PubMed Health⌕ Search

Biomedical subjects

M Addy

Publications and source records attributed to M Addy.

At least 289 records · Page 16Linked to original sources
PubMed1983

Subgingival metronidazole in acrylic resin vs. chlorhexidine irrigation in the control of chronic periodontitis.

After initial scaling, root planing and cleaning of subcontact areas, chronic periodontitis patients received oral hygiene instruction consisting of Bass toothbrushing using a sodium fluoride toothpaste, but without stress on interdental cleaning. They were then assigned to two groups, one of which self-administered 0.2% chlorhexidine solution subgingivally, once daily for 4 weeks, while the other was subjected to subgingival application of acrylic resin strips containing 40% metronidazole once weekly for 4 weeks. Plaque Index, Sulcus Bleeding Index, probeable pocket depth and gingival shrinkage were assessed for this treatment period and for a further 8 weeks. Highly significant improvements compared with baseline values were achieved and maintained to the end of the study. There were no significant differences between the groups at any time, except for Sulcus Bleeding Index which at Days 56 and 84 showed metronidazole to be superior. It was concluded that the regimens selected were equally effective in improving periodontal health over a 3-month period.

Acrylic Resins↗
PubMed1983

Host preference of Phlebotomus argentipes in different biotopes.

A study on host preference of P. argentipes in two different biotopes was conducted by capturing the flies from cowsheds and human dwellings. The human blood index of P. argentipes collected from cowsheds was 21.5% and 69.6% when collected from human dwellings; this indicates that host preference of P. argentipes varies widely in different biotopes.

Animals↗
PubMed1982

In vitro studies into the release of chlorhexidine acetate, prednisolone sodium phosphate, and prednisolone alcohol from cold cure denture base acrylic.

An investigation was carried out into the release of chlorhexidine acetate, prednisolone sodium phosphate, and prednisolone alcohol from a cold cured acrylic denture base material. The drugs were added at 10% w/w with the powder phase of the material. Water, at the concentrations of 10%, 20%, and 30% of the monomer phase of the material was added to chlorhexidine-containing and chlorhexidine-free samples. Spectrophotometric and bioassay measurements of the release of chlorhexidine demonstrated protracted delivery to 140 days. The daily release rate was increased by the addition of water to the material and at 30% water incorporation the release was greater and increased up to 190 days. The release pattern of prednisolone sodium phosphate was similar to that of chlorhexidine without the addition of water. Prednisolone alcohol was released for a much shorter period and at lower levels. Scanning electron microscopic examination of the polished, etched, and fractured surfaces of the material demonstrated that chlorhexidine acetate and prednisolone sodium phosphate were incorporated into the interbead matrix areas of the material. The irregularities in the material increased with the addition of water. Prednisolone alcohol produced minimal changes in the specimens except after soaking in water for 140 days when numerous small defects could be seen in the matrix zones at high magnification. The use of materials such as water to increase porosity appears a simple method of improving the release pattern of drugs from acrylic. However, the strength of the resulting material would require support from an existing intraoral prosthesis or appliance.

Acrylic Resins↗
PubMed1982

The effect of single morning and evening rinses of chlorhexidine on the development of tooth staining and plaque accumulation. A blind cross-over trial.

A dietary aetiology for tooth staining associated with the use of chlorhexidine has been postulated. The time related activity of chlorhexidine would therefore suggest that evening rinsing would result in less staining than morning rinsing. This study measured tooth and tongue staining and plaque accumulation in a group of 18 volunteers, rinsing once at night or once in the morning with chlorhexidine in a blind cross-over design. Beverage intake during two 10-day periods was prescribed. Significantly more tooth staining, but not tongue staining, was seen with morning rinsing. Plaque accumulation showed a trend to more plaque with morning rinsing, which was not significant. The findings would be consistent with a dietary aetiology for tooth staining. However, these results emphasise the considerable duration of activity of chlorhexidine on surfaces in the oral cavity and the theory of progressive desorption of chlorhexidine from the tooth surface is questioned.

Adult↗
PubMed1982

Effects of sugared and sugar-free chewing gum on the accumulation of plaque and debris on the teeth.

The aim of this study was to determine the effects of sugar-free and sugar-containing gums on plaque formation, established plaque and salivary debris. Plaque accumulating during three 5-day periods was recorded in a group of 10 students who, in the absence of normal oral hygiene methods, chewed sugar-free or sugar-containing chewing gum or did not chew gum. In a second group of 10 students the effect of chewing the two types of gum on 3-day accumulations of plaque was recorded. Finally, the wet weight of liquorice debris present in saliva with and without gum chewing, was recorded. During the no chewing periods distinct and significant differences in the amounts of plaque accumulating at different sites were apparent. Both types of chewing gum significantly and comparably reduced plaque accumulation during the 5-day period. The chewing gums also significantly reduced established plaque on many tooth surfaces. Salivary debris was significantly reduced by 50% after chewing gum. It was noted that plaque removal occurred primarily from sites remote from the gingival margin and interdental areas and therefore it was concluded that the observed effects of chewing gum on plaque would not be reflected in a reduction in gingival inflammation.

Adult↗
PubMed1982

The effect of orthodontic appliances on the distribution of Candida and plaque in adolescents.

The site prevalence and intra-oral density of Candidal organisms may be increased by local factors including prostheses. However, whether significant changes in Candidal carriage occurs with denture wearing is not clearly established. This study employed the imprint culture technique to assess the effects of fixed and removable orthodontic appliances on oral carriage, site prevalence and intra-oral density of Candida in adolescents. Moreover, alterations in plaque distribution were measured. Groups of 12-16 year olds without or wearing fixed and removable appliances were studied. Imprint cultures were taken from six intra-oral sites and colony counts recorded after 48 hours incubation on selective media. Plaque scores were recorded from non-appliance and removable appliance wearers. The prevalence of Candidal carriage in the groups was not significantly different being 46 per cent of non-appliance, 51 per cent of fixed appliance and 52 per cent of removable appliance wearers. However, the prevalence of Candidal recovery at some sites and Candidal densities at all sites were significantly increased in both fixed and removable appliance wearers. Thus orthodontic appliances may predispose to Candidal proliferation in oral carriers. However, the results do not permit the conclusion that appliances may change non-carriers of Candida to carriers. Plaque distribution was significantly altered in removable appliance wearers when compared with non-appliance wearers as a result of increases in palatal plaque scores. These findings again emphasize the particular need for oral hygiene instruction in patients wearing appliances or partial prostheses.

Adolescent↗
PubMed1982

The development and in vitro evaluation of acrylic strips and dialysis tubing for local drug delivery.

This study reports on the development of drug containing acrylic strips for delivering antimicrobial agents and compares the in vitro release pattern with dialysis tubing. Polyethylmethacrylic strips of suitable dimensions containing 10 to 50% chlorhexidine acetate, 40% metronidazole and 40% tetracycline were prepared. Daily release of the incorporated drugs into 1 ml aliquots was measured spectrophotometrically over a 14 day period. Similarly the release of chlorhexidine gluconate from various lengths of patent and heat sealed dialysis tubing was recorded for 4 days. At 30%, 40% and 50% admixtures the acrylic strips released chlorhexidine up to the 14 day period and a parallel bioassay confirmed the maintenance of antibacterial activity to this time. At the same admixture the release of metronidazole was greater than chlorhexidine and tetracycline. All drugs were released at high levels on day 1 followed by a marked fall in release by day 2 and progressive fall thereafter. The release from tubing was almost total within 24 hours and was independent of sealing the ends. The strips appear to have potential for prolonged drug delivery to periodontal pockets. Preliminary clinical use revealed no patient acceptability problems and alterations in subgingival flora were produced.

Chlorhexidine↗
PubMed1982

Comparison of hypertonic saline and chlorhexidine mouthrinses after the inverse bevel flap procedure.

THE VALUE OF periodontal dressings after periodontal surgery has been questioned. This study further evaluated chlorhexidine as a possible alternative. A group of nine patients requiring comparable bilateral inverse bevel flap procedures underwent preoperative oral hygiene instruction and scaling. Immediately before surgery and up to 3 months postoperatively, clinical records of plaque index, pocket depths and sulcus bleeding index were made. Records were taken of patients' postoperative discomfort and preferences. During the 1st postoperative week either a 0.2% chlorhexidine gluconate or a 1% saline mouthrinse was prescribed. Plaque accumulation and sulcus bleeding were significantly reduced on the sides treated with chlorhexidine. Significant reductions in pocket depths were recorded for both groups but there were not differences between treatments. Less postoperative discomfort was experienced with chlorhexidine, although the difference was not significant. Five patients preferred chlorhexidine, one saline, and three had no preferences. These and previous results suggest that a periodontal dressing is unnecessary or even undesirable after the inverse bevel flap procedure, and may be usefully replaced by a suitable antiplaque agent.

Adult↗
PubMed1981

Stridor.

Explore the source record for details and available documents.

Child↗
PubMed1981

The effects of drug and water incorporation upon some physical properties of cold cured acrylic.

The addition of drugs to the cold cured acrylics has been demonstrated to variably affect their mechanical properties. This study investigated the effects, to the mechanical properties of a cold cured denture base material, of the addition of drugs and water. Chlorhexidine acetate was incorporated into the denture reline material at 10% w/w in the polymer phase of the material. Specimens also contained 10, 20, or 30% water w/w in the monomer phase of the material with or without the drug. The hardness of the specimens decreased with the addition of water to drug containing or drug-free specimens. Furthermore, there was a significant reduction in the modulus of elasticity of the material with the addition of drugs and water or water alone, which was progressive as the amount of water increased. The load at fracture was similarly reduced as the water incorporation increased. The results demonstrated the considerable effects drug and water incorporation had upon the material. However, this would not negate the use of the material in the oral cavity in the reline or rebase situation employing existing prostheses. Moreover, the reduction in material strength may have the advantage of progressive loss of material with a resulting improved release pattern of the contained drug.

Chemical Phenomena↗
PubMed1981

In vitro studies into the use of denture base and soft liner materials as carriers for drugs in the mouth.

The potential of plasticized and polymerized acrylics to carry and release medicaments was investigated. Chlorhexidine acetate was incorporated at concentrations of 2, 5 and 10% into the powder phase of heat and cold cured acrylics and an acrylic gel soft liner. A preliminary bioassay demonstrated comparable release at anti-bacterial levels from all three materials. Spectrophotometric and agar diffusion measurements of the chlorhexidine released into water showed the duration increased with the concentration of chlorhexidine incorporated. At 10% admixture the release from the polymerized and plasticized acrylics was in excess of 100 days. Light and scanning electron microscopy of polished and fractured surfaces of the polymerized acrylic showed the chlorhexidine distributed throughout the matrix of the materials. Following soaking in water, holes appeared in the matrix, particularly in the surface zones. Sections of the acrylic gel soft liner demonstrated chlorhexidine distributed as particulate material. Soaking in water caused vacuolation of the material and at higher concentrations material break-up was apparent.

Acrylates↗
PubMed1981

The effects of the incorporation of chlorhexidine acetate on some physical properties of polymerized and plasticized acrylics.

The effects on the water uptake and weight loss of the incorporation of chlorhexidine acetate in heat cured acrylic and an acrylic gel soft liner was determined. Hardness and transverse bend measurement were similarly made for admixtures to heat and cold cured acrylics. Following soaking in water for 87 days the heat cured test specimens demonstrated an initial weight gain followed by a progressive loss, the soft liner test specimens however all showed weight gains. Drying back specimens to constant weight revealed significantly greater weight losses in test compared to control specimens for both the cured acrylic and gel liner. However these weight losses were less than the chlorhexidine content for 5 and 10% admixtures. Hardness and moduli of elasticity measurements were significantly reduced for heat and cold cured acrylics containing chlorhexidine. The property changes observed in the materials would be consistent with the pattern of incorporation of chlorhexidine into the matrix. However, these do not negate the carriage of medicaments in these materials for prolonged delivery within the oral cavity, if employed as rebase or reline materials in existing prostheses.

Acrylates↗
PubMed1981

Effects of malalignment of teeth in the anterior segments on plaque accumulation.

The importance of malposition of teeth and plaque accumulation is still not established. The purpose of this study was to measure plaque accumulation on individual malpositioned teeth for comparison with contralateral nonmalpositioned teeth. Furthermore, the distribution of plaque in the anterior segments was measured and compared between aligned and nonaligned segments and the total mouth plaque score. Plaque scores and contact point indices were recorded from a total of 87 subjects of which 20 were drawn from dental and ancillary students and 67 from randomly chosen patients. For anterior teeth, in both groups significantly more plaque accumulated on malpositioned teeth compared with contralateral nonmalpositioned teeth. For the right-handed subjects (83), mean plaque scores for malpositioned teeth were greater than for nonmalpositioned teeth whether the malpositioned tooth was on the right or left of the anterior segment. This difference was significant in the patient group. The contact point index of the anterior segments correlated only with plaque accumulation in those subjects with a plaque index of less than 1. Upper and lower anterior segment plaque scores correlated with total mouth scores in both groups. However, the upper anterior segment scores had significantly less plaque than the total mouth score irrespective of the presence or absence of tooth malalignment, whereas the lower anterior segment always had significantly higher plaque scores than the total mouth score, irrespective of the presence or absence of malalignment. Finally, lower segments, whether aligned or malaligned, had significantly more plaque than upper anterior segments which were aligned or malaligned.

Adolescent↗
PubMed1981

Comparison of the bisbiguanide antiseptics alexidine and chlorhexidine. I. Effect on plaque accumulation and salivary bacteria.

A blind crossover trial was carried out to compare the effects of a 0.2% chlorhexidine gluconate mouthrinse and a 0.035% alexidine mouthrinse on plaque accumulation and salivary bacteria in a group of volunteers. The subjects refrained from all forms of oral hygiene during two 10-day periods and rinsed twice a day with the mouthwash randomly allocated to the respective period. Prerinse, day 4 and day 10 total salivary aerobic and anaerobic bacterial counts were determined during each period. Plaque scores were recorded at the end of each 10-day period. Significantly more plaque accumulated in subjects rinsing with alexidine when compared with chlorhexidine. Significant and comparable reductions in salivary bacterial counts were observed with both chlorhexidine and alexidine on day 4 and day 10 when compared with pre-rinse counts. Although at the concentrations used alexidine was less effective than chlorhexidine, it may be of value as a short-term adjunct to oral hygiene.

Adult↗
PubMed1981

Comparison of the bisbiguanide antiseptics alexidine and chlorhexidine. II. Clinical and in vitro staining properties.

A blind cross-over trial was carried out to compare the tooth and tongue staining associated with the use of a 0.035% alexidine and a 0.2% chlorhexidine mouthrinse. Twenty-two volunteers were divided into two groups termed "tea drinkers" and "non-tea drinkers". All volunteers were requested to refrain from oral hygiene measures throughout two 10-day periods when they rinsed twice a day with the preparation randomly allocated for the respective period. During both periods the members of the groups excluded coffee, red wine and port from their diet. The tea drinking group consumed seven cups of tea per day. Tooth and tongue staining was recorded for extent and severity at the end of each period. The amount of stain accumulating in the two groups was similar following the use of chlorhexidine and alexidine. However, for both chlorhexidine and alexidine the extent and severity of tooth and tongue staining were significantly increased in the tea drinking group. An in vitro study of tea staining of perspex blocks exposed twice a day to 0.035% solutions of alexidine or chlorhexidine throughout a 5-day period demonstrated significantly more staining with alexidine when measured spectrophotometrically. Visually however, the differences in the specimens were minimal. Saliva treatment of the perspex did not significantly alter the staining by alexidine or chlorhexidine. The results provide further evidence for a dietary aetiology to the staining associated with cationic antiseptics. However, alexidine at the concentration used offered no advantage in reducing the side effect of staining when compared with chlorhexidine.

Biguanides↗
PubMed1981

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↗
PubMed1981

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↗