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Biomedical subjects

M Addy

Publications and source records attributed to M Addy.

At least 253 records · Page 14Linked to original sources

Comparison of the in vivo and in vitro antibacterial properties of antiseptic mouthrinses containing chlorhexidine, alexidine, cetyl pyridinium chloride and hexetidine. Relevance to mode of action.

A study was carried out to compare the antibacterial properties of four cationic antiseptics, three of which are available as commercial mouthrinse preparations. Minimum inhibitory concentrations for alexidine, cetyl pyridinium chloride, chlorhexidine gluconate and hexetidine against a range of standard test organisms, were determined by tube dilution. Similar values for Oxford staphylococcus were then obtained in Dubos medium to which protein as yeast, or food extract, or serum was added in doubling dilutions to 16%. Salivary bacterial counts after a single rinse with the antiseptics or water throughout the day were measured in 10 subjects together with the duration of any residual antiseptic activity in the saliva. All antiseptics were effective at low concentrations against the organisms tested but the minimum inhibitory concentration values for hexetidine were the highest. Food extract and serum markedly increased the minimum inhibitory concentration values of all antiseptics, although alexidine and hexetidine were the least affected in percentage terms. The activity of a 1% povidone iodine preparation, used for comparison, was almost completely vitiated. An immediate significant fall in salivary bacterial counts was produced by the cationic antiseptics. Return to pre-rinse levels was seen for hexetidine after 90 min, cetyl pyridinium chloride after 3 hours, alexidine after 5 hours and chlorhexidine gluconate after 7 hours. Residual salivary antibacterial activity remained to 90 min for cetyl pyridinium chloride, to 3 hours for hexetidine and alexidine and to 5 hours for chlorhexidine gluconate. The antibacterial properties measured, in particular the duration of effect in vivo, may be relevant to the anti-plaque activity of cationic antiseptics.

Bacteria↗

The use of polymethylmethacrylate to compare the adsorption and staining reactions of some cationic antiseptics.

This study assessed the value of acrylic, in powder and optically clear forms, to measure the adsorption and staining properties of some cationic antiseptics. The uptake of chlorhexidine gluconate, chlorhexidine acetate, alexidine and cetyl pyridinium chloride onto acrylic powder was measured spectrophotometrically. Similarly, tea staining of perspex blocks exposed twice daily to the antiseptics and hexetidine, was measured over a 5 day period. The adsorption of chlorhexidine gluconate and acetate was similar and greater than alexidine but less than cetyl pyridinium chloride. Desorption of the adsorbed antiseptics was minimal after 48 hours soaking in water. Acid produced a variable desorption of antiseptics. Tea staining of blocks was significantly greater with antiseptic treated specimens compared to control specimens. However, staining resulting from alexidine was greater than cetyl pyridinium chloride which was greater than chlorhexidine. Hexetidine produced the least staining. Saliva treatment of specimens only increased the tea staining of control blocks. The results indicated that adsorption levels alone would not explain the differences in antiplaque and staining activity reported for the cationic antiseptics.

Adsorption↗

Effects of a zinc citrate mouthwash on dental plaque and salivary bacteria.

A double-blind crossover trial was carried out to assess the effect of zinc citrate on plaque accumulation in vivo and to measure total salivary aerobes and anaerobes both during the trial and throughout the day following a single rinse. When compared to the placebo, zinc citrate significantly reduced the plaque accumulation in the subjects. However, the mean reduction was small and of questionable clinical importance. A progressive increase in plaque was observed throughout both active and placebo 7-day rinsing periods. There was no significant reduction in salivary bacterial counts either during the crossover study or during the day following a single rinse with zinc citrate.

Bacteria↗

Dental and social effects of malocclusion and effectivenessof orthodontic treatment: a review.

The relationship between malocclusion and the health of the masticatory apparatus is reviewed. While there is evidence that certain features such as traumatic deep overbite, unprotected incisors and impacted teeth may adversely affect the longevity of the dentition, the relationship of dental irregularity to periodontal disease, caries and mandibular dysfunction is less certain. Studies in the field of social psychology indicate that an unattractive physical appearance may evoke an unfavourable social response in many facets of social interaction but the place of dentofacial anomalies in this context has not been satisfactorily assessed. The individual's adjustment to his own imperfections in dental alignment is variable and there is no evidence that children with visible irregulaities will in general be emotionally handicapped. Effectiveness studies have yet to be undertaken but the factors which will have to be taken into account in assessing the benefits of orthodontic treatment are the definition of treatment need, treatment standards, the disadvantages of treatment and the influence of other determinants of dental health. The need for further research is underlined.

Dental Caries↗

Light microscopic and color television image analysis of the development of staining on chlorhexidine-treated surfaces.

Tooth staining with the use of chlorhexidine preparations is the major problem of long term application. Evidence suggests that the staining arises from a cationic/anionic interacation of chlorhexidine with components of certain dietary materials. The purpose of this in vitro study was to compare visually the development of tea and coffee staining on acrylic and tooth specimens treated with chlorhexidine and to follow the development of tea staining on perspex by light microscopy and color television image analysis. All specimens were maintained in their respective beverage for 5 days with test specimens removed three times a day and placed for 2 minutes in an 0.2% chlorhexidine solution. Both test tooth and acrylic specimens showed comparably and markedly increased staining by the beverages compared with control specimens. Color television image analysis of test specimens demonstrated more marked and rapid development of tea staining when studied on a daily basis. Microscopic examination revealed the staining to be made up of small particles of material which increased in size and coalesced with time. Again, marked differences were apparent in the stain on test and control specimens. The results of this in vitro method provided further evidence for a dietary aetiology to chlorhexidine staining and were consistent with clinical findings. Such a method may be useful to assess staining arising from the use of other anti-plaque agents.

Acrylic Resins↗

Use of chlorhexidine gluconate and povidone iodine mouthwashes in the treatment of acute ulcerative gingivitis.

A trial was conducted to compare the effectiveness of povidone iodine and chlorhexidine gluconate with buffered peroxyborate in the treatment of acute ulcerative gingivitis. After 20 patients had entered the trial and 11 had required additional therapy with metronidazole to control their symptoms, the study was terminated. Those patients receiving peroxyborate all showed a satisfactory improvement in clinical signs and symptoms. One patient each receiving povidone iodine or chlorhexidine reported a symptomatic improvement, although gingival ulceration was still apparent at 1 week. The remaining patients all required metronidazole therapy to control their symptoms. Povidone iodine and chlorhexidine gluconate therefore cannot be recommended for the treatment of acute ulcerative gingivitis.

Acute Disease↗

Comparison of the in vivo and in vitro antibacterial properties of providone iodine and chlorhexidine gluconate mouthrinses.

Clinical and laboratory studies were carried out to compare the antibacterial properties of two antiseptic mouthwashes, namely 1% povidone iodine and 0.2% chlorhexidine gluconate. In a group of 10 subjects after a single rinse with povidone iodine, an immediate mean fall in total salivary aerobes and anaerobes occurred, followed by a return to normal levels by 1-hour postrinsing. With chlorhexidine gluconate a similar but greater reduction in salivary bacterial counts was observed, which was still present up to the 7-h postrinsing period. Saliva samples obtained from the subjects 2 min after rinsing with providone iodine produced little or no inhibition to the growth of a test organism in vitro, whereas following chlorhexidine gluconate, antibacterial activity was present in the saliva specimens up to the 3-h sampling time. Using culture media containing comparable levels of soluble protein to saliva, the minimum inhibitory concentrations of povidone iodine against several standard test organisms were much higher than those of chlorhexidine gluconate. The results suggest that povidone iodine, as a mouthwash, exerts only an immediate antibacterial effect and unlike chlorhexidine, is not retained at antibacterial levels within the oral cavity after expectoration. This lack of prolonged action of povidone iodine in the oral cavity would appear to be relevant to its reported lack of antiplaque activity.

Anti-Infective Agents, Local↗

A comparison of a periodontal dressing and chlorhexidine gluconate mouthwash after the internal bevelled flap procedure.

A group of 15 patients requiring comparable bilateral internal bevelled flap procedures took part in a study to compare the clinical results achieved when a dressing or chlorhexidine mouthwash was used during the first postoperative week. Initial preoperative conditions were comparable. At the end of the first postoperative week, significantly more plaque accumulated and the sulcus bleeding index was significantly higher on the dressing treated side. At 1 month and 3 months postoperatively the sulcus bleeding indices were below preoperative levels for both treated sides with no significant differences between the sides. A significant and comparable reduction in pocket depths occurred following the two postoperative treatments. Subjectively recorded pain scores demonstrated that more pain was experienced on the dressing treated side, particularly during the first 4 postoperative days. More patients preferred the mouthwash as a postoperative treatment.

Adult↗

Hibitane in the treatment of aphthous ulceration.

In the absence of a known aetiology the management of recurrent aphthous ulceration is symptomatic with the removal of predisposing factors where possible. Since the severity and duration of ulcers may be increased by bacterial contamination, the effect of chlorhexidine gluconate in mouthwash and gel forms on the natural history of the condition has been studied. The mouthwash study employed a 0.2% chlorhexidine gluconate solution, a 0.5% astringent solution and a control mouthwash. Each mouthwash was used by all of the patients, with 5 ml of each preparation being diluted with 5 ml of water for use three times a day. The gel study employed a 1% chlorhexidine gluconate and a placebo gel with approximately a 1 inch of the gel from the tubes being placed in the mouth three times a day. Both studies were carried out in the double-blind crossover manner with each preparation used for 5 weeks with a 2-week interval between preparations. In the mouthwash trial chlorhexidine gluconate significantly reduced the incidence, duration and severity of ulcers, whereas in the gel trial chlorhexidine significantly reduced the severity and duration but not the incidence of ulceration. Since the dosage regimes for chlorhexidine in the two studies were comparable, the mode of delivery would appear to be important in the therapeutic effectiveness.

Biguanides↗

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↗