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Biomedical subjects

M Addy

Publications and source records attributed to M Addy.

285 records · Page 16Linked to original sources
PubMedDate not supplied

Effect of time on the remineralisation of enamel by synthetic saliva after citric acid erosion.

The aim of this in vitro study was to determine the influence of remineralisation time on rehardening of surface-softened enamel after citric acid erosion. Seven groups of 13 samples of human enamel were eroded in 0.3% citric acid at pH 3.2 for 2 h followed by profilometric measurements. Individual groups of specimens were placed in artificial saliva for 1, 2, 4, 6, 9 or 24 h. A control group was placed in isotonic saline for 24 h. After new profilometric measurements samples were ultrasonicated stepwise up to 480 s with profilometric measurements performed at 5, 30, 120, 240 and 480 s to measure the depth of surface softening. The control group had a softened surface layer of mean thickness 2.9 microm. Mineral deposition was seen at all remineralisation times by scanning electron microscopy. Exposure to artificial saliva for 1, 2 or 4 h produced a partial rehardening of the softened enamel; the additional surface losses produced by ultrasonication were lower and time delayed compared to the control group. Specimens remineralised for 6, 9 and 24 h showed little evidence of surface loss after ultrasonication. The data suggest that a complete rehardening of the softened enamel in vitro is reached after a remineralisation time of 6 h. These data are of clinical relevance to tooth wear. However, there is a need for studies in situ of enamel demineralisation and remineralisation.

Analysis of Variance↗
PubMedDate not supplied

Further modification to soft drinks to minimise erosion. A study in situ.

Soft drinks have been successfully modified to reduce enamel erosion. The aim of this study was to further modify an original low erosive blackcurrant drink product by the addition of a gum, to manipulate more favourably other drink parameters. The study was a single-blind, randomised four treatment crossover design involving 12 healthy volunteers. During 10 working-day study periods, subjects wore enamel samples in the mid palatal region of a removable appliance. Specimens were taped to expose a 2-mm enamel window. The drinks under test were: (1) Orange juice, (2) Original blackcurrant drink, (3) Water, and (4) Experimental blackcurrant drink. Drinks were imbibed at 250-ml volumes 4 times a day during appliance wearing from 09.00 to 17.00. Appliances were removed at lunchtime. Measurements of specimens were made at baseline, 2, 5 and 10 days using a profilometer. One 5-day and one 10-day specimen from each subject during each treatment were ultrasonicated. Significant differences, in erosion between drinks, were seen at days 5 and 10. Comparisons of preselected pairs of drinks of interest showed significantly reduced erosion by the two blackcurrant drinks compared to orange juice with no significant differences from water. The original blackcurrant drink produced significantly less erosion than the experimental drink. Ultrasonication removed enamel from the Orange juice specimens but very little from those exposed to water and the two blackcurrant drinks. Extrapolating the effects of both blackcurrant drinks suggested that alone they should not cause significant clinical erosion in a lifetime's intake of 1 litre per day.

Adult↗
PubMedDate not supplied

Resurgence of malaria in Calcutta in 1995: a hospital based study.

A total of 405 cases of fever who were either admitted to the Hospital or attended in paediatric out patient Department or Emergency of Medical College Hospital, Calcutta between January '95 and November '95 were included in the study. Majority of cases presented with usual features of malaria like fever with chill and rigor, hepatosplenomegaly, pallor. Apart from these, complicated manifestations like shock, convulsion D.I.C and jaundice were also observed. Some unusual presentations with severe diarrhoea, dehydration and features like that of acute viral respiratory tract infection were highly confusing in terms of clinical diagnosis. P. falciparum was observed in 35.5% of cases. Overall therapeutic response to chloroquin was good, However, two patients died of cerebral Malaria. Five cases of severe malaria were caused by P. vivax however, other etiological features could not be found to attribute the severe nature of these illnesses.

Animals↗
PubMedDate not supplied

Taurolin as an oral rinse. I. Antimicrobial effects in vitro and in vivo.

Taurolin, a synthetic antimicrobial agent, has been suggested to be of potential value as an inhibitor of dental plaque. Although data on the antibacterial activity of Taurolin are available there is a dearth of information for effects on oral bacterial isolates and antibacterial activity in the mouth. This study assessed the in vivo and in vitro antibacterial properties of a Taurolin rinse by a) determining the MID values against seven oral isolates and b) measuring salivary bacterial counts following a single rinse. By comparing activity with chlorhexidine, it was hoped to determine substantivity and predict the relative ability of Taurolin to inhibit plaque through an antimicrobial effect. For Taurolin, MID values against the test organisms were found to range between 1:20 and 1:80, while for chlorhexidine, values between 1:320 to 1:640 were obtained. The effects on salivary bacterial counts revealed that Taurolin significantly reduced salivary bacterial counts compared to saline up to 5 hours post rinsing, but was significantly less effective than chlorhexidine after 30 minutes and up to 7 hours. Results indicate that Taurolin has some persistence of antimicrobial activity in the mouth. This suggests that Taurolin would possess some plaque inhibitory properties albeit less than chlorhexidine. These conclusions were confirmed in a subsequent investigation.

Adult↗
PubMedDate not supplied

Taurolin as an oral rinse. II. Effects on in vitro and in vivo plaque regrowth.

A Taurolin solution has been shown previously to possess antibacterial activity, not only by a bactericidal effect but also by reducing bacterial surface adherence. Such mechanisms may contribute to reduction in dental plaque in the mouth, however this remains to be determined. The present study assessed whether a Taurolin rinse could firstly effect bacterial surface growth and, secondly, whether the same rinse could reduce plaque regrowth over a 4-day period. The findings showed that the Taurolin reduced in vitro bacterial surface growth and in vivo plaque regrowth compared to saline, but was not as effective as a chlorhexidine rinse. The findings suggest Taurolin would probably have a moderate effect on plaque and gingivitis in longer-term use.

Analysis of Variance↗
PubMedDate not supplied

Comparison of an herbal toothpaste with a fluoride toothpaste on plaque and gingivitis.

An herbal/bicarbonate toothpaste has received some attention from the public and profession following a number of studies which have reported beneficial effects of the paste on both plaque and gingivitis. The present study, one of several ongoing clinical trials, evaluated the toothpaste in mouthrinse form using a 19-day, no oral hygiene, triple-crossover design in which it was compared with a commercial fluoride toothpaste rinse and the antiplaque mouthrinse chlorhexidine. Over the three periods of the study an increase in plaque and gingivitis was seen for all three products. However, while significant reductions in both parameters were seen with chlorhexidine compared to the toothpastes, there were no significant differences between the herbal and fluoride toothpaste. From these findings it can be concluded that in the long term, the herbal/bicarbonate toothpaste may not exert significant therapeutic effects on plaque and gingivitis beyond that of a conventional commercial paste. Nevertheless, where there is a demand for a natural product, the herbal/bicarbonate paste may be a worthwhile alternative.

Adult↗
PubMedDate not supplied

A comparison of 0.12% and 0.1% chlorhexidine mouthrinses on the development of plaque and gingivitis.

A number of commercially prepared chlorhexidine mouthrinses which are now available are formulated at concentrations lower than the more usual 0.2%. This study compared 0.12% and 0.1% chlorhexidine mouthrinses for effects on plaque regrowth and gingivitis, using a two 19-day period single-operator blind-crossover study design on 14 healthy human volunteers. The 0.12% rinse was a commercial product previously shown as effective as a 0.2% rinse. The 0.1% rinse was a reformulated version of a 0.1% preparation commercially available at the time of this study. Plaque reformation was recorded on days 12 and 19 by score and area. Gingivitis was recorded at day 1, 12 and 19 by measuring gingival crevicular fluid, gingival index and bleeding on probing. The mouthrinses were used twice a day and as recommended by the manufacturer. Mean scores for plaque and gingivitis were mostly lower with the 0.12% rinse but only reached significance for plaque score on days 12 and 19 and for plaque area on day 19. Reformulation of the 0.1% would appear to have markedly improved the antiplaque properties to levels similar to a known effective commercially available 0.12% rinse.

Adult↗
PubMedDate not supplied

Comparison of a phenolic and a 0.2% chlorhexidine mouthwash on the development of plaque and gingivitis.

Chlorhexidine and phenolic mouthrinses have attracted considerable interest as adjuncts to oral hygiene. The aim of this study was to compare two well known proprietary mouthrinse products for their effects on plaque regrowth, the development of gingivitis and the formation of toothstaining. The study was a single-blind, randomized, placebo-controlled, triple cross-over experimental, gingivitis design. A group of 15 volunteers with a very high standard of oral hygiene and gingival health used each rinse for 19 days in the absence of normal toothcleaning. Each period was separated by a 21 day washout. Plaque scores were significantly different between the rinses, being lowest with chlorhexidine and highest with saline. The plaque area increased 3-fold with the phenolic rinse and 6-fold with the saline rinse compared to the chlorhexidine rinse. Similarly, gingivitis increments were lowest with chlorhexidine and highest with saline but differences between rinses did not reach significance. Staining was significantly different between rinses, primarily due to minimal staining associated with the saline rinse. Staining occurred with both the chlorhexidine and phenolic mouthrinses. It is concluded that the 0.2% chlorhexidine rinse offers greater oral hygiene benefits than the phenolic rinse. The question of indications and durations of use of mouthwash products should be addressed.

Adult↗
PubMedDate not supplied

Effect of plaque of five toothpastes used in the treatment of dentin hypersensitivity.

During a study to assess the efficacy of five toothpastes in the treatment of dentin hypersensitivity, the plaque scores of patients were recorded at baseline, 2, 4, and 6 weeks treatment and 6 weeks post-treatment visits. Baseline buccal and lingual plaque indexes were found comparable between the groups and the mean buccal plaque scores were considered low by normal standards. During the use of the three experimental silica-based pastes, one containing strontium acetate, one strontium acetate and MFP and a commercially available formaldehyde-containing paste, plaque scores fell significantly and to a similar extent in all four groups. After cessation of treatment at 6 weeks, plaque scores had increased back to baseline in all groups. During the use of a diatomaceous earth/strontium chloride toothpaste, commercially available, plaque scores increased significantly, both from baseline and by comparison with the other four pastes. Nevertheless, plaque scores in this group returned to baseline levels after cessation of treatment and a return to use of a conventional non-desensitizing toothpaste. The effects of all but the diatomaceous earth/strontium chloride toothpaste would not be inconsistent with previous experience in toothbrushing studies where patients are monitored regularly. The effects on plaque did not necessarily coincide with the previously reported treatment benefit of the respective products in dentin hypersensitivity.

Adult↗
PubMedDate not supplied

Chewing sticks versus toothbrushes in West Africa. A pilot study.

Chewing sticks are used for tooth cleaning by many populations. Despite the fact that they contain antimicrobial substances that could conceivably benefit oral hygiene, there have been few attempts to evaluate properties in vivo. This pilot, cross-sectional study recorded the oral hygiene and gingival health of adult Ghanaens who used chewing sticks, toothbrushes, or a combination of both for tooth cleaning. Plaque and gingivitis scores were higher in the chewing stick users, although these were primarily due to differences in men. Men had poorer oral hygiene and gingival health than women, irrespective of the oral hygiene regimen. The same differences were apparent for city and rural dwellers, with no overall differences observed between these two groups. The longer time that is necessary for cleaning with chewing sticks may explain the apparent reduced cleaning efficiency in men. The antimicrobial substances contained in chewing sticks appear to provide no additional benefits to those produced by the antimicrobial activity of commercially available toothpastes.

Adult↗
PubMedDate not supplied

Comparison of two commercially available chlorhexidine mouthrinses: I. Staining and antimicrobial effects in vitro.

Several commercially produced chlorhexidine rinses are now available. These formulations vary in concentration and recommended regimens of use. One formulation, a 0.1% chlorhexidine rinse, anecdotally has been reported to not produce the characteristic dental staining. The aim of this study was to compare the 0.1% formulation with a 0.2% commercially produced chlorhexidine rinse for staining and antimicrobial effects in vitro. Tea staining of tooth and acrylic specimens exposed to the two rinses at various dilutions was measured over a 5-day period. Minimum inhibitory dilutions of each product against standard test bacteria were determined by agar dilution. The 0.1% product produced no staining of specimens greater than that noted with controls. At equivalent concentrations, the 0.2% product produced heavy staining of specimens. The antimicrobial effect of the two products was similar but the overall profile for the 0.1% preparation suggested activity derived from ingredients other than chlorhexidine. The results suggest that the chlorhexidine in the 0.1% rinse was partly or completely inactivated and, although staining may not occur in vivo, the formulation would have a much reduced antiplaque action.

Chlorhexidine↗
PubMedDate not supplied

Comparison of two commercially available chlorhexidine mouthrinses: II. Effects on plaque reformation, gingivitis, and tooth staining.

Several chlorhexidine mouthwashes are now produced commercially but which differ in concentration and regimen of use. This study compared a 0.1% formulation with a 0.2% formulation for effects on plaque reformation, development of gingivitis, and tooth staining. The investigation was a single blind cross-over design employing 14 volunteers with a high standard of oral hygiene and gingival health. The rinses were used twice a day during two 19 day periods using the regiments recommended by each manufacturer and as a replacement for mechanical oral hygiene practices. A baseline zero plaque score was obtained at the beginning of each period with a 16-day washout allowed between the two periods. Parameters of gingival inflammation were scored at baseline and then, together with plaque and tooth stain scores, at 12 and 19 days. All indices of gingival inflammation and plaque were significantly increased at days 12 and 19 with the 0.1% mouthwash formulation. Little evidence of tooth staining was noted with the 0.1% formulation. The 0.2% mouthwash produced the characteristic staining noted with most chlorhexidine preparations. Based on the findings of this study and a previous laboratory investigation, it is concluded that the reduced antiplaque activity of the 0.1% formulation resulted from inactivation of chlorhexidine within the product rather than from the reduced dose of chlorhexidine used.

Adult↗