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Biomedical subjects

M Addy

Publications and source records attributed to M Addy.

At least 163 records · Page 9Linked to original sources

Toothpastes containing 0.3% and 0.5% triclosan. I. Effects on 4-day plaque regrowth.

Triclosan has been added to toothpaste formulations, alone or with zinc salts, to reduce plaque regrowth. The most encouraging results have been obtained with triclosan/zinc formulations particularly at the higher concentrations of one or both agents. Formulations containing 0.2% triclosan alone have shown less promise and the aim of this study was to measure plaque regrowth over 4-day periods with the use of 0.3% and 0.5% triclosan toothpastes with and without the addition of a copolymer, polyvinyl methyl ether maleic acid (PVM/MA) and to compare the findings with a conventional fluoride/anionic detergent based toothpaste and a 0.2% chlorhexidine mouthrinse. The method was a no oral hygiene randomized 6 times crossover study using the toothpaste slurry rinsing method. Plaque was recorded by a plaque index and by area. Three of the four triclosan toothpastes reduced plaque regrowth significantly compared with the placebo, with no significant differences among the triclosan toothpastes. Plaque scores were always significantly lower with the chlorhexidine mouthwash compared to all toothpastes. The results suggest that at 0.3% to 0.5% triclosan alone or with a copolymer toothpaste may be a benefit to oral hygiene, but whether this is sufficient to affect gingival health requires further clinical evaluation. Further research would also appear indicated to determine optimal levels for the copolymer concentrations in toothpastes.

Adult↗

Toothpastes containing 0.3% and 0.5% triclosan. II. Effects of single brushings on salivary bacterial counts.

For antimicrobials such as chlorhexidine antiplaque activity appears due to persistence of considerable antimicrobial action in the mouth. The substantivity of antimicrobial compounds can be evaluated by measuring the magnitude and duration of salivary bacterial counts following a single exposure. Such data has been shown to correlate with plaque inhibitory properties of antimicrobial compounds. This study measured the effects of single brushings with 0.3% and 0.5% triclosan with or without PVM/MA copolymer in toothpastes on salivary bacterial counts in 14 young adults. The results were compared with single rinsing with a 0.2% chlorhexidine solution, water and a single brushing with a commercial fluoride toothpaste. The study was a 7 cell cross-over design, randomized using a 7x7 latin square design. Chlorhexidine produced large and significant reductions which persisted to the 7 hour measurement time with no indication of count recovery at this time. The triclosan pastes containing the copolymer produced significant reductions which did not persist beyond 5 hours and evidence of bacterial count recovery with a paste containing triclosan but no copolymer (increments) was apparent after 30 minutes. The water and control paste produced no significant effects on counts. Intertreatment comparisons showed the chlorhexidine rinse more effective than all other preparations in all time periods. Some of the triclosan toothpastes containing the copolymer produced significantly greater effects compared to water or the control paste at some, but not all time periods. There was little difference between the triclosan pastes with the copolymer. Nevertheless, the duration and magnitude of salivary bacterial count reductions seen with the triclosan toothpastes may explain the plaque inhibition effect.

Adult↗

The relationship of anterior overjet to plaque and gingivitis in children.

The aim of the present investigation was to evaluate the relationship of overjet to periodontal status. Detailed examinations of occlusal and periodontal characteristics were completed on 914 12-year-old children. Plaque indices, bleeding indices, and anterior overjet were recorded for each incisor tooth. There was a significant association between mean plaque scores and the extremes of overjet measurement, suggesting that tooth cleaning is more difficult in these cases. Also, it was apparent that for right-handed children, the plaque and gingivitis scores were lower on the left side of the mouth.

Child↗

Dentine hypersensitivity. I. Effects produced by the uptake in vitro of metal ions, fluoride and formaldehyde onto dentine.

Dentine has been shown to possess affinity for a large number of varied compounds, many of which have been shown effective in clinical trials, for the treatment of dentine hypersensitivity. The mode of action of these compounds is unclear. The aim of this study was to investigate the uptake of metal ions, fluoride and formaldehyde in solution onto dentine in vitro and determine whether therapeutic effects could be mediated through occlusion of dentinal tubules. Etched dentine sections were exposed for 1 h to 1000 ppm solutions of fluoride and metal salts. Levels of fluoride and respective metals could be extracted and measured from the specimens. Saliva pretreatment had a variable but small effect on uptake of each ion, but post treatment washings reduced all levels of retained fluoride and metals. X-ray microanalysis indicated surface or immediate subsurface deposits of metals. However, surface changes were only consistently produced by zinc and more particularly tin salts. Both zinc and tin salts produced covering or obturation of tubules. The surface effects of zinc could largely be reversed by washing, but not those of tin. Formaldehyde alone or in the presence of saliva produced no effects. A 4-week study involving twice daily exposure of specimens to saliva and fluoride, metals or formaldehyde yielded essentially the same results. It is unlikely that, except for tin, the compounds tested achieve their apparent clinical effects mediated by direct occlusion of dentinal tubules.

Calcium↗

The antibacterial effect of toothpastes on the salivary flora.

Both past and presently available toothpastes contain potential antimicrobial agents which could have a beneficial effect in the prevention of plaque and gingivitis. If these preparations were to be effective clinically, some effect on salivary bacteria would also be expected. This cross-over study measured salivary bacterial counts and the presence or absence of residual antibacterial activity in saliva following tooth brushing with 7 commercially available toothpastes, and moreover, compared their effect with that produced by a chlorhexidine gel. Generally, all toothpaste products produced a reduction in aerobic, anaerobic and streptococcal counts with a hexetidine containing toothpaste producing the largest and longest lasting reduction. In contrast, an enzyme containing toothpaste and an amine fluoride toothpaste, had little effect on bacterial counts. The chlorhexidine gel produced the largest reduction in salivary counts, which was evident for at least 5 h following brushing. Residual antibacterial activity in saliva was only evident immediately following brushing with the hexetidine toothpaste, but for the chlorhexidine gel, was present up to 90 min following brushing. The findings of this study have illustrated the limited antibacterial activity of presently available toothpastes on the salivary flora compared to chlorhexidine, and as such, would tend to question the relative benefit of toothpaste in preventing periodontal disease through an antimicrobial effect.

Adult↗

The mechanism of action of chlorhexidine. A study of plaque growth on enamel inserts in vivo.

Controversy exists concerning the mode of action of chlorhexidine in plaque inhibition. This study attempted to determine whether an oral reservoir of chlorhexidine was necessary for plaque inhibition. Plaque growth on enamel under the influence of topically applied or rinsed chlorhexidine was closely monitored by clinical scoring, bacterial culturing and scanning electron microscopy. Thus, 3 subjects wore removable acrylic appliances containing enamel inserts. In the first regimen, inserts on one side of the appliances were exposed to 0.2% chlorhexidine and on the other, water for 1 min twice a day for 14 days. In the second regimen, subjects rinsed with 0.2% chlorhexidine for 1 min twice a day for 14 days with the appliances in situ. Results demonstrated that plaque growth assessed by the 3 study methods was very small on chlorhexidine-treated inserts by comparison with water-treated specimens. Importantly, inserts treated with chlorhexidine topically or by rinsing could not be distinguished by any method of evaluation. It is concluded that chlorhexidine achieves plaque inhibition as a result of an immediate bactericidal action during the time of application and a prolonged bacteriostatic action as a result of adsorption to the pellicle coated enamel surface. Consistent with other clinical studies, it is apparent that a progressively desorbing oral reservoir of antiseptic is not the mechanism by which chlorhexidine achieves plaque inhibition on teeth.

Administration, Topical↗

A clinical trial to assess the efficacy of sanguinarine-zinc mouthrinse (Veadent) compared with chlorhexidine mouthrinse (Corsodyl).

A single-blind crossover study was used to compare the ability of a 0.2% chlorhexidine mouthrinse (Corsodyl) with a sanguinarine-zinc mouthrinse (Veadent) to inhibit plaque and gingivitis. 14 volunteers starting with plaque-free mouths and optimal gingival health, rinsed with the preparations over two 19-day periods whilst refraining from all other oral hygiene procedures. At days 8, 15 and 19 of the trial, Corsodyl was significantly more effective at inhibiting both plaque and gingivitis. The findings of this study would suggest that the Veadent mouthrinse would at most only have a limited rôle as an inhibitor of plaque and gingivitis.

Adult↗

Use of antimicrobial containing acrylic strips in the treatment of chronic periodontal disease. A three month follow-up study.

Local antimicrobial therapy has been considered for use in the treatment of chronic periodontal disease. This study evaluated chlorhexidine, metronidazole, and tetracycline delivered into periodontal pockets in an acrylic resin vehicle and compared the results with root planed and untreated sites over a three-month follow-up period. One site per patient where pocketing greater than or equal to 6 mm associated with a single rooted tooth was randomly allocated to one of the five possible regimens. Baseline and follow-up measurements included probing depth, loss of attachment, bleeding on probing, crevicular fluid flow, and dark-field microscopy of a subgingival plaque sample. Intratreatment evaluations revealed no significant changes in any parameter for untreated sites. Significant improvements in many parameters occurred with all four therapies although the magnitude and duration were greater in metronidazole and root planing groups. The more important intertreatment comparisons indicated that most treatments produced significant benefits compared with the control group; however, again these were greater with metronidazole and root planing. Furthermore, significantly greater effects were noted for metronidazole and root planing compared with tetracycline and more particularly chlorhexidine. It is concluded that some locally delivered antimicrobials alone may be useful in the treatment of chronic periodontal disease. However, at this time local antimicrobial therapy should be considered as adjunctive to conventional debridement techniques.

Adult↗