Biomedical subjects

M Addy

Publications and source records attributed to M Addy.

At least 55 records · Page 3Linked to original sources

PubMed1995

Evaluation of clinical trials of agents and procedures to prevent caries and periodontal disease: choosing products and recommending procedures.

The prevention of caries, gingivitis and periodontal diseases has been, and still is, a major objective for the dental profession. A large number of products are available to the general public, either over the counter or on prescription, formulated to prevent these diseases. Formulations are also used by professionals for the prevention and treatment of dental diseases. In recommending or using agents for prevention or therapy it is necessary for the practitioner to appreciate whether proof of efficacy is established. Preventive or therapeutic roles of formulations are frequently confused and there is a need to define the often misleading terminology used to describe products. Guidelines are required to enable the dental professional to understand research data and what constitutes proof of efficacy for preventive and/or therapeutic formulations. The guidelines should describe the research methodologies used today, including study design and analysis, ethics, the format of research papers and the relevance of laboratory data to clinical efficacy.

Anti-Infective Agents, Local↗

PubMed1995

Pathogenicity of Artyfechinostomum oraoni in naturally infected pigs.

In an attempt to establish the diarrhoeogenic potential of the newly identified Artyfechinostomum oraoni, which was associated with human diarrhoea in a tribal community near Calcutta, India, two naturally infected domestic pigs of the locality were followed in captivity. Both pigs developed fatal diarrhoea after 5 months. The autopsy revealed a massive infection with the echinostome on a haemorrhagic and oedematous mucosa of the jejunum and duodenum extending up to pyloric end of the stomach. It is suggested that similar pathology might also be operating in the infected man.

Animals↗

PubMed1995

Studies on the life cycle of Artyfechinostomum oraoni Bandyopadhyay, Manna & Nandy 1989: embryogenesis & development in the intermediate host.

A study was undertaken to elucidate the life cycle of the parasite A.oraoni, isolated from man. For the purpose, operculated eggs were isolated from faeces of oraon tribals belonging to the village Bandipore, district North 24-Parganas of West Bengal province of India. The purified eggs were incubated at different temperatures, salinity and pH. Larvae (miracidia) could be observed to develop between the 7th and 8th day of incubation at a temperature range between 22 degrees-30 degrees C. While the optimum pH was observed to be neutral, larval development did not take place at salinity beyond 0.8 per cent. To identify the correct intermediate host, all available species of snails from the study village were colonised and infected with the laboratory hatched miracidia from human derived operculated eggs. It was observed that of all the snails infected, only Lymnaea supported the development of rediae from miracidia, which could be observed on the 32nd post infection day. Considering the results of the experimental study, it was hypothesised that Lymnaea spp. of snails under natural condition also, might act as the first intermediate host for A. oraoni.

Animals↗

PubMed1995

A comparative study of stain removal with two electric toothbrushes and a manual brush.

Recent studies have suggested that a sonic electric toothbrush is more effective than a manual brush at removing extrinsic dental stain. There have been few studies of the comparative stain removal properties of different electric brushes. The study reported here was conducted to compare the efficacy of the sonic toothbrush (Sonicare) with an oscillating/rotating brush (Braun Oral-B Plaque Remover) and a conventional manual brush (Crest Complete). The study was a single-blind, randomized, cross-over design, balanced for residual effects and employing 24 subjects. Stain was enhanced over a 21-day period by twice-daily rinses with chlorhexidine and frequent intakes of tea and/or coffee. At the end of each period, tooth stain intensity and area, tongue stain intensity and area, lower lingual calculus and subjective tooth sensitivity were recorded together with preference for the brushes determined at the study's completion. Similar levels of tongue staining were recorded for the three periods, with no significant differences between the three groups. Tooth stain intensity, for most sites, was not significantly different between the three groups. For mean total stain area and for lingual and lingual interproximal sites, a significant reduction in stain was seen following use of the oscillating/rotating brush compared to the manual brush. The reductions in stain with the sonic brush were not significantly different from the manual brush. With the exception of maximum stain intensity, there were no significant differences between the oscillating/rotating and sonic brushes. Significantly less tooth sensitivity was found following use of the oscillating/rotating brush compared to both the manual and sonic brushes. All three brushes were found to be safe, but volunteer preference significantly and predominantly favored the oscillating/rotating brush. The results suggest that the oscillating/rotating brush is superior to a manual brush for stain removal.

Adult↗

PubMed1994

Aetiological, predisposing and environmental factors in dentine hypersensitivity.

If the hydrodynamic theory of stimulus transmission across dentine is valid, sensitive dentine has tubules open at the surface and patent to the pulp. Direct and indirect evidence supports this supposition. Factors that result in dentine exposure remove the covering enamel or periodontal tissues (gingival recession). Epidemiological and clinical data for the distribution of exposed cervical dentine indicate that chronic trauma from physical and chemical factors is the most significant aetiological factor. Brushing with a toothpaste may not open dentinal tubules. It is more likely that toothpaste ingredients, when brushed on dentine, would create a smear layer. Exposure of tubules by erosion is probably the major initiator of sensitivity. An increase in our understanding of the aetiological factors involved in dentine hypersensitivity is essential if a sound approach to its management is to evolve. Such information could emanate from epidemiological studies, clinical investigations and laboratory experiments.

Beverages↗

PubMed1994

An 8-year study of changes in oral hygiene and periodontal health during adolescence.

This study reports data collected from a cohort of 405 South Wales adolescents examined at the ages of 11-12, 15-16 and 19-20 years. Dental plaque and gingivitis scores decreased markedly between the ages of 11-12 and 15-16 years, and to a lesser extent between 15-16 and 19-20 years. There was a decrease in the mean depth of the gingival sulcus between the ages of 11-12 and 15-16 years, perhaps reflecting a decrease in false pocketing and gingival oedema associated with puberty and tooth eruption. Conversely, there was an increase in the mean depth of the gingival sulcus between the ages of 15-16 and 19-20 years, possibly indicating the initiation of periodontal breakdown and the appearance of true pocketing. Gender was found to be an important determinant of the level of oral hygiene practised, the boys having consistently poorer oral hygiene than did the girls. At the commencement of adolescence this was not reflected in higher gingivitis scores, but by the age of 15-16 years the boys exhibited significantly more gingivitis than did the girls.

Adolescent↗

PubMed1994

Dose response of chlorhexidine against plaque and comparison with triclosan.

The optimum dose of chlorhexidine delivered by mouthrinse, which balances efficacy against local side-effects, is generally considered to be in the region of 20 mg 2 x daily. Unfortunately, there have been few dose-response studies for chlorhexidine mouthrinses and for these, only limited details are published. The aims of this study were to determine the dose response of chlorhexidine to plaque inhibition and position a 0.1% triclosan rinse within this model. 28 subjects took part in this 7-treatment, double-blind, randomised cross-over 4-day plaque regrowth study. The rinses were 0.01%, 0.05%, 0.1% and 0.2% chlorhexidine, 0.1% triclosan and minus active controls for chlorhexidine and triclosan. On day 1 from a zero plaque baseline, volunteers suspended tooth-cleaning and commenced supervised 2 x daily rinsing with 10 ml volumes of the allocated rinses. On Day 5, plaque was scored by index and area. Treatment differences between the 7 rinses were highly significant. A clear dose-response pattern was seen for chlorhexidine with mean plaque scores decreasing with increasing dose. Even at 0.01%, chlorhexidine showed considerable and significant plaque inhibition compared to control. Triclosan at 0.1% showed limited plaque inhibition and less than 0.01% chlorhexidine. The findings of this study suggest that consideration could be given to low concentration chlorhexidine rinses as adjuncts to oral hygiene.

Adult↗

PubMed1994

Comparison of 2 chlorhexidine mouthwashes on plaque regrowth in vivo and dietary staining in vitro.

Until recently, the few available chlorhexidine mouthrinse products have been 0.2% formulations. However, concentrations of 0.12% chlorhexidine appear as effective as 0.2%, if the volume of the rinse is increased to 15 ml. Since the mere incorporation of chlorhexidine in a formulation does not guarantee availability of the antiseptic, it would seem reasonable to evaluate or compare all products. This is particularly the case when other ingredients, such as fluoride are added. The 1st study compared the effect of a 0.12% chlorhexidine rinse with a 0.12% chlorhexidine/0.022% sodium fluoride rinse for effects on plaque regrowth. The study was a 7-day, blind, randomised, 2-cell cross-over design with a baseline control run in period, in which 18 subjects participated. Both chlorhexidine products significantly reduced plaque compared to control but the chlorhexidine fluoride rinse was less effective than the chlorhexidine only rinse. The 2nd study assessed the propensity of the chlorhexidine rinses to induce dietary staining in vitro. For the chlorhexidine fluoride rinse, this was less than the other 0.12% rinse and a commonly used 0.2% product. The data in vivo and in vitro suggest reduced chlorhexidine availability from the chlorhexidine fluoride product which appears to cause some loss of efficacy.

Chlorhexidine↗

PubMed1994

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↗

PubMed1994

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↗

PubMed1994

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↗

PubMed1994

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↗

PubMed1994

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↗

PubMed1994

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↗

PubMed1994

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↗

PubMed1994

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↗

PubMed1994

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↗

PubMed1993

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↗