Comparative efficacy of two treatment regimens combining in-office and at-home programs for dentin hypersensitivity relief: a 24-week clinical study.

PURPOSE: Dentin hypersensitivity is a significant clinical problem that affects numerous individuals. This sharp pain, arising from exposed dentin in response to external stimuli, can be a particularly uncomfortable and unpleasant sensation for patients, because it interferes with their quality of life. The objective of this 24-week, single-center, parallel group, double-blind, stratified and randomized clinical study was to evaluate the clinical efficacy of a single professional treatment with an in-office desensitizing paste followed by twice daily brushing with a desensitizing toothpaste and toothbrush for 24 weeks. METHODS: 100 adults with confirmed dentin hypersensitivity were randomly assigned into two groups. One group received a single in-office treatment with a desensitizing paste containing 8% arginine and calcium carbonate (marketed as Colgate Sensitive Pro-Relief Desensitizing Paste and Elmex Sensitive Professional desensitizing paste), after dental scaling, followed by 24 weeks of brushing twice daily with a desensitizing toothpaste containing 8% arginine, calcium carbonate with 1450 ppm fluoride as MFP (marketed as Colgate Sensitive Pro-Relief toothpaste and Elmex Sensitive Professional toothpaste) and using the Colgate Sensitive Pro-Relief toothbrush (Test Group). The other group received a single in-office treatment with Nupro-M pumice prophylaxis paste, after dental scaling, followed by 24 weeks of brushing twice daily with a non-desensitizing toothpaste containing 1450 ppm fluoride as MFP and with the Oral-B Indicator toothbrush (Negative Control Group). Hypersensitivity was reexamined immediately after in-office product application and after 8 and 24 weeks of twice daily brushing. RESULTS: Immediately after professional product application, and after 8 and 24 weeks, subjects assigned to the Test Group demonstrated statistically significant improvements in dentin hypersensitivity compared to subjects assigned to the Negative Control Group in tactile (49.8%, 57.5% and 32.9%, respectively) and air blast (26.0%, 38.4% and 34.3%, respectively) sensitivity scores. The instant reductions in dentin hypersensitivity provided by the single professional application of a desensitizing paste for in-office use, containing 8% arginine and calcium carbonate were maintained by twice daily brushing with the 8% arginine, calcium carbonate toothpaste with 1450 ppm fluoride as MFP and the Colgate Sensitive Pro-Relief toothbrush for at least 24 weeks.

Clinical evaluation of the efficacy of a desensitizing paste containing 8% arginine and calcium carbonate for the in-office relief of dentin hypersensitivity associated with dental prophylaxis.

PURPOSE: To evaluate the clinical efficacy in reducing dentin hypersensitivity of a professional desensitizing paste containing 8% arginine and calcium carbonate relative to that of a commercially-available pumice prophylaxis paste when applied pre-procedurally to a professional dental cleaning (dental prophylaxis). METHODS: This was a single-center, parallel group, double-blind, stratified clinical study, conducted in Langhorne, Pennsylvania. Adult male and female subjects who presented a tactile hypersensitivity score (Yeaple Probe) between 10 and 50 grams of force and an air blast hypersensitivity score of 2 or 3 (Schiff Cold Air Sensitivity Scale) were stratified according to their baseline hypersensitivity scores and randomly assigned within strata to one of two treatment groups. The two treatment groups were: (1) a Test paste, a desensitizing paste containing 8% arginine and calcium carbonate (Colgate-Palmolive Co.); and (2) a Control paste, Nupro pumice prophylaxis paste (Dentsply Professional). Subjects had their assigned paste applied immediately before receiving a professional dental cleaning procedure. After the completion of the dental cleaning procedure, tactile and air blast dentin hypersensitivity examinations were again performed following the same methodology employed for the baseline hypersensitivity examinations. RESULTS: 45 subjects completed the study. At the final hypersensitivity examinations, conducted immediately after the completion of the dental cleaning procedure, subjects assigned to the test group exhibited statistically significant improvements from baseline with respect to baseline-adjusted mean tactile (132.1%) and air blast hypersensitivity scores (48.6%). Additionally, subjects assigned to the control group exhibited a statistically significant hypersensitivity improvement from baseline with respect to baseline-adjusted mean air blast hypersensitivity scores (13.9%). The hypersensitivity improvement from baseline indicated for the control group for mean tactile hypersensitivity scores (21.7%) was not statistically significant. At the final hypersensitivity examinations, statistically significant differences were indicated between the test group and the control group with respect to baseline-adjusted mean tactile (110.0%) and air blast hypersensitivity scores (41.9%).

In vivo quantification of gingival inflammation using spectral imaging.

Erythema is a reaction of the skin and oral soft tissues commonly associated with inflammation and an increase in blood flow. Diffuse reflection spectroscopy is a powerful tool for the assessment of skin inflammation where erythema has been linked to the relative concentration of oxygenated hemoglobin and blood perfusion. Here we demonstrate the applicability of a spectral imaging method for the quantification of gingival inflammation by looking at the gingival margin and papillary tip erythema. We present a longitudinal study on 22 healthy volunteers divided in two groups. The first was allowed to have normal oral hygiene and the second was subjected to an induced gingivitis for two weeks by cessation of oral hygiene. The spectral reflectance ratio at 615 and 460 nm, R(615)R(460), was proposed as a method to quantify and map the erythema spatial distribution. These wavelengths represent spectral absorption crossovers observed between oxygenated and deoxygenated hemoglobin. The spectral method presented shows a significant separation (p<0.01) between the groups when gingivitis was induced and correlates significantly (p<0.05) with the clinical gingival index scores. We believe that these investigations could contribute to the development of functional imaging methods for periodontal disease detection and monitoring.

Over-the-counter decorative contact lenses: Cosmetic or Medical Devices? A Case Series.

PURPOSE: To illustrate the implications of the unauthorized sale and unmonitored wearing of decorative cosmetic contact lenses resulting in ocular complications and to determine the prevalence of the use of cosmetic contact lenses obtained from unlicensed providers by adolescents. METHODS: Observational case report, structured interview, and survey in a retrospective, observational, clinical practice setting. Reported sources of contact lenses were categorized as provider and nonprovider, and associations within the data were reviewed by using a Pearson correlation and chi-square test. RESULTS: Twelve patients (eight female and four male) were seen urgently for acute eye pain and redness after wearing plano decorative contact lenses. None of the patients had previously worn a contact lens. None of the lenses were dispensed by eye care professionals. Four patients developed blinding infections requiring hospital admission. Causative organisms included staphylococci, Pseudomonas, and acanthamoeba. One patient required a penetrating keratoplasty. One hundred fifty-nine patients were surveyed. Thirty-seven (23%) used decorative contact lenses. Lenses were obtained from an unlicensed provider 51% of the time. Education about lens care and handling was significantly associated with acquiring lenses from licensed providers (R = 0.74, P < 0.0001). CONCLUSIONS: Colored noncorrective contact lenses are being dispensed without a prescription or fitting from unlicensed vendors. Patients who acquire lenses from unauthorized providers are significantly less likely to be instructed on appropriate lens use and care. Consequently, uninformed lens wearers are experiencing acute vision-threatening infections and inflammation.

Relationship between prolongation of QTc and prolongation of the peak of T (Tp) to the end of T (Te).

INTRODUCTION: Lengthening of ventricular repolarization is known to be a risk factor for development of torsade de pointes, a form of ventricular tachycardia thought to be initiated by an early after depolarization and to be sustained by a novel reentrant mechanism precipitated, putatively, by heterogeneity of repolarization among ventricular myocytes. While prolongation of QT and QTc are good predictors of torsdogenic potential, the duration from the peak to the end of the T wave (Tp-Te) is thought to be a more accurate reflection of heterogeneity of ventricular repolarization. This study, conducted on Langendorff guinea pig hearts, was designed to compare lengthening of QTc with lengthening of Tp-Te for 16 test articles known to be and 7 known not to be torsadogenic. METHODS: Bipolar, transventricular electrograms, recorded from 83 guinea pig hearts perfused according to methods of Langendorff, were exposed to escalating concentrations of test articles. RR, QT, QTc and Tp-Te were measured. QTc was calculated by the method of Fridericia. Data was analyzed using a mixed model ANOVA where least squared means (t-test) was used for comparing males vs. females and for concentration levels for each parameter studied. RESULTS: QTc lengthened in 16 of 16 test articles known to be torsadogenic and did not lengthen in 7 of 7 test articles known not to be torsadogenic--sensitivity and specificity of 1.0. In 9 out of 16 torsadogenic test compounds, the Tp-Te interval increased parallel with QTc. In 7 test compounds known not to be torsadogenic, two test compounds increased Tp-Te. DISCUSSION: It is clear that QTc prolongation is a more robust predictor of torsadogenicity than Tp-Te in the male guinea pig heart.

Effects of ambasilide in isolated perfused guinea pig heart: use dependence.

There has been increased interest in class III antiarrhythmic drugs for con-version of atrial fibrillation to sinus rhythm. Ambasilide, a class III antiarrhythmic, has been shown to block multiple cardiac channels in a variety of animals including humans. Although the electrophysiological effects of ambasilide are characterized on the cellular level, its effects on an organ level have yet to be investigated. We investigated escalating doses of ambasilide in isolated, per-fused guinea pig hearts. Ambasilide prolonged the RR, PQ, QRS, QT, and QTc (F) in a concentration-dependent manner in either normal sinus rhythm or with reduced heart rate (atriectomy). dP/dtmin was increased (became less negative) in the presence of increasing concentrations of ambasilide, whereas the vehicle produced less negative lusitropy. Ambasilide demonstrated use dependence by prolonging QTc (F) less at slower heart rates. Ambasilide also inhibited isoproterenol-induced tachycardia, suggesting it exerts beta-adrenergic blocking properties. In conclusion, this study suggests that ambasilide has multichannel blocking properties including beta-adrenergic antagonism.

Effects of thalidomide on QTc, inotropy, and lusitropy in the isolated guinea pig heart.

There has been a resurgence in the use of thalidomide over the past several years; however, little is known about its potential cardiac toxicity. Isolated, perfused guinea pig hearts were exposed to escalating concentrations of thalidomide or vehicle, and changes in RR interval, QT duration and QTc duration, and left ventricular inotropy and lusitropy comparing escalating concentrations of thalidomide with vehicle were sought. RR interval lengthened and QTc prolonged significantly at 10 microM concentrations. QT did not change. dP/dtmax increased and dP/dtmin decreased in response to thalidomide. Based on results using this preparation, thalidomide has a potential liability for lengthening QTc, but only at concentrations of 10 microM or greater. It possesses both positive inotropic and positive lusitropic properties.

QT and RR intervals in conscious and anesthetized guinea pigs with highly varying RR intervals and given QTc-lengthening test articles.

A facile system for obtaining electrocardiograms from conscious animals was used to conduct studies on 12 animals studied both conscious and anesthetized, on 4 conscious animals given vehicle (0.5% methylcellulose) and QT-lengthening test articles, and on 6 animals given test articles thought to not lengthen QTc. In 12 animals whose ECGs were monitored via a bipolar transthoracic ECG, heart rates were slowed with 1.0 mg/kg zatebradine, while they were conscious in their slings, and after being anesthetized with ketamine/xylazine. The following regression equations were obtained relating QT to RR: QT = 44.7 ln RR - 132.9, r2 = 0.7, for conscious animals; QT = 79.4 ln RR - 287.4, r2 = 0.8 for anesthetized animals, with RR intervals varying between 150 and 550 ms. The anesthetic increases QT at all RR intervals (p < 0.001), but does not change the slope of the relationship between QT and RR when compared with the conscious guinea pig. The Fridericia method was best for correcting QT for RR interval in conscious guinea pigs, but the Bazett method was best for correcting in anesthetized animals. QTc lengthened significantly in all conscious guinea pigs given, orally, cisapride, ketoconazole, and sotalol (positive test articles) and did not change with methylcellulose (the vehicle) or with propranolol, verapamil, or enalapril (negative controls). These techniques and relationships demonstrate that this methodology may be useful in exploring torsadogenic effects of novel pharmacological entities.