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Biomedical subjects

M Addy

Publications and source records attributed to M Addy.

At least 37 records · Page 2Linked to original sources

Control of supragingival calculus. Scaling and polishing and anticalculus toothpastes: an opinion.

The removal of supragingival calculus by scaling and polishing of the teeth is only one aspect of a dental prophylaxis. However in many countries, a large number of individuals only require and receive, at regular intervals, a supragingival scale and polish. The association of supragingival calculus to gingival and periodontal disease is unclear, however, it is logical to assume a plaque retention role. Moreover, for the individual, supragingival calculus may pose cosmetic problems. Regular calculus removal is both time consuming and exacting for dental professionals and has important financial implications to patients and/or health schemes. The benefits of regular supragingival calculus removal are not established, yet potential detrimental effects for the patient are known, and certain groups are susceptible to systemic disease consequent on scaling and polishing of the teeth. The oral hygiene habits of most individuals appear insufficient to prevent the reformation of supragingival calculus once removed and for this reason chemical inhibition is an attractive proposition. Most success to date has been with agents which inhibit crystal growth, notably pyrophosphates, and toothpaste products are available containing such agents. Clinical studies support efficacy for some products and indicate that the magnitude of calculus inhibition would reduce the need for or frequency of scaling and polishing of teeth in a proportion of individuals. Anticalculus toothpastes would appear to be proven worthy of recommendation for those individuals in whom supragingival calculus formation is a problem.

Bacteremia

The magnitude and duration of the effects of some mouthrinse products on salivary bacterial counts.

The persistence of action or substantivity of an antimicrobial agent in the mouth relates to the plaque inhibitory action of that compound. Substantivity can be assessed by measuring the magnitude and duration of the fall in salivary bacteria following single rinses with antimicrobials. This was a randomised single-blind, cross-over study measuring the effects of single 60-s rinses of 5 mouthwash products on salivary bacterial counts in 14 healthy human volunteers. Effects over a 7-h period were compared with a chlorhexidine rinse product (positive control) and saline (negative control). All but one rinse, containing cetylpyridinium chloride (CPC), significantly reduced bacterial counts compared to saline up to 5-7 h. No rinse produced the magnitude or duration of effect noted for chlorhexidine and decrements from baseline, with one exception, were highly significantly lower than with the chlorhexidine product. Comparing the 2 CPC rinses, the findings suggest that the activity of one product was vitiated by some other ingredient. The triclosan/copolymer, the essential oil/phenolic and one CPC products exhibited similar persistence. In those cases where information is available, these data are consistent with comparative plaque inhibitory findings for the products or their active ingredients. Again, it is concluded that the method is a useful screening and comparison test for the potential plaque inhibitory activity of antimicrobial oral hygiene products.

Adult

The antibacterial and anti-staining properties of the novel anti-adherent agent M239, 144 alone and in combination with chlorhexidine.

The anti-adherent agent M239,144 has been shown to reduce the adhesion of S. sanguis strains to saliva-coated hydroxyapatite by 27-94%. The purpose of this study was to determine any antibacterial properties of M239,144 which might inhibit replication of the organisms which do adhere and to determine whether M239,144 interferes with the antibacterial properties of the antiseptic agent chlorhexidine. Maximum inhibitory dilutions (MIDs) were calculated using both broth and agar methods. 0.1% M239,144 displayed no antibacterial activity against S. oralis NCTC 7864 or S. sanguis NCTC 7863 using the broth dilution method and had no antibacterial activity against a range of plaque-forming organisms using the agar dilution method. The anti-bacterial activity of chlorhexidine against four of five oral plaque-forming species was reduced by 0.1% M239,144. The effect of a novel anti-adherent agent, MK239,144, on chlorhexidine staining was assessed in an in vitro model. 1% M239,144 completely prevented chlorhexidine staining at concentrations from 0.0002% to 0.2%. M239,144/chlorhexidine formulations show potential for a non-staining anti-plaque mouthwash.

Anti-Bacterial Agents

A comparison of cetylpyridinium chloride, triclosan and chlorhexidine mouthrinse formulations for effects on plaque regrowth.

A relatively small number of agents are used in mouthrinse products, although the possible variability in the final formulations is enormous. The aim of this study was to compare equal concentrations of 3 antimicrobial agents, in simple formulations, for plaque inhibition. This 4-day plaque regrowth study was a 5-cell, randomised, double blind cross-over design, involving 20 healthy human volunteers. The mouthrinse formulations were aqueous 0.05% solutions of cetylpyridinium chloride (CPC), chlorhexidine and triclosan, together with a 0.1% CPC and a minus active control rinse. On Day 1, from a zero plaque baseline, volunteers ceased normal oral hygiene and rinsed 2x daily for 1 min. with 10-ml volumes of the allocated rinses. On Day 5, plaque was scored by index and area. All rinses produced lower mean plaque values compared to control, but unlike the CPC and chlorhexidine rinses, the differences with triclosan did not always reach significance. The CPC and chlorhexidine rinses were always significantly more effective than the triclosan rinse. The greatest plaque inhibition was with 0.1% CPC although rarely significantly greater than the 0.05% CPC and chlorhexidine rinses which were similar in efficacy. The results indicate that further studies on lower concentration chlorhexidine solutions are warranted.

Adult

Mouthrinses.

Mouthrinses have been used for centuries for medicinal and cosmetic purposes, but it is only in recent years that the rationale behind the use of the ingredients has been subject to scientific research and clinical trials. Although Listerine held its position for many years in the vanguard of the anti-plaque agents, the advent of mouthrinses containing chlorhexidine was a major breakthrough in the research for a chemical means to prevent disease. Since that time, and especially in the past ten years, the number of formulations that claim to have anti-plaque, anti-calculus, and anti-caries activity has increased, and much emphasis has been placed on such substances as an adjunct to, or indeed to replace, conventional toothbrushing techniques. This review covers the literature on mouthrinses over the past five years, concentrating more on the anti-plaque, anti-gingivitis, and anti-calculus formulations. In the first section, the methods of conducting clinical trials of mouthrinses are discussed, and a plea is made for a greater degree of standardization of methodology with agreed acceptable levels of clinical benefit. Trials of established mouthrinses are considered, and the advantages and disadvantages of several newer formulations discussed. From the review, it appears that chlorhexidine has no equal in its effects on reduction of plaque and gingivitis, but major drawbacks lie in the taste and stain-producing problems. The pre-brushing rinse, Plax, does not have unqualified success in all trials, though the more recent European formulation may have promise. Newer rinses which inhibit bacterial adhesion to tooth surfaces also appear promising, and it is suggested that more work on combinations of active ingredients is necessary.

Chlorhexidine

Efficacy of mouthrinses in inhibiting the development of supragingival plaque over a 4-day period of no oral hygiene.

This study was a first stage evaluation of the plaque inhibitory properties of an experimental cetylpyridinium chloride (CPC)/essential oil mouthrinse. The study was a formulation, not ingredient, evaluation and comparisons were made with established mouthrinse products. The 5 rinses tested were: the experimental formulation; a triclosan/copolymer prebrushing mouthrinse; two negative control rinses, which differed only in color; and as a positive control, a 0.2% chlorhexidine mouthrinse. The study used a 5 cell, 4-day plaque regrowth, double-blind crossover design in which 15 subjects participated. Allocation of mouthrinse sequences was accomplished using 3 replicates of a 5 x 5 Latin square, incorporating balance for carryover. On Day 1, subjects received a scaling and polishing to reduce plaque, ceased toothcleaning, and commenced rinsing twice daily, under supervision, with the randomly assigned rinse. Rinsing time for the experimental and one negative control rinse was 30 seconds and for the other rinses was 60 seconds. On Day 5, plaque was scored by both index and area. Differences in plaque regrowth between the rinse groups were highly significant. The order of efficacy from the most effective was: chlorhexidine rinse (positive control); experimental CPC/essential oil rinse; triclosan/copolymer rinse; and the negative control rinses. From the calculated confidence intervals each rinse differed significantly from each other rinse, except for the two negative control rinses which were comparable to each other. Proportionately, the CPC/essential oil rinse was positioned 30 to 50% between the triclosan/copolymer rinse and the chlorhexidine (positive control). These findings suggest that the CPC/phenolic rinse would seem worthy of further evaluation for adjunctive benefits to oral hygiene.

Adult

Dentine hypersensitivity: a clinical trial to compare 2 strontium densensitizing toothpastes with a conventional fluoride toothpaste.

A considerable number of varied agents are apparently effective in the treatment of dentine hypersensitivity. In particular, the literature supports the efficacy of fluoride and strontium containing formulations. Despite this, comparisons between strontium products are relatively few in number and surprisingly there are almost no evaluations of these products against "bench mark," conventional commercial fluoride toothpastes. This study was a double-blind parallel group comparison of two strontium-based desensitizing toothpaste products and a conventional fluoride product in the treatment of dentine hypersensitivity. A total of 119 patients completed the 12-week study and from them, sensitivity gradings were obtained at baseline, 1, 4, 8, and 12 weeks. Sensitivity was scored in response to cold air, a thermal probe at 0 degree C, and scratching with a dental probe. Patients also graded their overall sensitivity at each visit, using a visual analogue scale and the effects of treatment on completion. Plaque and gingivitis indices were recorded at each visit. There was an overall and progressive reduction in all sensitivity parameters in the 3 groups with no significant differences between the treatments. Plaque and gingivitis scores were already relatively low in this patient group at baseline but improved further as the study continued. The improvements, however, were comparable in the 3 groups. Under the conditions of this clinical trial the 2 desensitizing toothpastes showed similar reductions, but no greater than that observed in the conventional fluoride toothpaste. There is perhaps the need for further evaluations of desensitizing formulations using conventional fluoride products as controls rather than minus active or placebo formulations.

Adult

A study of a pre-brushing mouthrinse as an adjunct to oral hygiene.

A previous clinical screening study demonstrated that a cetylpyridinium chloride (CPC) essential oil mouthrinse inhibited plaque regrowth to a significantly greater extent than a negative control or a triclosan/copolymer rinse when used without toothbrushing. The purpose of this study was to evaluate the same ingredient combination as a pre-brushing rinse over a 6-week period. The study employed a 4 group parallel design with a minimum of 50 subjects per group. Subjects with a minimum baseline plaque index of 1.95 were recruited. The formulations employed were two variations of a CPC/essential oil rinse, a triclosan/copolymer product, and a hydroalcohol negative control. Subjects were rendered plaque free at baseline and then rinsed twice daily before toothbrushing with their allocated product. Plaque was scored at 6 days and 6 weeks. Plaque scores were reduced at 6 days compared to baseline but there were no significant differences between any of the groups. At 6 weeks, plaque scores were significantly lower in both CPC/essential oil groups compared to control. Although both CPC/essential oil groups showed plaque scores which were lower than the triclosan group, in only one of the groups was the difference significant. The triclosan product was not significantly different from control. The results support the previous findings that a CPC/essential oil rinse could be a useful adjunct to oral hygiene when used prior to normal toothbrushing.

Adolescent

Etiology, mechanisms, and management of dentine hypersensitivity.

Dentine hypersensitivity is a common painful condition of the teeth for which little is known of the etiology and predisposing factors. This tends to compromise management, and recurrence of the condition is frequent. Abrasive and erosive factors, by their effects on enamel and gingiva, are important in localizing sites of exposed dentine. Erosive agents are probably responsible for initiating sensitivity by opening dentinal tubules. Management should not only be treatment based. First, a differential diagnosis should be considered. Then, etiologic and predisposing factors should be identified and where possible removed, reduced, or modified. Treatments are largely aimed at blocking the hydrodynamic mechanism for stimulus transmission across dentine by occluding dentinal tubules. There is a need for further research into understanding the condition itself, its etiology, and the mode of action of the large number of varied but apparently effective therapeutic agents.

Dentin

Does gingivitis lead to periodontitis in young adults?

It has been assumed that poor oral hygiene predisposes to gingivitis with progression to periodontitis and tooth loss. However, a high prevalence of gingivitis occurs in some populations in which severe periodontitis is rare. To assess whether gingivitis is a reliable predictor of periodontitis, we compared the periodontal health of tea pickers and university students aged between 18 and 30 in Indonesia. Oral hygiene and gingival health was significantly better in students than in tea pickers. However, the prevalence and the severity of chronic periodontitis were similar in the two groups. Our findings suggest that gingivitis is a poor predictor of periodontitis in subjects younger than 30 years. Attempts to prevent periodontitis in young adults through antigingivitis measures such as plaque control may be unsuccessful.

Adolescent

A 6-month home usage trial of a 1% chlorhexidine toothpaste (1). Effects on plaque, gingivitis, calculus and toothstaining.

Research and development has been aimed towards the development of toothpastes for oral hygiene and gingival health benefits. The most effective antiplaque agent to date, chlorhexidine, is difficult to formulate into active toothpaste products. Despite some encouraging findings for experimental chlorhexidine toothpastes, there are to date no commercially available products. Based on positive findings from an experimental gingivitis study, this investigation evaluated 2 chlorhexidine toothpastes, one with fluoride, as adjuncts to oral hygiene. The study was a double-blind controlled, parallel, balanced group design, extending over 6 months. A total of 297 volunteers commenced the study after screening for a minimum acceptance level of gingivitis. At baseline, 6, 12 and 24 weeks, stain, gingival, bleeding and plaque indices were recorded, together with a calculus index at 6, 12 and 24 weeks. After a baseline prophylaxis, volunteers used the allocated product 2 x per day, with no other oral hygiene instructions given. Plaque, gingival and bleeding scores improved in all 3 groups, but to an overall significantly greater extent in the active groups. However, staining and calculus indices were significantly increased in the active compared to the control group. If the local side-effects of chlorhexidine are considered to be acceptable, these chlorhexidine toothpastes could be recommended for the same clinical applications as other chlorhexidine products. The apparent compatibility of fluoride with chlorhexidine in the one product may be pertinent to caries prevention.

Adolescent

A dose-response study of triclosan mouthrinses on plaque regrowth.

Triclosan is used in toothpastes and mouthrinses as a plaque inhibitory agent. The concentrations used and therefore the dose of triclosan varies between products and there is, as with most plaque inhibitory agents, little information on the dose response of this agent. The purpose of this investigation was to measure the plaque inhibitory properties of triclosan in a simple mouthrinse formulation over a range of concentrations and therefore doses. The study was a 5 treatment, double-blind, Latin-square randomised, minus-active controlled design balanced for residual effects. The formulations were 0.01%, 0.05%, 0.1% and 0.2% triclosan in 0.5% sodium carbonate and 5% alcohol aqueous solutions, used as 10 ml, 1-min rinses 2 x daily, without tooth-brushing. 2 groups each of 15 healthy volunteers rinsed during alternate 4-day treatment, 1-week washout periods with the allocated rinses. From a zero-plaque baseline on Day 1, plaque was scored by index and area on Day 5. A dose response pattern of decreasing plaque indices and particularly areas, with increasing triclosan dose was observed. However, by far the largest sequential drop in plaque scores occurred between 0.1% and 0.2% triclosan treatments. Extending the dose-response study to higher concentrations is considered impractical if not unjustifiable, because of potential harmful local side-effects and compliance difficulties. Dose-response studies to assess the agents thought to potentiate triclosan would seem warranted.

Adult

Evaluation of a mouthrinse containing chlorhexidine and fluoride as an adjunct to oral hygiene.

Chlorhexidine and fluoride have valuable preventive roles in dental and oral diseases. There is also evidence that in caries prevention, together, they provide additive benefits. However, combined chlorhexidine/fluoride formulations have rarely been evaluated. The aim of this study was to determine whether a 0.12% chlorhexidine, 100 ppm F- mouthrinse provided adjunctive oral hygiene benefits compared to a minus active control rinse. The study was a randomised double-blind parallel design involving 102 subjects of whom 99 completed the 6 week experimental period. Subjects rinsed 2x per day for 1 min with 15 ml of the allocated rinse. Normal toothbrushing procedures were maintained throughout the study. At 6 weeks, plaque and gingivitis scores were significantly lower and the incremental reduction significantly larger in the active rinse group. However, as expected, toothstaining was significantly increased with the active rinse. It is apparent that this chlorhexidine/fluoride rinse could be used in those regimens recommended for other chlorhexidine formulations. The value of the formulation in caries prevention would seem worthy of further investigation.

Adolescent

The effects of a chlorhexidine toothpaste on the development of plaque, gingivitis and tooth staining.

Chlorhexidine has found many uses in clinical dentistry as an antiplaque agent. To date, effective chlorhexidine-containing toothpastes have not been made available. This study was the first phase in the evaluation of a 1% chlorhexidine toothpaste, formulated to ensure a high availability of the contained antiseptic. The study was a 19-day, randomised double-blind placebo-controlled, crossover experiment al gingivitis clinical trial employing 14 healthy human volunteers. From a zero plaque and low gingivitis baseline, the development of plaque, gingivitis and dental staining was measured on days 12 and 19 of the 2 study periods. The toothpaste was used 2x a day as a slurry rinse with no other form of oral hygiene. The washout period was 21 days. The development of plaque and gingivitis was statistically and clinically highly significantly reduced during the use of the active compared to the placebo product. Conversely, dental staining was statistically and clinically significantly increased. The product deserves further evaluation for potential clinical use.

Adult

Dentine hypersensitivity: the measurement in vitro of streaming potentials with fluid flow across dentine and hydroxyapatite.

Stimulus transmission across dentine, in conditions such as dentine hypersensitivity, is considered to occur via a hydrodynamic mechanism. This fluid flow in dentine may then induce a mechanoreceptor response in pulpal nerves. However, when fluid flows through a porous structure electrical potentials are also generated. The aim of this study was to develop a reproducible model system to measure streaming potential across dentine and hydroxyapatite and determine the influence of pressure. Using an acrylic cell, with silver electrodes, streaming potentials were recorded across dimensionally standardized dentine and hydroxyapatite specimens, over a pressure range of 1-6 atmospheres. Streaming potentials were found to be directly proportional to pressure and dependent on the electrical conductivity of the saline used in the cell. The results confirm the limited existing data on streaming potentials across dentine and indicate that at these low pressures excitation of pulpal nerves would not occur. However, if, as may be the case, stimuli applied to dentine create very high pressures, the resultant potentials generated could indeed evoke a neural response. The model system is worthy of further use to study this phenomenon and the factors which may influence it.

Dentin

Dentine hypersensitivity--the effect of toothbrushing and dietary compounds on dentine in vitro: an SEM study.

Dentine hypersensitivity occurs when dentinal tubules are open on the dentine surface and patent to a vital pulp. There has been limited interest in the aetiology of dentine hypersensitivity. In particular, little is known about agents that remove the dentine smear layer to expose tubules. Toothbrushing certainly may expose dentine, but whether a toothbrush per se has the effect of opening tubules has not been established. The aim of this study in vitro was to determine whether a toothbrush could remove or create a smear layer. In addition, the combined effects of toothbrushing with dietary fluids on dentine was assessed. Toothbrushing was observed, by scanning electron microscopy, both to remove and to recreate a smear layer on dentine specimens. However, the processes took a considerable time, and under conditions of normal toothbrushing it is unlikely that the latter plays a direct aetiological role in opening tubules. Indeed, together with toothpaste it is more likely that brushing has a therapeutic action by mechanically forming a smear layer. Conversely, and importantly, toothbrushing in the presence of dietary acids enhanced smear layer removal. This finding raises the question of whether the dental profession should be advising that teeth be brushed before meals rather than after, as is often the case.

Acid Etching, Dental