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Biomedical subjects

P Warren

Publications and source records attributed to P Warren.

At least 37 records · Page 2Linked to original sources
PubMed1999

An evaluation of video instruction for an electric toothbrush. Comparative single-brushing cross-over study.

Instructions on the use of electric toothbrushes are usually derived from the written and/or diagrammatic leaflets provided with the device or perhaps less often instruction from a professional. Videos are now widely used for information transfer and the direction of physical activities. The aim of this study was to determine whether video instruction in the use of an electric toothbrush could promote efficient use of the device. The 2-min video demonstrated the use of an oscillating, rotating electric toothbrush used by a hygienist for 15 s in each buccal and lingual quadrant. A voice-over directed the observer to follow the hygienist's movements. The study was planned as a 2-phase, single-examiner blind, randomised, cross-over study accepting there would be confounding of the 2nd period by carry-over from the 1st. A group of 24 healthy volunteers participated who had average oral hygiene and never used an electric toothbrush. 12 subjects received the video first (VN) and 12 subjects the instructional leaflet with the device (NV). Single brushings were performed after suspending tooth cleaning for 48 h. Plaque was scored before and after brushing. A 2-week washout period was permitted before the crossover. In period 1, plaque removal with the video was overall significantly greater than with written instructions. The effects for posterior teeth were greater than anterior and comparison between groups for posterior minus anterior differences were highly significant in favour of the VN group. In period 2, the effect of period was dominant with both groups achieving greater plaque removal in period 2 than period 1. Plaque removal by group VN remained considerably greater than group NV Despite the confounding influences of carry-over in this particular design of study, the results support the idea that video instruction for electric toothbrushes could be a simple and efficient way of improving plaque removal by these devices. The methodology needs to be verified in a home-use type of investigation.

Adult↗
PubMed1999

Conversion of plaque-area measurements to plaque index scores. An assessment of variation and discriminatory power.

Plaque areas recorded graphically or photographically provide a permanent record of plaque accumulations on teeth at a moment in time. As such, these records could be re-evaluated and converted into other index scores. The purpose of this study was to determine the reproducibility of scoring a plaque index from previously recorded plaque areas and to compare such scores with the original scores of the same index. A randomised blind, crossover study comparing 5 treatments for plaque inhibition scored by plaque area and index was chosen. 2 examiners, the original scorer PRH and another, NC, 2x scored the plaque area tooth charts according to the criteria of the plaque index system used in the original study. Standard deviations of the differences showed intra-examiner repeatability to be high particularly for the original examiner. Inter-examiner reproducibility for the original index scores was considered good but less than for intra-examiner repeatability. Correlation coefficients were complimentary to the differences analysis, being very high within examiners and less high for between examiners and original and rescored index. Separation between distributions of plaque area measurements for consecutive values of the index were particular good for scores 2 versus 3 and 3 versus 4 and less good for 1 versus 2 and 4 versus 5. Reanalysis of the study for treatment differences using rescored data revealed a similar level of significance as using the original data. Rescored index had similar discriminatory power for the study as plaque area and original plaque index when both were derived from the same buccal tooth surfaces. However, discriminatory power was less by comparison with original plaque index derived from the buccal surfaces of all teeth. It is concluded that plaque area provides a permanent record of plaque distribution which can be converted into index data at a later date. Such data collection could make possible comparisons between studies using different indices.

Cross-Over Studies↗
PubMed1999

Comparison of video and written instructions for plaque removal by an oscillating/rotating/reciprocating electric toothbrush.

A previous crossover study showed that a watch-and-follow instructional video improved plaque removal by an electric toothbrush compared to the use of the instructional leaflet. This study employed a parallel design to assess the value of an instructional video for plaque removal by a new model oscillating/rotating/reciprocating electric toothbrush. 2 groups of 26 dentate subjects with average oral hygiene, who had never used an electric toothbrush, participated in this single blind, randomised parallel group designed study. On day 1 of the study, subjects received a professional prophylaxis to remove all plaque. Oral hygiene measures were then suspended and subjects returned on day 3 when a prebrushing plaque score was recorded by plaque index and area. Subjects withdrew and either read the manufacturers instructional leaflet (group L) or observed the instructional video (group V). Groups L and V then performed toothbrushing with toothpaste for 2 minutes and with group V brushing in time with the instructional video. Post-brushing plaque indices and areas were then recorded. Whole mouth, lingual, upper, lower, anterior and posterior but not buccal % reductions in plaque index and area were significantly greater in group V compared to group L. % plaque removal was also significantly greater by area at mid and distal sites but not mesial sites. Whole-mouth plaque reductions were 10% greater in group V but reached >15% at lingual surfaces. Within group differences in plaque removal at paired sites e.g., buccal/lingual, remained similar, suggesting that further improvement could be achieved by modifying the video to devote more time to the difficult-to-clean areas. In conclusion, in the early period of learning the use of an electric toothbrush, plaque removal can be improved by using an instructional video. Such watch-and-follow video routines could be extended to other areas of oral hygiene practices.

Adult↗
PubMed1999

A review of 1019 consecutive cases of polycystic ovary syndrome demonstrated by ultrasound.

Analysis of a cohort of 1019 consecutive subjects with ultrasonically demonstrable polycystic ovary (PCO) syndrome demonstrated a significant relationship between biochemical parameters and clinical symptoms such as menstrual frequency and severity of hirsutism. One hundred and forty-four subjects presented with involuntary infertility and only eight cases had unexplained infertility apart from PCO.

Anthropometry↗
PubMed1998

A practice-based randomised controlled trial of the efficacy of an electric and a manual toothbrush on gingival health in patients with fixed orthodontic appliances.

OBJECTIVES: The aim of the present study was to evaluate the efficacy of an electric toothbrush with a specially designed orthodontic brush head compared with a manual toothbrush in controlling plaque and gingivitis in patients with fixed orthodontic appliances over an 8-week period in a dental practice setting. METHODS: This was a randomised controlled, single blind, stratified, parallel group trial conducted in two specialist orthodontic dental practices by a specialist orthodontist. Group 1 comprised 41 subjects who used the electric toothbrush and Group 2 consisted of 43 subjects who brushed with a manual toothbrush around the orthodontic appliance for a timed 2 minutes twice daily for 8 weeks. Plaque around the fixed appliance attachments was measured using an orthodontic modification to the Silness and Loe plaque index, while gingival condition was scored using the gingival index and Eastman interdental bleeding index. RESULTS: There was baseline balance for all clinical variables (p > 0.05). Both groups had significantly less plaque after 8 weeks than at baseline (p < 0.001) but the group using the electric brush also had significantly less interdental gingival bleeding, as determined by the Eastman interdental bleeding index both at week 4 (p < 0.001) and week 8 (p = 0.004). The majority of subjects (n = 54, 64.3%) preferred the electric toothbrush. CONCLUSIONS: In conclusion, the results from this study would suggest that use of an electric toothbrush with an orthodontic brush head may be of benefit in promoting gingival health in fixed orthodontic appliance patients; however, the long-term effects (over at least 6 months) need to be evaluated.

Adolescent↗
PubMed1998

Home use oral hygiene product trials; timing of the last brushing before scoring; an assessment of variation.

Home use studies to evaluate oral hygiene products often standardise the time lag between plaque scoring and the previous toothbrushing. Most protocols have favoured an evening before brushing regimen, but the rationale and even the validity of this approach has not been evaluated. In this study, a group of 30 adult subjects participated in a 4-period randomised single-blind crossover evaluation of within-subjects and between-subjects variation in plaque levels after two different brushing times. Thus, on 2 occasions, plaque was scored after an "evening before" brushing and on the other 2 occasions plaque was scored after a "morning before" brushing. As expected, mean plaque levels were lower after morning brushing, but only by 11%. There was little difference for lingual plaque (4%) but a greater difference for buccal plaque (18%). Comparisons for within-subjects variation, which ideally should be low, favoured morning brushing but differences were small and not significant. Comparisons for between subjects variation, which ideally should be high to permit discrimination between high and low plaque formers, also favoured morning brushing but were only significant for lingual plaque. Intraclass correlation coefficients of reliability revealed that overall repeatability was high for both morning and evening regimens; marginally favouring morning brushing. Analyses using all four scores per subject disregarding timing of brushing increased within subjects variation and decreased repeatability, particularly for buccal plaque. In conclusion, the data support the concept of standardising the time between plaque scoring and the previous tooth-brushing. There were no clear statistically significant grounds for preferring one brushing regimen to the other, however the data favoured the morning brushing.

Adult↗
PubMed1997

Donor work-up and transport of bone marrow--recommendations and requirements for a standardized practice throughout the world from the Donor Registries and Quality Assurance Working Groups of the World Marrow Donor Association (WMDA).

In October 1995 the World Marrow Donor Association (WMDA) was restructured in order to facilitate its primary function of establishing guidelines in relation to international bone marrow and blood stem cell transplants -- transplants in which the donor is in one country and the patient is in another country. Five new working groups were established -- Donor Registries, Ethics, Quality Assurance, Finances, and Stem Cells. This paper, prepared by members of the Donor Registries Working Group, in consultation with the Quality Assurance Working Group, provides recommendations for the 'donor work-up'. This term covers events that start when the definitive donor has been identified, includes the harvesting (collection) and transportation of the stem cell product and ends when the product reaches the transplant centre. The paper includes examples of the documentation intended to ensure compliance with the recommendations at all key points in the sequence.

Bone Marrow Transplantation↗
PubMed1997

Methods for microscopic characterization of oral biofilms: analysis of colonization, microstructure, and molecular transport phenomena.

Assessment of the role of biofilm microstructure in biofilm-specific activities requires non-destructive measurement techniques for parameterization of structural characteristics in parallel with relevant biochemical and physiological data. This paper briefly reviews some current methods for biofilm structural analysis, with emphasis on new developments in optical imaging and mathematical modeling methods. Fluorescence imaging studies of bacterial colonization events occurring on exposed model tooth surfaces indicated that bacterial adhesion to sessile organisms was of central importance to the early colonization process and that this occurred in a non-random manner. Structural studies of mature biofilms by confocal microscopy demonstrated the spatial distribution of individual species using fluorescent antibodies. Biofilms grown under different physiological conditions exhibited differences in structure, and methods were developed for parameterizing the spatial orientations of the bacteria. Diffusive processes within biofilm microstructures were studied using a random walk model in both 2-D and 3-D. Modeling of convective flow within biofilm microstructures was achieved by application of lattice Boltzmann methodology.

Bacteriological Techniques↗
PubMed1997

Pulmonary illness associated with exposure to Mycobacterium-avium complex in hot tub water. Hypersensitivity pneumonitis or infection?

BACKGROUND: Mycobacterium avium complex is common in water. When aerosolized, it is frequently inhaled but rarely causes illness in healthy people. Hypersensitivity pneumonitis to inhaled aerosols has been described; these aerosols are from several sources of water. The pneumonitis forms are collectively known as humidifier lung; the responsible agent in the water remains uncertain. PURPOSE: To report five cases of respiratory illness in healthy subjects using hot tubs contaminated with M avium complex. DESIGN: Descriptive case reports. SETTING: Consultations in two teaching hospitals. PATIENTS: Five healthy people developed respiratory illnesses characterized by bronchitis, fever, and "flu-like" symptoms after using a hot tub. Acute exacerbations of their illness developed within hours of heavy use of the hot tubs. INVESTIGATIONS: A chest radiograph and sputum culture in all, BAL in one, CT scan and lung biopsy in another were performed. Culture of the water of the two hot tubs also was done. RESULTS: Chest radiographs showed interstitial infiltrates or a miliary nodular pattern. Cultures of all sputum samples, the lung biopsy specimens, lung lavage and water samples were positive for M avium complex. The lung biopsy specimen revealed noncaseating granulomas. All patients recovered with no treatment for M avium complex. CONCLUSION: We conclude that the M avium complex in the water was responsible for the pulmonary illnesses. The symptoms and the results of investigations are more suggestive of a hypersensitivity pneumonitis than of an infection, but no serologic proof of an immunologic reaction to the M avium complex or water was obtained.

Adolescent↗
PubMed1997

The safety and efficacy of gingival massage with an electric interdental cleaning device.

The safety and efficacy of an interdental cleaning device (Braun Oral-B Interclean--ID2) used with a Flexi-Tip gingival massage attachment were evaluated in an investigator-blind comparison with manual floss. Over a 4-week period, 59 healthy volunteers were studied with respect to whole-mouth and interproximal plaque accumulation, gingival index and gingival bleeding. Eligible subjects were randomly assigned to one of the two experimental groups following a complete dental examination on Day 1. Subjects each underwent a dental prophylaxis before receiving flossing or massaging instructions. Plaque, gingivitis and gingival bleeding index scores were evaluated at Day 1 and Week 4. There was a significant reduction from baseline in all three parameters (whole-mouth and interproximal) in each of the groups, over the 4-week period. Reductions for whole-mouth and interproximal plaque scores were 20.3% and 17.0%, respectively in the ID2 group, compared with 16.2% and 13.8%, respectively in the manual floss group. Reductions for gingivitis were 13.0% and 14.1% in the ID2 group, compared with 14.0% and 16.2% in the manual floss group, and for gingival bleeding 52.2% and 53.6% in the ID2 group, compared with 51.7% and 55.6% in the manual floss group, respectively. Differences between treatment groups for each study parameter were not statistically significant. There was no significant soft tissue pathology noted in either study group. The results demonstrated that the manual floss and the interdental cleaning device, when used with the gingival massage attachment, were equally effective.

Adolescent↗
PubMed1995

House dust mite allergen levels in two cities in Canada: effects of season, humidity, city and home characteristics.

The homes of 120 patients with asthma, 57 in Vancouver and 63 in Winnipeg, were studied. The characteristics of the homes were assessed by a questionnaire. Dust samples were collected and the indoor relative humidity was measured four times during the year covering all four seasons in both cities. Mite allergen levels were determined using monoclonal antibodies against Der p I and Der f I by the ELISA method. The mean levels of both mite allergens in mattress and floor samples in the homes in Vancouver and in Winnipeg were relatively low for all seasons. Mite allergen levels were found to be associated with city, season and individual home differences. They were significantly higher in Vancouver than in Winnipeg. Der p I and Der f I in mattress samples in both cities and Der f I in floor samples in Vancouver, varied by season. The indoor relative humidity level in the homes in Vancouver were also significantly higher than those in Winnipeg. There was, however, no significant association between the levels of indoor relative humidity and the levels of mite allergens after adjusting for variations in city, season and individual home. Although individual home differences were highly associated with mite allergen levels, only a few home characteristics were found to be related to mite allergen levels such as the type and the age of the home, the type of heating, the use of feather pillows and the number of occupants in the homes. Whether low levels of mite allergens are partially responsible for the relatively low prevalence of childhood asthma in Canada remains to be investigated.

Allergens↗
PubMed1995

The comparative tea staining potential of phenolic, chlorhexidine and anti-adhesive mouthrinses.

Staining of teeth and mucous membranes is a well-known side-effect with chlorhexidine mouthrinses in which dietary chromogens play an important rôle. The purpose of this study was to determine whether a co-polymer anti-adhesive agent would prevent staining by a low concentration chlorhexidine solution. Additionally, the possibility that an essential oil/phenolic rinse product may cause staining was investigated. The rinses studied were the anti-adhesive alone and combined with 0.02% chlorhexidine and the essential oil/phenolic rinse. These were positioned against a positive control rise, 0.2% chlorhexidine, and a negative control rinse, water. The study was a single blind 5-treatment, randomised Latin square cross-over design, incorporating balance for carry-over effects. 15 volunteers participated and on Day 1 of each study period were rendered stain free by scaling and polishing of the teeth. Oral hygiene was suspended and 8 x per day subjects rinsed under supervision, firstly with the allocated formulation and then with 10 ml of warm black tea. On Day 4, tooth and tongue staining was scored by area and intensity (colour). A washout period of at least 3 1/2 days was permitted between treatment periods when oral hygiene was resumed. Before the study and during washouts, volunteers practised tongue brushing. Tooth and tongue staining was significantly increased with 0.2% chlorhexidine compared to the essential oil/phenolic rinse which in turn was significantly increased compared to the other 3 rinses. The antiadhesive/chlorhexidine rinse produced no more staining than the anti-adhesive or water rise. However, the parallel plaque regrowth study suggests this inhibition of staining resulted from the vitiation of the chlorhexidine activity by the antiadhesive. The methodology would appear a simple and quick way of assessing the propensity of mouthrinses to cause extrinsic staining.

Anti-Infective Agents, Local↗