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Biomedical subjects

M Addy

Publications and source records attributed to M Addy.

At least 199 records · Page 11Linked to original sources

The effects of a 0.2% chlorhexidine gluconate mouthrinse on plaque, toothstaining and candida in aphthous ulcer patients. A double-blind placebo-controlled cross-over study.

Despite the known effectiveness of 0.2% chlorhexidine gluconate mouthwash in preventing plaque formation, relatively few studies have assessed adjunctive benefit to normal unsupervised oral hygiene measures. Furthermore, there have been few accurate measurements of toothstaining in the presence of normal oral hygiene and little data of effects on oral candidal carriage. This study was a double-blind placebo-controlled cross-over study of a 0.2% chlorhexidine gluconate mouthwash used 3 times daily on plaque, staining and candidal carriage in a group of recurrent aphthous ulcer suffers who maintained normal oral hygiene measures. At the end of 2 6-week treatment periods, baseline plaque scores were reduced by active and placebo mouthwashes. Chlorhexidine significantly reduced plaque compared to the placebo. Staining has markedly and significantly increased during chlorhexidine rinsing. Candidal carriage was present in 22.2% of this group and there was no significant effect of chlorhexidine on the mean number of candidal colonies. The distribution of plaque and staining by tooth was plotted and observationally studied. Baseline and placebo treatment plaque distributions indicated the considerable relevance of toothbrushing behaviour for plaque distribution. The effects of toothbrushing on plaque distribution were minimised during the use of chlorhexidine. Staining associated with chlorhexidine showed a distribution again suggesting the influence of toothbrushing. In conclusion, chlorhexidine has significant adjunctive effects on plaque inhibition in the presence of normal unsupervised oral hygiene, but toothbrushing did not prevent toothstaining.

Adolescent↗

Dentine hypersensitivity. The effects in vitro of acids and dietary substances on root-planed and burred dentine.

Evidence indicates that teeth exhibiting cervical dentine hypersensitivity have open dentinal tubules at the dentine surface. The identification of factors which render dentine exposed and tubules open is important both to the prevention and management of dentine hypersensitivity. In this study, recently extracted teeth were root planed or burred to expose the root dentine. Specimens were horizontally sectioned and then using the apical portion as control, the coronal portions placed in a variety of strong and weak acids and dietary fluids. Examination under the scanning electron microscope revealed a smear layer covering completely underlying tubules on the control root planed or burred portions. Test portions exposed to strong and weak acids showed loss of the smear layer and exposure of large numbers of tubules. Formic and tannic acids produced no changes. Some dietary fluids, in particular red and white wine, citrus fruit juices, apple juice and yogurt produced similar etching effects to the acids. The low pH carbonated drink, coca-cola, and a blackcurrent cordial produced no effects. The results of this study in vitro cannot necessarily be extrapolated to the clinical situation, but suggest that certain dietary factors could play a rôle in the aetiology of dentine hypersensitivity. Dietary advice to patients may prove important in the management of this often recurrent condition.

Acids↗

Dentine hypersensitivity. A study of the patency of dentinal tubules in sensitive and non-sensitive cervical dentine.

Based on the hydrodynamic theory for stimulus transmission across dentine, it would be logical to conclude that teeth exhibiting the clinical symptoms referred to as dentine hypersensitivity should have dentinal tubules open at the root surface and patent to the pulp. With the exception of studies on cut dentine, there is little direct evidence to support this conclusion. In this study, caries-free teeth with exposed cervical root areas scheduled for extraction which were classified as non-sensitive or hypersensitive after suitable stimulation were examined by scanning electron microscopy. Hypersensitive teeth showed highly significantly increased numbers of tubules per unit area (approximately 8 X) compared with non-sensitive teeth. Tubule diameters were significantly wider (approximately 2 X) in hypersensitive compared to non-sensitive teeth. The number of teeth showing the penetration of methylene blue through the zone of exposed cervical dentine was larger and the depth of penetration greater in hypersensitive teeth compared to non-sensitive teeth. The results provide further evidence that stimulus transmission across dentine in hypersensitive teeth is mediated by a hydrodynamic mechanism. An understanding of factors which open dentinal tubules would seem important if attempts to prevent or treat dentine hypersensitivity are to be successful.

Dentin↗

A study of the association of fraenal attachment, lip coverage, and vestibular depth with plaque and gingivitis.

The effects of fraenal attachment, upper lip coverage, and mandibular vestibular depth on plaque and bleeding indices in the maxillary and mandibular anterior segments were studied in a group of 1015 school children aged 11.5 to 12.5 years. The position of the mandibular labial fraenum was relatively unimportant to plaque and mandibular gingivitis, but anterior fraenal attachment in the maxilla appeared to affect the retention of plaque and the degree of gingivitis. Maxillary and mandibular plaque and bleeding scores increased with decreasing upper lip coverage at rest. In the mandibular anterior segment, plaque and bleeding indices decreased with increasing vestibular depth. Further analysis demonstrated that fraenal attachment and vestibular depth and fraenal attachment and lip coverage were significantly associated. However, two-way analysis of variance indicated that the influence of fraenal attachment, vestibular depth, and lip coverage on plaque and gingivitis was independent. The influences of these soft tissue variables on plaque accumulation and gingivitis were of small clinical significance and not in themselves a justification for mucogingival surgery.

Child↗

A comparison of three delivery methods of chlorhexidine in handicapped children. I. Effects on plaque, gingivitis, and toothstaining.

In handicapped groups, the maintenance of oral hygiene can be a major problem, and chemical plaque control offers many advantages. This study compared the effectiveness of chlorhexidine gluconate, delivered as a 0.2% mouthrinse, a 0.2% spray, and a 1% gel in trays, in controlling dental plaque and gingival bleeding in a group of 49 spastic children. All three delivery methods produced an improvement in plaque and gingival bleeding scores. However, the gel was significantly more effective than either the mouthwash or the spray. There was no significant difference between delivery methods in the amount of tooth staining.

Administration, Topical↗

A comparison of three delivery methods of chlorhexidine in handicapped children. II. Parent and house-parent preferences.

As part of a study of chlorhexidine used for plaque control in handicapped children, preferences and difficulties with the three delivery methods were evaluated by questionnaire. The delivery methods were a 0.2% mouthwash, 0.2% spray, and 1% gel in trays. Responses from parents and house parents revealed the least preference for, and most difficulties with, the gel in trays. The spray was the most popular and 96% of the respondents would be prepared to use this indefinitely as a method of oral hygiene. The most effective method was the gel in trays, but results of the questionnaire suggested that the respondents would be unwilling to use it for prolonged periods. The importance of user acceptance and compliance to the long-term success of oral hygiene methods was evident.

Administration, Oral↗

Dentine hypersensitivity: effect of interactions between metal salts, fluoride and chlorhexidine on the uptake by dentine.

A large number of compounds may be applied to the teeth for preventive or therapeutic purposes, most notably in dentine hypersensitivity. The uptake of any one compound by tooth substances may clearly be affected by another to produce synergistic, additive or antagonistic effects. This study determined whether uptake interactions occurred between fluoride, chlorhexidine, strontium, tin and zinc. All compounds, in particular tin, showed considerable affinity for dentine. Fluoride reduced the uptake of zinc but not tin, strontium or chlorhexidine. Chlorhexidine increased the uptake of zinc, but not tin, strontium or fluoride. Zinc and tin decreased fluoride uptake but strontium had no such effect. Finally, chlorhexidine uptake was increased by zinc and tin but not by fluoride or strontium. Based on the theories proposed for the reaction of these various compounds with calcified tissues, explanations for the interactions can be made. The results appear relevant to some reported clinical effects of combinations of these compounds and indicate that such interactions may have advantageous or disadvantageous consequences depending on the basis for treatment.

Chlorhexidine↗

Chlorhexidine compared with other locally delivered antimicrobials. A short review.

Based on the association of bacterial plaque with the initiation of chronic gingivitis and progression of chronic periodontitis, chemical antiplaque agents have been employed both in prevention of periodontal disease and its treatment. In supragingival plaque control regimens, chlorhexidine has not been superceded as a chemical anti-plaque agent, although other compounds have been shown to be useful. The local side-effects of chlorhexidine and other cationic antiseptics, however, limit their long-term use for prevention. Extrinsic tooth staining in particular remains the greatest problem. Short-term anti-plaque uses for chlorhexidine include as an adjunct to mechanical cleaning in the initial oral hygiene phase of treatment, in situations where mechanical oral hygiene is difficult, including postsurgery, intermaxillary fixation, fixed orthodontic therapy, physically and mentally handicapped individuals, systemic diseases with oral manifestations such as leukaemia. More recent interest in chlorhexidine has resulted from the delivery of compounds subgingivally in the treatment of chronic periodontitis. Such methods have extended the use of chlorhexidine into areas inaccessible to the action of antimicrobial drugs delivered locally by conventional means, such as tooth brushing or mouth rinsing. Available evidence suggests that chlorhexidine may not be as effective as some antimicrobial drugs whose activity is more specific for those organisms considered particularly pathogenic to the periodontal tissues.

Anti-Bacterial Agents↗

Dental and social effects of malocclusion and effectiveness of orthodontic treatment: a strategy for investigation.

Study of the effectiveness of orthodontic treatment is complicated by a variety of factors, including the need for longitudinal, multidisciplinary appraisal and difficulties of randomisation, control and sample composition. This report outlines a recent initiative adopting a longitudinal, observational approach with a cohort of approximately 1000 12-yr-olds, selected by disproportionate stratified sampling in order that occlusal features of low prevalence, but high orthodontic interest, would be well represented. In the event, 4810 subjects were listed and after certain exclusions, 3420 children were screened. Using preselected screening criteria, 663 with specific occlusal features were selected and an additional 355 children with nonspecific features were randomly allocated on a pro-rata basis. This gave a final study population of 1018. Baseline dental data included the recording of caries, periodontal status and mandibular function. Study models were obtained and analysed using a new standardised technique for recording the alignment of individual teeth. Photographs of the face and dentition were collected and a rating system developed to score dental and facial attractiveness. Social-psychological data were recorded via self-rating questionnaires, interviews, parental questionnaires, teacher questionnaires and peer ratings.

Child↗

Prevalence of plaque, gingivitis and caries in 11-12-year-old children in South Wales.

The overall eruption and dental disease status of a group of 1015 11-12-yr-old schoolchildren in South Wales is presented. The mean number of teeth erupted was 21.8 with a distribution pattern reflecting continuing eruption of teeth at this age. Almost equal numbers of contralateral and opposing tooth types were present with exceptions including maxillary canines and lateral incisors. DMFT, DMFS, and DFS scores were consistent with other recent studies. The mean plaque score was 2.44 and showed a normal distribution for the group. All children had gingivitis at one or more sites as evidenced by bleeding on probing, and again the distribution pattern was a normal one. The mean pocketing was 1.24 mm and there was little clinical evidence of chronic periodontitis. As expected, plaque and gingivitis showed a very high and significant correlation, with plaque and pocketing and gingivitis and pocketing having lower correlation coefficients which were nevertheless highly significant.

Child↗

A study into the mucosal absorption of isosorbide dinitrate at different intraoral sites.

This study measured the absorption of isosorbide dinitrate (ISDN) into the systemic circulation after application of tablets to the buccal, palatal, or sublingual mucosa in six healthy subjects. After 1 minute serum levels were detectable by gas liquid chromatographic analysis from buccal and sublingual sites. Levels progressively increased, peaking at 5 minutes, and then progressively decreased during the 30-minute sampling period. At most of the time periods serum levels were greater from sublingual sites than from buccal sites. ISDN levels were not detected at any time in any subject after application to the palatal mucosa. As with the skin, the keratinized layer of the oral mucosa may be an important barrier to absorption. The findings appear relevant to the delivery of drugs via the oral mucosa for systemic effect.

Absorption↗

Evaluation of a method to study the uptake of prednisolone sodium phosphate from different oral mucosal sites.

A filter paper disk method for the delivery of drugs to oral mucosal sites was evaluated. The water-soluble steroid prednisolone sodium phosphate was chosen as the tracer drug. The in vitro recovery of the steroid from the filter paper disks after placement onto glass was greater than 95% and within the pipetting error for the method. Filter paper disks containing 1.25 mg doses of prednisolone sodium phosphate were placed on three different intraoral sites for 5 minutes and the drug retention was calculated in six volunteers. The mean percentage retention at the three sites was 65.4% for the sublingual mucosa, 24.1% for the buccal mucosa, and 9.9% for the palatal mucosa. The differences between the sites were all significant. The method may be useful for studying the retention of other drugs at various oral mucosal sites and for determining the factors that affect such retention.

Absorption↗

The pattern of adsorption of cationic antiseptics to polymethylmethacrylate.

Few studies have reported the maximum potential of surfaces to adsorb the cationic antiseptics and few comparisons between antiseptics have been carried out. The purpose of this investigation was to measure the maximum uptake of alexidine, cetyl pyridinium chloride, chlorhexidine gluconate and chlorhexidine acetate to polymethylmethacrylate and by the construction of adsorption isotherms determine the pattern of molecular attachment to the recipient surface. The mean maximum adsorption findings for these antiseptics demonstrated significantly greater uptake of cetyl pyridinium chloride than the other antiseptics and significantly less uptake of alexidine compared with the other antiseptics. All four antiseptics showed a Langmuir type adsorption isotherm consistent with the formation of a monolayer of molecules on the recipient surface. For chlorhexidine preliminary studies demonstrated that the pattern of adsorption was not altered by saliva pre-treatment of surfaces. No evidence of molecular multilayering was observed even at higher concentrations of the antiseptics. However, the maximum uptake on to the surface was significantly increased when no post-treatment washings were carried out. It was concluded that this increased uptake would be unlikely to play an important role in antiplaque activity because of its relative instability. The pH dependency for the adsorption of these antiseptics was demonstrated such that as previously observed for chlorhexidine gluconate at low pH adsorption is almost completely, or completely, prevented.

Adsorption↗