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Biomedical subjects

M Addy

Publications and source records attributed to M Addy.

At least 271 records · Page 15Linked to original sources
PubMed1977

The effect of partial dentures and chlorhexidine gluconate gel on plaque accumulation in the absence of oral hygiene.

A study was made of the effect of wearing partial dentures upon plaque accumulation in a group of 24 partial denture wearers, when oral hygiene procedures were withdrawn. The modifying effect of a 1% chlorhexidine gluconate gel on this plaque accumulation was measured. Plaque accumulation was measured at the end of four different denture-wearing regimens each 3 days in length. The wearing of a partial denture either day only or day and night, significantly increased plaque accumulation over not wearing a denture. There was no significant difference between plaque accumulation with day wear and day and night wear. The increase in plaque accumulation with day and night wear resulted from an equal and significant increase in both buccal and lingual plaque accumulation. Chlorhexidine gluconate in the form of a gel significantly reduced plaque accumulation during daytime wear. These results tend to confirm that plaque control is a major factor in determining the long-term effects of partial dentures upon the periodontal structures and emphasize the importance of oral hygiene in partial denture wearers.

Adult↗
PubMed1977

Effectiveness of methods of teaching dental health to 9- to 10-year-old schoolchildren in the United Kingdom.

Dental health education employing five different teaching methods was given to classes of 9- to 10-year-old schoolchildren. A control class received no teaching. The dental health knowledge of the classes was assessed before teaching, and immediately, 1 week and 3 months after teaching by the use of a questionnaire. All methods resulted in a variable increase in marks immediately after teaching. This was followed by a fall in marks for each class over the 3-month period. The poster and pack methods of presenting information, overall, had little or no effect on the recall of information. The talk, visual aids and project methods all significantly increased dental health knowledge for the 3-month period.

Audiovisual Aids↗
PubMed1977

The effect of povidone iodine on plaque and salivary bacteria. A double-blind crossover trial.

A double blind crossover trial was carried out to assess the effect of povidone iodine on plaque accumulation in vivo and to measure the total salivary aerobes and anaerobes throughout the study. When compared to the placebo preparation, povidone iodine was without effect on plaque accumulation in all the subjects and there was a progressive increase in plaque throughout the 10-day periods. A 30 to 40 % overall reduction in aerobes and anaerobes occurred with the active preparation which was significant. There appears to be no indication for the use of povidone iodine as an adjunct to oral hygiene or in the treatment of chronic gingivitis.

Bacteria↗
PubMed1976

The use of chlorhexidine mouthwash compared with a periodontal dressing following the gingivectomy procedure.

The clinical results achieved were compared when a group of 21 patients requiring gingivectomies in comparable bilateral segments received a dressing or a chlorhexidine mouthwash during the first post-operative week. Initial pre-operative conditions were comparable. In each of the two treatments highly significant reductions in pocket depths were achieved; the sizes of the reductions were of clinical significance (greater than 1.5 mm). The observed difference (0.16 mm) between the two treatments in favour of the mouthwash, although significant at the conventional 5% level, was clinically unimportant. More patients preferred the dressing as a post-operative treatment, and the clinical implications of the patients' preferences are discussed.

Adult↗
PubMed1975

A chlorhexidine-containing methacrylic gel as a periodontal dressing.

The modification of a methacrylic gel for use as a periodontal dressing was attempted. The increased adhesion and rigidity of the resultant material appeared consistent with the clinical findings. Satisfactory retention of the dressing was found in 85% of those placed on a group of patients attending for periodontal surgery. The potential value of the methacrylic gel for carrying and releasing pharmacological agents useful in the management of lesions of the oral mucosa was assessed by incorporating chlorhexidine acetate into the dressing. In vitro and in vivo studies demonstrated effective release of the chlorhexidine from the dressing throughout the period of time a periodontal dressing is normally in situ. In conclusion the results suggested that the modified methacrylic gel fulfills the requirements of a periodontal dressing. Study to assess further the potential for this material to carry other pharmacological agents used in the topical treatment of lesions of the oral mucosa is indicated.

Acrylates↗
PubMedDate not supplied

The formation of stain on acrylic surfaces by the interaction of cationic antiseptic mouthwashes and tea.

Clinical and in vitro studies have implicated dietary components as major aetiological factors in staining of teeth and acrylic materials associated with chlorhexidine use, a local side effect not unique to this antiseptic. These experiments studied the precipitation and surface staining reactions of the cationic antiseptics alexidine, cetyl pyridinium chloride (CPC), chlorhexidine, and hexetidine, with the beverage tea. All of the antiseptics precipitated a standard tea solution and for alexidine and chlorhexidine acetate and gluconate, this was at concentrations greater than 100 mumol/L, for hexetidine greater than 200 mumol/L, and for CPC greater than 400 mumol/L. With the exception of CPC precipitation was reduced with decreasing pH and for chlorhexidine was inhibited below pH 3. The addition of polymethylmethacrylate (PMMA) to the antiseptic solutions increased the precipitation concentrations by an amount calculated to be adsorbed by polymer. Acrylic blocks treated with equimolar solutions of the antiseptics became progressively and significantly more stained by tea than control specimens over a 5-day period. Alexidine induced significantly greater staining and hexetidine significantly less than the other antiseptics. Staining was pH dependent and significantly reduced as the pH decreased. Both stain and precipitates were insoluble in strong acids and alkalis. It is concluded that staining observed clinically may represent a precipitation reaction with the complexing of antiseptics with dietary chromogenic material.

Acrylates↗
PubMedDate not supplied

Hexetidine mouthrinse in the management of minor aphthous ulceration and as an adjunct to oral hygiene.

A number of compounds have been used in the management of recurrent oral ulceration, including antimicrobials. This was a double-blind placebo-controlled cross-over study to assess the value of a 0.1% hexetidine mouthwash in the management of minor aphthous ulceration and as an adjunct to oral hygiene. Forty patients with a catalogued history of ulceration took part. Patients were randomly allocated to active/placebo or vice versa order of mouthwashes, which were used as 15 ml volumes three times a day. Treatment periods were 6 weeks with a 3 week washout. During each period patients kept daily records of the number, site, and duration of ulcers, together with pain scores. Plaque and gingivitis were scored at baseline and end of treatment periods. Thirty-eight patients completed the study, with no significant treatment differences between active and placebo rinses on any ulcer parameter. Additionally, the hexetidine rinse provided no significant benefit to oral hygiene or gingival health. However, there was a significant period effect, with considerable ulcer improvements during the second period, irrespective of treatment. In conclusion, the hexetidine rinse appeared to offer no benefits to these patients, but professional supervision of ulcer treatment does appear to result in a worthwhile placebo effect.

Adolescent↗
PubMedDate not supplied

Oral health in the terminally ill: a cross-sectional pilot survey.

This study of 20 hospice patients provided baseline information on oral and dental status in the terminally ill. For each patient, a questionnaire was completed, the mouth was examined, and an oral rinse and imprint cultures were collected to establish the prevalence and intra-oral density of yeasts, staphylococci and coliforms. Oral symptoms reported included disturbance of taste (26%), dysphagia (37%), soreness (42%), and dryness (58%). Of the 75% who wore dentures, 71% had difficulty with their prosthesis (es). A clinical diagnosis of oral candidiasis was made in 70% of subjects. The high prevalence of oral symptoms, denture problems, and candidiasis clearly affect the quality of remaining life in terminally ill patients.

Candidiasis, Oral↗
PubMedDate not supplied

Ultrasonication as a method to study enamel demineralisation during acid erosion.

The aim of this study was to use ultrasonication as a method to measure subsurface demineralisation of enamel. Polished human enamel samples with surface profiles within +/-0.3 microm were divided into 6 groups of 10 specimens. The groups of specimens were exposed to 0. 3% citric acid (pH 3.2) for 30 min, 1, 2, 3 or 4 h. The depths of the resulting lesions were measured using a profilometer. A control group was stored in water for 4 h. Ultrasonication in water was performed on the specimen groups for 5, 30, 120, 240 and 480 s with profilometric measurements at each time point. The depth of the erosion increased linearly with the exposure time. Most of the additional loss of enamel occurred with the 5-second ultrasonication. The 30-min and 1-hour erosion lesions were further deepened by approximately 1 microm with 5 s of ultrasonication. The 2-, 3- and 4-hour lesions were deepened by 2-4 microm with 5 s of ultrasonication. There were no changes in the control group. It is concluded that ultrasonication removed softened enamel from the surface of the eroded enamel. Ultrasonication together with accurate measurement of lesion depth by profilometry offers a useful method for studying the depth of enamel softening associated with erosion.

Analysis of Variance↗
PubMedDate not supplied

The use of ultrasonication to study remineralisation of eroded enamel.

The aim of this study was to use ultrasonication and profilometry as methods to study de- and remineralisation of citric acid-eroded enamel at different pH values. Seventy-eight polished human enamel samples were divided into three test and three control groups of 13 specimens each. Three specimens of each group were chosen for SEM examination. The samples were exposed to 0.3% citric acid at pH 2.54, 3.2 or 4.5 for 2 h. The depths of the resulting lesions were measured by profilometry. The test groups were placed in artificial saliva and the control groups were stored in saline (0.9% NaCl) for 24 h and new profiles recorded. Finally all specimens were ultrasonicated in water for 5, 30, 120, 240 and 480 s with profilometric measurements at each time point. Ultrasonication of the test groups after remineralisation showed little effect on the lesion depth, whereas the control groups had an enamel loss of 2.1 microm at pH 2.54, 2.9 microm at pH 3.2 and 0.4 microm at pH 4.5 after 30-second ultrasonication. These differences from respective test groups were statistically significant at pH 2.54 and 3.2 but not at pH 4.5. Ultrasonication of control pH 2.54 and 3.2 specimens removed an amorphous covering layer to reveal a flattened surface with prisms outlined by prism boundaries. It can be concluded that remineralisation in artificial saliva stabilises the surface softened enamel against ultrasonication.

Analysis of Variance↗
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↗