakhov et al. (2000), Colmenarejo et al. (2001), and Colmenarejo (2003). QikProp(Schrodinger, LLC) was used to obtain Fu values for calculating partition coefficients and for calculating permeation constants (Caco-2, MDCK, and logBBB). ADMET Predictor (Simulations Plus Inc.) provided Vm~,x and Km values for the hydroxylation of drugs/pyrethroids by human liver recombinant cytochrome P450 enzymes making the values available for possible use in PBPK/PD models.The Caco-2 permeability constants and CYP3A4 Vmax and Km values are needed in PBPK/PD models with GI ACAT sub models. Modeling work by Chang et al.(2009) produced rate constants (kcat) for the hydrolysis of pyrethroids by rat serumcarboxylesterases. The skin permeation model of Potts and Guy (1992) was used topredict K, values for the dermal absorption of the 15 pyrethroids.The electrophysiological studies by Narahashi (1971) and others (Breckenridgeet al. 2009; Shafer et al. 2005; Soderlund et al. 2002; Wolansky and Harrill 2008)demonstrated that the mode of action of pyrethroids on nerves is to interfere with the changes in sodium and potassium ion currents. The pyrethroids, being highly lipid soluble, are bound or distributed in lipid bilayers of the nerve cell membrane and exert their action on sodium channel proteins. The rising phase of the action potential is caused by sodium influx (sodium activation), while the falling phase is caused by sodium activation being turned off, and an increase in potassium efflux(potassium activation). The action of allethrin and other pyrethroids is caused by an inhibition or block of the normal currents. An equation by Tatebayashi and Narahashi (1994) that describes the action of pyrethroids on sodium channels was found in the literature. This equation, or some variation of it, may be suitable for use in the PD portion of pyrethroid PBPK models.

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.

Multilocus Sequence Typing of Mycoplasma ovipneumoniae Detected in Dall's Sheep (Ovis dalli dalli) and Caribou (Rangifer tarandus grantii) in Alaska, USA.

In 2018, Mycoplasma ovipneumoniae was detected in free-ranging caribou (Rangifer tarandus grantii) and Dall's sheep (Ovis dalli dalli) in Alaska, US. Evaluation of additional nasal swabs and archived tissues for M. ovipneumoniae suggested that this bacterium was widespread geographically and temporally in populations of both species. Multilocus sequence typing of four loci identified a single, novel, apparently stable strain type of M. ovipneumoniae in 11 Dall's sheep and 15 caribou in multiple populations across Alaska sampled over a period of 15 yr (2004-19). This strain type differs from those detected to date from wild or domestic sheep (Ovis aries) or goats (Capra aegagrus hircus) tested in Alaska or the lower 48 states. Although the population health implications of this strain are unknown, it has not been associated with population-wide mortality events. The presence of this strain does not decrease the potential risk from the introduction of a pathogenic M. ovipneumoniae strain associated with severe disease in other wildlife populations; therefore, continued monitoring for signs of disease and additional strains is important.