A comparative 3-month clinical investigation of the safety and efficacy of a battery-operated and a rechargeable oscillating-rotating power toothbrush.

PURPOSE: To compare the safety and efficacy of two oscillating-rotating power toothbrushes, the rechargeable Braun Oral-B D8 and the battery-powered Colgate Actibrush. MATERIALS AND METHODS: This was a randomized, examiner-blind, parallel-group study, carried out over 3 months of product use, involving a total of 113 healthy subjects with a plaque score of > or = 1.5 and a gingivitis score of > or = 1.1. Subjects were given written and verbal instructions in the use of their respective power brushes and were told to brush twice per day. At baseline, hard and soft tissues were examined, and plaque scores and gingival scores were recorded after 12-18 hrs of no oral hygiene. Subjects returned after 3 months, at which time soft and hard tissues were re-examined and plaque and gingivitis scores were recorded. RESULTS: No evidence was found of soft or hard tissue trauma and both brushes were considered to be safe when used according to the manufacturers' instructions. After 3 months, whole mouth plaque scores had decreased by 7% in the D8 group but had increased by 4.3% in the Actibrush group. The decrease from baseline in the D8 group was statistically significant, but the increase in the Actibrush group was not. The difference between the two groups was statistically significant both for the whole mouth and all individual sites. Whole mouth gingivitis scores were also reduced significantly from baseline in both groups, by 22.5% in the D8 group and by 17.5% in the Actibrush group. For whole mouth scores and all individual sites (interproximal, buccal and lingual), the D8 was significantly more effective than the Actibrush.

Anticalculus efficacy of an antiseptic mouthrinse containing zinc chloride.

BACKGROUND: The authors undertook a controlled clinical study to determine the efficacy of a tartar-control antiseptic mouthrinse in inhibiting the development of supragingival dental calculus. METHODS: After undergoing a dental prophylaxis, 334 subjects with a moderate rate of calculus formation were stratified and randomly assigned to one of three groups: positive control (using a tartar-control toothpaste and an antiseptic rinse), negative control (using a regular toothpaste and an antiseptic mouthrinse) or experimental (using a regular dentifrice and a tartar-control mouthrinse). Subjects brushed and rinsed twice daily, unsupervised, for four months. The researchers assessed subjects' calculus levels using the Volpe-Manhold Index, or VMI, after 16 weeks. RESULTS: Using analysis of covariance, the authors found that both the experimental group (which used a tartar-control rinse containing zinc chloride) and the positive control group (which used a tartar-control dentifrice containing pyrophosphate) demonstrated statistically significantly lower VMI scores (P = .001) than the negative control group (which used a regular dentifrice and an antiseptic rinse). Both anticalculus agents provided a clinically relevant 21 percent reduction in calculus formation. CONCLUSION: An antiseptic mouthrinse containing 0.09 percent zinc chloride as the anticalculus agent provides a clinically relevant reduction in calculus formation in people with a moderate rate of such formation. CLINICAL IMPLICATIONS: A tartar-control mouthrinse with zinc chloride as the tartar-control ingredient is clinically effective in reducing the formation of calculus.

Efficacy of baking soda-containing chewing gum in removing natural tooth stain.

A 14-week, double-blind, randomized clinical trial was conducted with 126 healthy volunteers to compare the efficacy of twice-daily use of 3 baking soda-containing chewing gums in removing natural tooth stain when used in conjunction with a program of regular oral hygiene. All 3 chewing gums significantly reduced extrinsic stain (P < .0001) and improved the whitened appearance of teeth (P < .0001) at both the 2-week interim and the final 4-week evaluations. ARM & HAMMER DENTAL CARE The Baking Soda Gum (AHDC) reduced dental stain by 70.8%, compared to reductions of 71.9% and 65.3%, after use of 2 experimental gum formulations. Whitened appearance improved by 1.73 shade tabs using AHDC gum, and up to 2.49 shade tabs with the experimental formulations. These results suggest that the use of baking soda-containing gum after meals, in conjunction with good oral hygiene, can improve both extrinsic dental staining and the whitened appearance of teeth.

A single-use and 3-month clinical investigation of the comparative efficacy of a battery-operated power toothbrush and a manual toothbrush.

PURPOSE: To compare the safety and efficacy of a manual toothbrush and a battery-operated power toothbrush in two separate studies, one utilizing a single-use design and the other a 3-month parallel-group design. MATERIALS AND METHODS: The toothbrushes compared in the two studies were the Oral-B CrossAction manual toothbrush and the Colgate Actibrush battery-operated power toothbrush. The single-use study, which used a single-blind, cross-over design, involved 71 healthy subjects, who were instructed to abstain from oral hygiene for 23-25 hours prior to brushing with each of the two toothbrushes. Plaque was measured using the Proximal Marginal Index (PMI) pre- and post-brushing. The 3-month parallel-group study involved a total of 113 subjects who had plaque (PMI), gingivitis and bleeding (Loe and Silness) scored at baseline and after 1 and 3 months of product use. RESULTS: In both studies, the two toothbrushes were found to be safe. In the single-use study, significantly greater amounts of plaque were removed by the CrossAction manual toothbrush than by the Actibrush for the whole mouth as well as for marginal and approximal sites (P < 0.001). In the 3-month study, significantly greater plaque reduction was achieved with the CrossAction brush, the advantage being significant at 1 month for all sites except lingual sites (P < 0.05). At 3 months, there were consistent numerical advantages in favor of the CrossAction at all sites except lingual sites. Reductions in gingivitis were found to be similar with both toothbrushes.

Comparative investigation of the desensitizing efficacy of a new dentifrice: a 14-day clinical study.

The effect on dentinal hypersensitivity from the use of a new formulation dentifrice containing 5.0% potassium nitrate and 0.454% stannous fluoride in a silica base (Colgate Sensitive Maximum Strength Toothpaste, Colgate-Palmolive Co.) over a 14-day period was compared to a commercially available, nondesensitizing control dentifrice (Colgate Winterfresh Gel, Colgate-Palmolive Co.). A total of 66 subjects were entered into and completed the study. They were stratified into two balanced groups according to their baseline mean tactile (Yeaple Probe) sensitivity scores and air blast (thermal) sensitivity scores. The two groups were randomly assigned to use either the new formulation dentifrice or the commercially available control dentifrice. Participants were instructed to brush their teeth twice daily (morning and evening) for 1 minute with their assigned dentifrice and a commercially available soft-bristled toothbrush. Dentinal hypersensitivity examinations (tactile and air blast sensitivity) were conducted at baseline and after 3, 7, 10, and 14 days' use of the products. All examinations were conducted by the same examiner. Participants who used the new formulation dentifrice containing potassium nitrate/stannous fluoride/silica demonstrated a statistically significant improvement in both tactile sensitivity and air blast sensitivity after 10 and 14 days' use of the dentifrice (p < 0.05), as compared to a commercially available control dentifrice. It was concluded that a new dentifrice formulation containing 5.0% potassium nitrate and 0.454% stannous fluoride in a silica base provided a statistically significant reduction in dentinal hypersensitivity after only 10 days, as compared to a commercially available nondesensitizing control dentifrice.

Clinical study to compare extrinsic stain formation in subjects using three dentifrice formulations.

The purpose of this study was to compare the degree of extrinsic dental stain formed with the use of three dentifrices: (1) a new dentifrice formulation containing 5.0% potassium nitrate and 0.454% stannous fluoride in a silica base (Colgate Sensitive Maximum Strength Toothpaste, Colgate-Palmolive Co.); (2) a commercially available dentifrice containing 5.0% potassium nitrate and 0.243% sodium fluoride in a silica base (Sensodyne Fresh Mint Toothpaste, Block Drug Company, Inc.); and (3) a dentifrice containing 0.243% sodium fluoride in a silica base (Colgate Winterfresh Gel, Colgate-Palmolive Co.). A total of 121 participants were entered into the study and stratified into 3 balanced groups according to baseline mean Lobene Stain Index scores. A thorough dental prophylaxis was completed on each participant after completion of the baseline examination. The three groups were randomly assigned to use one of the three dentifrices. The groups were well balanced with regard to mean baseline stain index scores, gender, and tobacco habits. Participants were instructed to brush their teeth twice daily (morning and evening) for 1 minute with their assigned dentifrice and a commercially available soft-bristled toothbrush. Extrinsic dental stain examinations, which measured dental stain area and dental stain intensity, were conducted at baseline and 4 and 8 weeks. Examinations were conducted by the same dental examiner at each examination. After 4 and 8 weeks' use of the test dentifrices, there was no statistically significant difference regarding extrinsic stain formation with the use of any of the dentifrices. Thus, it can be concluded from this study that the use of a new formulation dentifrice containing 5.0% potassium nitrate and 0.454% stannous fluoride in a silica base will not result in a greater formation of extrinsic dental staining than that which is formed by two commercially available dentifrices not known to cause extrinsic dental stain.

Anticalculus effect of two zinc citrate/essential oil-containing dentifrices.

PURPOSE: To assess the feasibility of incorporating zinc citrate, a known anticalculus ingredient, into a dentifrice formulation containing a fixed combination of essential oils, a known antiplaque/antigingivitis agent. MATERIALS AND METHODS: This randomized, parallel, double-blind study evaluated the potential of two essential oil dentifrice formulations containing different levels of zinc citrate (1.0% and 2.0% ZCT) to reduce supragingival calculus formation compared to a marketed control dentifrice, Crest Regular. Following a 3-month pre-test phase, subjects received a dental prophylaxis, were stratified into three balanced groups on the basis of Volpe-Manhold calculus scores and brushed twice daily with their assigned dentifrice for 3 months. RESULTS: One hundred ninety-six evaluable subjects completed all phases of the study. ANCOVA revealed that the 1.0% ZCT and 2.0% ZCT essential oil dentifrice formulations provided significant reductions in calculus formation of 26.4% and 29.0% (P< 0.001), respectively, compared to the control dentifrice, Crest Regular. The magnitude of calculus reductions is similar to those levels obtained by other zinc salt formulations.

A clinical comparison of two calculus-inhibiting dentifrices.

The objective of this double-blind clinical study, conducted in harmony with the Volpe-Manhold design for studies of dental calculus, was to compare the effect on supragingival calculus formation of a dentifrice containing pyrophosphate, tripolyphosphate and a copolymer in a 0.243% sodium fluoride/silica base (Test Dentifrice), to that of a commercially available calculus-inhibiting dentifrice containing tetrapotassium pyrophosphate, disodium pyrophosphate and tetrasodium pyrophosphate in a 0.243% sodium fluoride/silica base (Positive Control Dentifrice). Adult male and female subjects from the Buffalo, New York area were entered into the study, provided a full oral prophylaxis, and assigned the use of a placebo (non-calculus-inhibiting) dentifrice for fourteen weeks. At the completion of this initial period, subjects were assessed for baseline Volpe-Manhold Calculus Index scores, provided another full prophylaxis, and stratified into two treatment groups which were balanced for age, sex and baseline calculus. Subjects were instructed to brush their teeth twice daily (morning and evening) for one minute with their assigned dentifrice, using a soft-bristled toothbrush. Examinations for dental calculus were again performed after twelve weeks' use of the study dentifrices. Ninety-one (91) subjects complied with the protocol and completed the entire study. At the three-month examination, the Test Dentifrice group exhibited a statistically significant 27.3% reduction in mean Volpe-Manhold Calculus Index score as compared to the Positive Control Dentifrice group. The results of this clinical study support the conclusion that a new calculus-inhibiting dentifrice, containing pyrophosphate, tripolyphosphate and a copolymer in a 0.243% sodium fluoride/silica base, is efficacious for the control of the development of supragingival calculus, and provides a level of benefit greater than that provided by a commercially available calculus-inhibiting dentifrice containing tetrapotassium pyrophosphate, disodium pyrophosphate and tetrasodium pyrophosphate in a 0.243% sodium fluoride/silica base.

Immunogenic and protective response in mice immunized with a purified, inactivated, Dengue-2 virus vaccine prototype made in fetal rhesus lung cells.

The feasibility of a purified, inactivated vaccine (PIV) against dengue type 2 (DEN-2) virus was explored. Dengue-2 virus strain 16681 was used for producing a monotypic PIV. Virus adapted to fetal rhesus lung (FRhL-2) cells was harvested from roller bottle culture supernatant fluids, concentrated, and purified on sucrose gradients. Analysis of purified virus preparations by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting showed primarily envelope (E) and premembrane (prM) antigens. These preparations had a purity, estimated from silver-stained gels, of approximately 70%, and a yield, based on recovery of virus and viral antigen, of 10-20%. The purified virus was inactivated with 0.05% formalin at 22 degrees C, or alternatively, with 7 mRads from a 60Co source. Vaccinated mice developed high titers of anti-DEN-2 virus neutralizing antibody and were partially protected from virus challenge. These results warrant further testing and development of PIVs for the other DEN virus serotypes.

The role of limbic structures in the modulation of ACTH responses following adrenalectomy.

The role of the HIPP, DF, and the lateral SPT as well as of the central AMG nucleus in ACTH hypersecretion following Adex, was studied in male rats. In animals with bilateral dorsal hippocampectomy, DF section, or SPT lesions there was a much greater increase in ACTH hypersecretion when compared to Adex alone. Implants of CS in the paraventricular nucleus of the hypothalamus prevented the rise in serum ACTH following Adex, and this effect was reversed by hippocampectomy. Bilateral lesions in the AMG prevented the Adex-induced rise of serum ACTH. These results indicate that the dorsal HIPP and its efferent pathways to the hypothalamus have normally an inhibitory effect on Adex-induced ACTH secretion. Their removal permits an elevated ACTH hypersecretion as well as attenuation of the CS feedback effect. The central AMG nucleus, which has a facilitatory effect on the hypothalamopituitary-adrenocortical axis, can also modulate ACTH secretion following Adex.

Effects of HSV-1, a neurotropic virus, on the hypothalamic-pituitary-adrenocortical axis in rats.

It is well established that the hypothalamic-pituitary-adrenocortical (HPA) axis is activated during systemic viral diseases. In this study we examined the effects of a neurotropic virus, herpes simplex virus type 1 (HSV-1), on the HPA axis in male rats. Following corneal inoculation with HSV-1, the virus invaded the nervous system and replicated in the brainstem without clinical signs of disease. During this asymptomatic brainstem infection with HSV-1, significant changes were found in the function of the HPA axis: On days 3, 7 and 14 post-infection (p.i.) basal ACTH and corticosterone (CS) levels were markedly elevated, and photic stressful stimulation failed to further increase the levels of these hormones. In addition, the elevated basal serum levels of ACTH and CS could not be suppressed by pretreatment with dexamethasone. The content of CRF-41 in the paraventricular nucleus of the hypothalamus and in the median eminence measured at 6 days p.i. was similar to that of vehicle inoculated rats. By 4 weeks p.i. the basal levels of ACTH and CS returned to normal and these animals responded to photic stimulation and dexamethasone similar to vehicle inoculated rats. Systemic (intraperitoneal) inoculation of HSV-1 did not induce any changes in the HPA axis responses. We therefore suggest that asymptomatic acute infection of the brainstem with HSV-1 may affect brain regions involved in the regulation of the HPA axis, and that those effects are mediated centrally and not by a systemic mechanism.

Limbic pathways and hypothalamic neurotransmitters mediating adrenocortical responses to neural stimuli.

One of the major phenomena related to the stress response is the activation of the hypothalamo-pituitary-adrenocortical (HPA) axis. This axis consists of corticotropin releasing factor-41 in the paraventricular nucleus of the hypothalamus (PVN), which in response to a variety of stimuli is released into the portal circulation and stimulates pituitary ACTH secretion and subsequently adrenocortical discharge. The mechanisms involved in the activation are not uniform and the responses to various stimuli are mediated by different neural pathways. Since extrahypothalamic limbic structures play a significant role in the HPA function, it is the purpose of this review to describe the neural pathways between the hippocampus, septum and amygdala and the hypothalamus in relation to adrenocortical activity and the differential role of the medial forebrain bundle as well as the effects of various hypothalamic deafferentation on the transmission of the neural impulses to the hypothalamus. Also, the importance of norepinephrine and serotonin in the activation of the HPA axis will be delineated.

Differential effect of amygdaloid lesions on CRF-41, ACTH and corticosterone responses following neural stimuli.

The effect of amygdaloid (AMG) lesions on changes in median eminence (ME) CRF-41 and serum ACTH and corticosterone (CS) levels following neural stimuli were investigated in rats. In intact animals photic or acoustic stimuli caused CRF-41 depletion from the ME and a rise in serum ACTH and CS levels. In rats with medial or central AMG nuclei lesions, these responses were blocked. Basal AMG lesions were not effective. Also, all groups of animals responded normally to ether stress. These results indicate a differential effect of AMG nuclei on the hypothalamo-pituitary-adrenocortical (HPA) axis and demonstrate that the facilitatory effect of the AMG nuclei on the HPA axis responses involves the release of ME CRF-41, which stimulates ACTH and consequently CS secretion.

Clinical effect of a triclosan-containing dentifrice on plaque and gingivitis: a six-month study.

A total of 294 adult male and female subjects completed a 6-month, double-blind clinical trial designed to evaluate the effects of a dentifrice which contained 0.3% triclosan in conjunction with 2% of a methoxyethylene/maleic acid copolymer in a 0.243% sodium fluoride/silica base, relative to a control dentifrice, on supragingival plaque accumulation and gingivitis. Plaque and gingivitis were scored after 3 and 6-month use of the assigned dentifrice. At the end of the study, the triclosan group showed an average reduction, relative to the control group, of 12% in plaque accumulation and 20% in gingivitis. Both were statistically significant at p < or = 0.0001. The effect of the triclosan dentifrice was most pronounced on the more severe manifestations of plaque and gingivitis. The improvement in the gingival parameters at 6-months relative to the control dentifrice was statistically significant at p < or = 0.0001. It was concluded that the twice-daily use of the triclosan-containing dentifrice resulted in significant reduction in supragingival plaque formation and a significant improvement in gingival health without the presence of any extrinsic staining or objectionable taste.

Differential recovery of adrenocortical responses to neural stimuli following administration of 5,7-dihydroxytryptamine into the hypothalamus.

In view of the role of serotonin in adrenocortical regulation, the effects of depletion of hypothalamic serotonin, using localized injections of the neurotoxin 5,7-dihydroxytryptamine into the hypothalamic paraventricular nucleus, on the rise in plasma corticosterone following afferent neural stimulation, were studied. The neurotoxin caused a significant reduction (p less than 0.001) in hypothalamic serotonin content of about 50% during the first month and about 30% up to two months later. Basal and ether stress-induced rises in plasma corticosterone levels were unaffected at all times after this treatment, but responses to stimulation of the sciatic nerve were reduced for up to four weeks (p less than 0.01), recovering at later times. Responses to photic and acoustic stimuli were almost entirely prevented up to four weeks following the treatment (p less than 0.001) but showed a gradual recovery to full, or almost full, adrenocortical responses at eight weeks, following acoustic and photic stimulation respectively. These results demonstrate a differential recovery of the adrenocortical responses, following the neurotoxin injection and indicate that different neural modalities require different 5-HT concentrations in the PVN for the expression of a full adrenocortical response.

Adrenal responses and neurotransmitters in posterior hypothalamic deafferentation.

The effects of a small posterior hypothalamic deafferentation (PHD) on adrenocortical responses to peripheral neural stimuli were investigated in rats. PHD inhibited the rise in plasma corticosterone (CS) following photic and acoustic stimulation, but did not affect the adrenocortical response following sciatic nerve stimulation. PHD did not change the content of norepinephrine in the paraventricular nucleus of the hypothalamus, however, it reduced the serotonin content by about 30%. The possible role of serotonin or of another tonic caudal input into the hypothalamus for the activation of the pituitary-adrenocortical axis, following certain neural stimuli, is discussed.

The preoptic area and bed nucleus of the stria terminalis are involved in the effects of the amygdala on adrenocortical secretion.

In view of the role of the amygdala in the modulation of adrenocortical secretion we have studied the neural pathways which mediate this response. Changes in plasma corticosterone following medial amygdala stimulation, under pentobarbital anaesthesia, were studied in rats which chronically implanted electrodes in intact and lesioned animals. The rise in plasma corticosterone following amygdala stimulation was inhibited by bilateral lesions of the stria terminals, medial preoptic area, and bed nucleus of the stria terminalis, and to a greater extent by a combined lesion of the latter two structures. The combined lesion also completely blocked the adrenocortical response to olfactory stimulation. These various lesions did not affect, however, the rise in plasma corticosterone following ether stress. These data thus demonstrate that the stria terminalis, preoptic area and bed nucleus of the stria terminalis are involved in the transmission of neural impulses to the hypothalamus which activate adrenocortical secretion.

Effect of interleukin-1 on adrenocortical activity in intact and hypothalamic deafferentated male rats.

The present study was designed to elucidate the site of action of interleukin 1 (IL-1) modulation of the hypothalamic-hypophyseal-adrenal (HHA) axis. An intraperitoneal injection of recombinant human IL-1 beta (160 U/rat) significantly elevated serum levels of ACTH and corticosterone (CS). In rats with complete mediobasal hypothalamic deafferentation, the HHA response to IL-1 was inhibited. An intracerebroventricular injection of rIL-1 (2 U/rat) caused a marked increase in serum ACTH and CS. These results suggest that IL-1 activates the HHA axis by a direct effect upon the brain, and that intact neural connections between the mediobasal hypothalamus and extrahypothalamic brain regions are essential for IL-1-induced HHA responses.

Hypothalamic norepinephrine mediates limbic effects on adrenocortical secretion.

The purpose of this study was to elucidate the role of norepinephrine (NE) in the mediation of adrenocortical responses following limbic stimuli. The effects of stimulation of the dorsal and ventral hippocampus and the midbrain reticular formation on the plasma corticosterone (CS) levels was studied in rats with vehicle or 6-hydroxydopamine (6-OHDA) injected bilaterally into the paraventricular nucleus of the hypothalamus (PVN). The injection of 6-OHDA caused a very significant reduction in the concentration of PVN NE and blocked the rise in plasma CS following the stimulation of the above three limbic structures. The basal CS level and the response to ether stress were not affected. The present study supports previous observations on the stimulatory role of NE on CS secretion and that the modulatory effects of extrahypothalamic limbic structures on the adrenocortical activity depend on the presence of NE in the PVN.