Biomedical subjects

M Addy

Publications and source records attributed to M Addy.

At least 73 records · Page 4Linked to original sources

PubMed1992

Clinical aspects of dentine hypersensitivity.

Dentine hypersensitivity is a common painful condition about which relatively little is known. A review of the literature reveals that most research has been concerned with the clinical assessment of therapeutic agents. However, even here there is little information concerning the actual mode of action of such agents. Many clinical aspects of the condition also appear anecdotal at best and there is always a need to consider a differential diagnosis to exclude other causes of dentinal pain. Detailed prevalence figures are not available for dentine hypersensitivity as it affects different groups, although age and possibly gender differences are apparent. Additionally, the condition shows predilections for certain oral sites which may be of aetiological relevance. Consistent with the hydrodynamic theory hypersensitivity lesions reveal large numbers of widened dentinal tubules at the surface and patent to the pulp. The use of dentine replica techniques could prove useful in objectively studying the condition and monitoring treatments. It is apparent that in clinical management little attention has been paid to factors which expose dentine and open tubules. Without consideration of aetiological factors the management of Dentine Hypersensitivity may be compromised.

Dentin Sensitivity↗

PubMed1992

Ten years of kala-azar in west Bengal, Part I. Did post-kala-azar dermal leishmaniasis initiate the outbreak in 24-Parganas?

Following resurgence in Bihar of epidemic kala-azar, outbreaks of the disease were identified simultaneously in two separate foci about 500 km apart in West Bengal in 1980. While the outbreak in one of these foci, in northern West Bengal, was the result of a direct extension of the Bihar epidemic, the source of parasite in the other (in the village of Bandipur in the south of West Bengal) remained unknown until a case of nodulo-ulcerative post-kala-azar dermal leishmaniasis (PKDL) was located in the village. The continued presence of this case in the village from a time long before the outbreak aroused strong suspicion about its causal role. Laboratory-bred female Phlebotomus argentipes sandflies were allowed to feed on four cases of PKDL, including the case from Bandipur, to determine the transmission potential of these cases. Of a total of 400 flies in the experiment, 104 (26%) fed on the cases, and of these flies 44 died (31 within 48 hours of feeding). Of the surviving 60 flies, 32 developed promastigotes in the mid-gut. In view of the presence of the case of PKDL in the village prior to the outbreak and the availability of a susceptible human population and vectors, it is possible that the patient with PKDL was a source of Leishmania donovani parasites for the local focus. Furthermore, PKDL may act as a reservoir of parasites during inter-epidemic periods.

Animals↗

PubMed1991

Dentine hypersensitivity--effects of some proprietary mouthwashes on the dentine smear layer: a SEM study.

Exposed dentine may be sensitive to stimuli depending on the patency of the dentinal tubules. Most abrasive elements tend to produce a smear layer which obturates the dentinal tubules. This layer is easily removed by a number of erosive agents, particularly dietary acids. Mouthwashes are increasingly used and largely investigated for possible benefits to dental health. Rarely do studies assess potential detrimental activity. The aim of the present study was to examine effects of mouthwashes on dentine. Smear layers artificially produced on dentine sections were exposed, for time periods ranging from 3 to 300 min, to mouthrinses alone, or with subsequent brushing for 2 min using water or a fluoride toothpaste. Assessments were made by scanning electron microscopy. Of the nine rinses tested, six produced no consistently observable changes compared to water treated controls at any time period with or without brushing. A hexetidine rinse and a fluoride/antiseptic rinse both exposed tubules after exposure times of 2 h and longer, an effect enhanced by post-treatment brushing. A phenolic antiseptic rinse consistently removed the smear layer from specimens, an effect enhanced by brushing such that after 10 min exposure and 2 min brushing many tubules were open at the surface. The results indicate that the use of some mouthrinses could predispose to excessive tooth substance loss and dentine hypersensitivity, particularly if used prior to toothbrushing. There is a need to determine whether the intermittent use of some mouthrinses produces cumulative effects on dentine.

Benzoates↗

PubMed1991

The effect of orthodontic treatment on plaque and gingivitis.

The aim of the present investigation was to evaluate the relationship between the receipt of orthodontic treatment and subsequent periodontal health. Data from 417 children who were classified at baseline as having significant occlusal variations and who were present at the follow-up examination 3 years later were selected from an original cohort of 1015. One hundred fourteen of these children received orthodontic treatment over this time period and provided two groups of children for comparison in this study. Plaque indices, bleeding indices, and degree of dental irregularity were recorded for each incisor and canine tooth. There were significant reductions in the plaque and gingivitis scores on all tooth surfaces between the baseline and 3-year examination in the two groups of children. The children who had received orthodontic treatment had the greater reduction, but this appeared to be more related to behavioral factors than to improved tooth alignment.

Adolescent↗

PubMed1991

The use of an oxidising mouthwash to reduce staining associated with chlorhexidine. Studies in vitro and in vivo.

Discolouration of the teeth, tongue and dental restorative materials associated with the use of cationic antiseptics is still the limiting factor in long-term usage of antiplaque agents such as chlorhexidine. Oxidising agents have been used successfully to remove dental stain in animals, but products and regimens have not been evaluated in humans. These pilot studies in vitro and in vivo assessed a long-established oxidising mouthwash, based on peroxyborate, for stain removal from teeth and acrylic. The laboratory studies measured chlorhexidine tea stain removal from tooth and acrylic specimens. The oxidising agent markedly reduced staining on specimens. In a short-term clinical experiment, dental staining was forced over a 2 1/2-day period by reciprocal chlorhexidine and tea rinsing. 5 rinses with the oxidising mouthwash during the next 1 1/2 days dramatically reduced staining compared with water after rinses. Additionally, a single rinse with peroxyborate following the 5 water after rinses, again considerably reduced the residual staining. Effects on tongue staining were less impressive. Both experimental models produced findings consistent with those from the animal model. The results suggest proprietary oxidising mouthwashes could have a place in the control of dental stain associated with the use of chlorhexidine. Further studies to evaluate such products in a more conventional chlorhexidine regimen are indicated.

Adult↗

PubMed1991

The effect of some chlorhexidine-containing mouthrinses on salivary bacterial counts.

A number of chlorhexidine mouthwashes are available commercially which differ in formulation and regimen of use. As a comparative measure of antimicrobial persistence, this study evaluated the effect of 4 chlorhexidine mouthwash formulations on salivary bacterial counts after a single rinse. The study was a randomised single-examiner blind 5-way crossover investigation employing a panel of 10 young healthy human volunteers. The 0.12% and 0.2% commercial formulations when rinsed according to the respective manufacturers instructions produced similar large and prolonged reductions in salivary bacterial counts during the 7-h period. A 0.1% formulation also commercially available produced minimal effects on salivary bacterial counts and was little different to the saline rinse. A reformulated 0.1% rinse, not commercially available at the time of the study, produced significant salivary bacterial count reductions over the 7-h period albeit to a lesser degree of magnitude than to the 0.2% and 0.12% rinses. The results were consistent with comparative plaque inhibitory studies of the formulations and suggest that the method is a quick and simple way of screening products for antimicrobial and antiplaque potential.

Adult↗

PubMed1991

Triclosan and sodium lauryl sulphate mouthwashes (I). Effects on salivary bacterial counts.

A number of commonly used toothpaste ingredients, such as detergents, possess not inconsiderable antimicrobial activity. Additionally, specific ingredients including triclosan are now added to toothpastes to enhance such activity and to improve plaque inhibition. To date, there have been few studies of the antimicrobial properties in vivo of individual toothpaste ingredients. Most investigations have evaluated the whole toothpaste product. Persistence of antimicrobial action in vivo has been shown to relate to potential plaque inhibitory action. The aim of this study was to compare the magnitude and duration of salivary bacterial count reductions produced by a single rinse of 0.2% triclosan, 1% sodium lauryl sulphate (SLS) and 0.2% chlorhexidine mouthwashes. 16 volunteers took part in a single-blind latin-square randomised crossover designed study with balanced residual effects. Before and for time periods up to 420 min following rinsing with the allocated mouthwashes, saliva samples were obtained and processed for total anaerobic counts. With the exception of the saline control rinse, the 3 test solutions produced considerable reductions in bacterial counts which remained significant to 3 h for triclosan and 7 h for SLS and chlorhexidine. However, at most time periods after baseline, the effects of chlorhexidine were significantly greater than triclosan and SLS. Overall, SLS had significantly greater effects than triclosan. Incremental values from 30 min post rinsing were always positive for SLS and triclosan, indicating bacterial recovery, whereas these values were negative for chlorhexidine. The results indicate that triclosan and SLS provide some persistence of antimicrobial activity in the oral cavity when used at relatively high dose compared to a toothpaste vehicle.

Adult↗

PubMed1991

Triclosan and sodium lauryl sulphate mouthrinses. (II). Effects of 4-day plaque regrowth.

Toothpastes have been shown to exert some plaque inhibitory effects probably due to the action of detergents such as sodium lauryl sulphate (SLS). Recently the antimicrobial, triclosan, has been added to experimental and commercial toothpaste products to enhance activity against plaque. There is, however, little information as to the plaque inhibitory effects alone of ingredients such as SLS and triclosan. This investigation compared the effects on 4-day plaque regrowth of a 1% SLS, 0.2% triclosan and 0.2% chlorhexidine rinse with a 0.9% saline rinse. The study was single blind, latin square, four-period crossover design, balanced for residual effects and employing 16 healthy dentate volunteers. During each period, normal oral hygiene ceased and plaque regrowth from a zero baseline was measured by score and area after 2 x daily rinses with 10 ml volumes of each rinse. Washout was a minimum of 60 h. Plaque scores and areas were significantly lower with chlorhexidine than the other preparations and significantly higher with saline. There were no significant differences between SLS and triclosan. The results were essentially consistent with the similar substantivity of SLS and triclosan demonstrated from the salivary bacterial count investigation. Taste acceptability may, however, explain the small reverse trends noted between the two studies. It is concluded that both SLS and triclosan would individually confer plaque inhibitory properties to toothpaste formulations. However, when combined in a single formulation, their effects may not be additive.

Adult↗

PubMed1991

The effects of a cetylpyridinium chloride prebrushing rinse as an adjunct to oral hygiene and gingival health.

A NUMBER OF MOUTHWASH PRODUCTS containing cetylpyridinium chloride (CPC) are available. Data for individual products are limited, although overall the antiseptic has been shown to reduce plaque. Results for gingivitis reductions by CPC have been equivocal. This study was an active/placebo parallel group design to evaluate the use of a CPC mouthrinse as an adjunct to oral hygiene when used before toothbrushing. Plaque and gingivitis scores were recorded at baseline and after 6 weeks, following twice daily use of the active or placebo prebrushing rinses. Plaque and gingivitis were significantly reduced at 6 weeks in both groups with no significant treatment differences between the active and placebo formulations. Whether the order of rinsing to toothbrushing influenced these findings cannot be determined. However, the results further question the adjunctive benefits of CPC rinses to gingival health.

Cetylpyridinium↗

PubMed1991

Leishmanial blepharo-conjunctivitis.

We describe a case of blepharo-conjunctivitis due to Leishmania donovani in association with nodules of post kala azar dermal leishmaniasis (PKDL) on the chin. The diagnosis was confirmed by isolation of the parasite in culture. Direct implantation of the parasite by contaminated fingers from the chin nodules to the eye is suggested as the mode of spread. The role of cell-mediated immunity, (CMI) in restricting the skin lesions on the chin for 37 years at the same site, was suspected. This is only the second report of ocular involvement in L. donovani infection from India.

Agglutination Tests↗

PubMed1991

Staining and antimicrobial properties in vitro of some chlorhexidine formulations.

Dietary staining studies have proved useful determinants of chlorhixidine activity in mouthrinse products, and results correlate with plaque inhibitory effects. This investigation compared the staining and antimicrobial action in vitro of two known and similarly effective, commercially available chlorhexidine mouthrinses with a reformulated 0.1% chlordexidine preparation. After adjustment for original concentration the 0.2%, 0.12% and reformulated 0.1% products had essentially similar, minimum inhibitory-dilution values against standard test organisms. The 0.1% preparation was more effective against Capnocytophaga ochracea, suggesting additional antimicrobial activity derived from an ingredient other than chlorhexidine. The staining in vitro of tooth and acrylic specimens was equivalent with the 0.2% and 0.12% products. By comparison with equivalent concentrations of the diluted 0.2% preparation, the 0.1% formulation produced less staining, particularly when diluted. The data suggest that the 0.1% formulation, when used in diluted form as recommended by the manufacturer, may have slightly reduced plaque-inhibitory effects by comparison to the 0.2% or 0.12% products. However, the results raise the question whether chlorhexidine solutions could be formulated to reduce side effects, in particular, tooth staining at the expense of some loss of antiplaque activity.

Acrylic Resins↗

PubMed1991

A longitudinal study of the condition of first permanent molars in a group of adolescents with special reference to elective orthodontic tooth extraction.

The aim of this study was to investigate changes in the condition of first permanent molars over the teenage years, with special reference to adolescents who lost premolar teeth for orthodontic purposes. A total of 453 South Wales schoolchildren (219 males and 234 females) were examined at the ages of 11-12 and 19-20 years. At 11-12 years, 89.6 per cent of the cohort had all four first permanent molars, while 3.3 per cent had already lost these teeth. Of those first permanent molars present, 61.7 per cent had some caries experience. At age 19-20, 80.6 per cent of subjects retained four first permanent molars while 4.4 per cent had none. Of the first permanent molars present, 80.6 per cent had been affected by caries. In 60 per cent of the 186 subjects (75 males and 111 females) who had lost premolar teeth in the course of orthodontic treatment, a sound premolar was extracted in preference to a first permanent molar which already had evidence of dental disease. At age 19-20 years, the majority of the first permanent molars were restored and otherwise sound, though a small number which had been restored at age 11-12 years had been lost due to caries.

Adolescent↗

PubMed1990

Factors influencing the initiation of carious lesions in specific tooth surfaces over a 4-year period in children between the ages of 11-12 years and 15-16 years.

An analysis of factors influencing the initiation of carious lesions on specific tooth surfaces over a 4-year period in children between the ages of 11-12 years and 15-16 years is presented. Approximately 1000 children, resident in the County of South Glamorgan, Wales, were assessed for caries status and oral cleanliness in 1980 when aged 11-12 years and again in 1984 when aged 15-16 years. On both occasions, the children completed detailed questionnaires on dental health-related topics. Surfaces which were sound when the children were 11-12 years were identified and subsequently awarded a score of zero if they remained sound at 15-16 years or a score of one if they had developed carious lesions or had been filled. For each child, a mean mouth caries initiation score was computed for specific groups of surfaces, namely pit and fissure surfaces in posterior teeth, approximal surfaces in posterior teeth, buccal and lingual smooth surfaces of all teeth and approximal surfaces of anterior teeth. One-way analysis of variance and multiple regression techniques revealed that a number of factors had a significant influence on the initiation of caries. The factors and their level of significance varied between the surfaces. However, relatively little (less than 6 per cent) of the total variance in caries initiation score could be explained by the identified factors. Overall, more lesions developed in pit and fissure surfaces in posterior teeth than in the other surfaces included in the analyses.

Adolescent↗

PubMed1990

Factors influencing the caries experience of a group of children at the ages of 11-12 and 15-16 years: results from an ongoing epidemiological survey.

An analysis of factors influencing the caries experience of adolescents in South Wales is presented. Approximately 1000 children were assessed for caries status and oral cleanliness in 1980 when aged 11-12 years and again in 1984 when aged 15-16 years. In addition, on both occasions, the children completed detailed questionnaires on dental health-related topics. When aged 11-12 years, the observed mean DMFT, DMFS and DFS scores of the children were 4.0, 6.7 and 5.5 respectively. The corresponding scores at age 15-16 years were 6.5, 11.8 and 10.2. A preliminary analysis using conventional multiple regression techniques revealed that a number of factors had a significant influence on the caries experience of the children. The significance of the factors depended on the sex of the population subgroup, the age of the children and the particular caries index studied. However, at both ages the factors of most significance were the number of erupted teeth, total mean plaque score and the reported amount of money spent on sweets per week. A further evaluation using analysis of covariance with the number of erupted teeth and surfaces as the covariates confirmed the significant influence of the total mean plaque score and amount of money spent on sweets. In addition, both analyses indicated that toothbrushing frequency and social class had a significant influence on the caries experience of boys.

Analysis of Variance↗

PubMed1990

The effect of triclosan, stannous fluoride and chlorhexidine products on: (I) Plaque regrowth over a 4-day period.

A number of substances have been incorporated into toothpastes or gels to inhibit plaque regrowth. The aim of this study was to evaluate triclosan and stannous fluoride products for plaque inhibitory properties by comparison with a chlorhexidine or saline rinse and a control product which was a conventional commercially available toothpaste. In a blind 8 cell cross-over study, 15 volunteers rinsed 2 x a day for 4 days with slurries of the products or the saline and chlorhexidine solutions. No other form of oral hygiene was performed and plaque regrowth from a zero baseline was recorded by plaque score and plaque area. Plaque regrowth was significantly less with the chlorhexidine rinse and significantly greater with the saline rinse compared to the toothpaste and gel products. No significant differences were found between the test and control products. The results again demonstrate that commercially available toothpastes have plaque inhibitory effects which so far appear difficult to improve upon by the addition of specific ingredients, in this case stannous fluoride or triclosan. Commercially available products of known activity would appear useful benchmarks for comparison of experimental formulations.

Adult↗

PubMed1990

The effect of triclosan, stannous fluoride and chlorhexidine products on: (II) Salivary bacterial counts.

A previous study demonstrated that triclosan and stannous fluoride containing oral hygiene products reduced plaque regrowth compared to saline but were not more effective than a conventional commercial fluoride/anionic detergent toothpaste. To further understand these results, this study measured the persistance of antimicrobial activity of the same products by recording the duration of salivary bacterial count reductions following a single exposure to each product. Comparison was also made with a chlorhexidine rinse as the positive control. From a panel of 16 volunteers, in an 8-cell randomised cross-over designed study, salivary bacterial counts were recorded at baseline and to 420 min. All test and control products were significantly more effective than saline and significantly less effective than chlorhexidine at suppressing bacterial counts. Unlike chlorhexidine, evidence of bacterial recovery was apparent after the 30-min sampling time. There were essentially no significant differences between the test and control products, although the stannous fluoride toothpaste performed marginally better than other products. The findings are consistent with the plaque regrowth results previously obtained and again demonstrate to date that it is difficult to surpass the antimicrobial and plaque inhibitory properties of conventional commercially available toothpastes by the addition of antimicrobial agents such as triclosan and metal salts.

Adult↗

PubMed1990

The effects of 0.5% chlorhexidine and 0.2% triclosan containing toothpastes on salivary bacterial counts.

A number of antimicrobial compounds could be incorporated into toothpastes to enhance plaque inhibitory effects. However, the number of possible formulations is immense and makes clinical testing in plaque and gingivitis studies difficult. In this study, the effects on salivary bacterial counts of a number of chlorhexidine and triclosan toothpastes was evaluated as a predictor of persistence of antimicrobial action in the mouth. The study was a supervised, randomised 15-way crossover study employing 10 healthy human volunteers. All toothpastes were brushed for 1 min and comparison made with a 0.2% chlorhexidine rinse. The latter produced a large drop in salivary bacterial counts to the end of the 7-h study period. The toothpastes decreased salivary bacterial counts and all but two had notably more effect than a water brushing. No toothpaste showed a significant persistence of antimicrobial effect beyond 5 h. In the light of available plaque inhibition data for the toothpastes, persistence of antimicrobial activity beyond 5 h will be necessary for a clinical effect on plaque and gingival health. The method appears to be a simple and rapid screening technique for products formulated to enhance plaque inhibition mediated through an antimicrobial action.

Adult↗

PubMed1990

Comparative effects of toothpaste brushing and toothpaste rinsing on salivary bacterial counts.

The persistence of antimicrobial action of compounds and formulations in the mouth can be demonstrated by recording the magnitude and duration of the reduction of salivary bacterial counts following a single application. Such measures of substantivity appear to correlate with the plaque inhibitory properties of antimicrobial agents. For toothpastes, studies on the short-term inhibition of plaque formation use a number of delivery methods to measure the direct effect of the preparation divorced from toothbrushing. Such methods include paste slurries, paste in trays or cap splints. This study determined whether toothbrushing with a toothpaste produced the same effects on salivary bacterial counts compared to rinsing with a slurry. A group of 24 volunteers brushed or rinsed with a slurry of a commercial toothpaste. Each regimen was repeated twice on 4 separate days by all volunteers and salivary bacterial counts recorded at baseline and time periods to 7 hours. There were no significant differences between brushing or slurry rinsing on salivary bacterial counts and each method produced reproducible effects. This supports the use of the slurry method where the direct plaque inhibitory action of an antimicrobial toothpaste is to be assessed; and indicates that both methods equally make available and activate the relevant ingredients in formulations.

Adult↗