Biomedical subjects

N Claydon

Publications and source records attributed to N Claydon.

15 recordsLinked to original sources

PubMed2004

Clinical development and evolution in plaque removal performance of a battery powered toothbrush.

BACKGROUND AND AIM: There is growing evidence that the new generation of electric toothbrushes are more effective than manual toothbrushes. The primary aim of these studies was to compare, as an indication of the stage of development, the plaque removal properties of a prototype battery powered toothbrush with an established product. A secondary aim was to utilise the data to appraise plaque accumulation together with the patterns of removal. METHOD: The three studies presented used the same, single-examiner, randomised, single-blind cross-over design involving up to 24 healthy volunteers. The prototype brushes, E6500 versions s1, s2 and s3 and E8000 with head speeds of 6500 and 8000 oscillations/min were compared with a similar design marketed product (MP) with a head speed of 8800 oscillations/min. All brushes had circular brush heads with oscillating rotating actions. Subjects accumulated plaque over a 4-day period during which no oral hygiene measures were performed. On day 4, the plaque accumulation was scored by index. Subjects then used the allocated toothbrush for 2 min. This was followed by a re-scoring of the remaining plaque. RESULTS: Studies 1 and 2 showed significantly less plaque removed by prototype E6500 (s1) and prototype E6500 (s2), respectively, than by MP. In study 3, prototype E8000 removed similar quantities of plaque to MP (approximately 65%). In contrast prototype E6500 (s3) only removed 60% of accrued plaque. Differences, however, did not reach statistical significance. CONCLUSIONS: The study methodology was appropriate to distinguish between the study toothbrushes and was furthermore able to establish a level of comparability for one of the prototype modifications with a similar MP.

Adult↗

PubMed2004

A methodology using subjective and objective measures to compare plaque inhibition by toothpastes.

OBJECTIVES: Plaque scoring usually employs subjective indices. The aim was to compare plaque inhibition of three toothpastes using two objective and one subjective measures of plaque. MATERIAL AND METHODS: Formulations were: (1) an experimental anti-plaque paste (test); (2) an experimental paste (minus active or negative control); and (3) a proprietary anti-plaque toothpaste product (positive control). The study was a blind, randomised crossover design using a 4-day, no tooth brushing, plaque regrowth model and involving 22 healthy subjects. After baseline plaque removal, subjects rinsed twice a day with slurries of the allocated paste. On day 5, plaque was scored by index, wet weight and optical density of extracted disclosing solution from the plaque (stain intensity). RESULTS: All data showed the same pattern. There were highly significant subject and treatment effects but not period effects. The positive control was highly significantly more effective in plaque control than the test and minus active experimental formulations, which in turn were not significantly different from each other. There were strong and significant correlations between pairs of scoring methods particularly wet weight and stain intensity. CONCLUSION: The use of objective methods of plaque alongside conventional subjective indices provided convincing evidence for increased discriminatory power in a study comparing plaque inhibition by toothpastes.

Adult↗

PubMed2002

Comparative professional plaque removal study using 8 branded toothbrushes.

BACKGROUND AND AIM: Considerable interest has been shown in the plaque removal properties of modern toothbrush designs. The primary aim of the study was to compare the plaque removal properties of 8 relatively recent designs of manual toothbrush using a professional tooth brusher and within a commonly used time frame. A secondary aim was established to utilise the data to observationally appraise plaque accumulation together with the patterns of removal as a consequence of using the timed professional tooth brusher. METHOD: The method was an 8-period, single-examiner, randomized, blind cross-over study involving 24 healthy volunteers, balanced for residual effects. Subjects accumulated plaque over a 4 day no oral hygiene period. On day 4, the accumulated plaque was scored by plaque index at the mesial, mid and distal sites of each of the buccal and lingual surfaces of the assessed teeth. Subjects were then removed from the assessment area where they received a professional brushing timed to last 48 s. Brushing was completed according to pre-study training without toothpaste and was followed by a re-scoring of the remaining plaque. A washout period of 3 days was then allowed prior to the next period during which normal oral hygiene was resumed. RESULTS: Similar quantities of plaque accumulated in each arch, although the difference between the buccal and lingual surfaces was of the order of 30%. The professional toothbrusher removed approximately 40% of the accumulated plaque in the 48 s allocated. The buccal surfaces were most effectively cleaned (approximately 45%) compared with the lingual (approximately 25%), with the plaque removal in the mesial and mid sections approaching 40% and 60% respectively. The difference in performance between the test brushes corresponded to 5% of the residual plaque values with none being significantly more efficient overall. Pair wise site comparisons did produce differences of the order of 10% (p=0.004) at the mesio-buccal, and 8% (p=0.030) at the mid-buccal sites respectively in favour of 2 brushes compared to one other brush. CONCLUSIONS: These data derived from a standardized brushing method support the contention of many researchers that there is no one superior design of manual toothbrush. The minor and few site differences in favour of some brushes are unlikely to be of clinical significance to gingival health. This leaves uncontested the conclusion that the user is by far the most significant variable. Perhaps methods such as used in the present study could be more gainly employed to set a minimum standard of toothbrush efficacy.

Analysis of Variance↗

PubMed2002

A comparison of the plaque-inhibitory properties of stannous fluoride and low-concentration chlorhexidine mouthrinses.

BACKGROUND: Plaque inhibition by chlorhexidine (CHX) rinses is dose related with a relatively flat dose-response curve above 5-6 mg twice daily. Low dose regimens could therefore reduce local side effects but maintain reasonable efficacy. AIMS: To compare the plaque inhibitory properties of two low-dose CHX rinse products with more conventional levels delivered from proprietary rinses. A secondary outcome was a comparison with a stannous fluoride/amine fluoride (SFAF) rinse product. METHODS: The study was a five-treatments, negative controlled, randomised, single blind crossover design balanced for residual effects, involving 20 healthy subjects in a 24-h plaque re-growth model. On day 1 of each study period, subjects were rendered plaque free, suspended tooth cleaning and followed the appropriate rinse regimen. On day 2, subjects were scored for plaque by index and area. The rinse codes and rinsing regimens were: (A) 15 mg CHX 2 x daily for 30 s (0.1% CHX), (B) 9 mg CHX 2 x daily for 60 s (0.06% CHX), (C) 10 ml SFAF rinse 1 x daily for 30 s, (D) 15 ml placebo 2 x daily for 60 s, and (E) 6 mg CHX 2 x daily for 30 s (0.06% CHX). RESULTS: Average mouth plaque indices and areas were highly significantly different between rinsing regimens. All test rinses were significantly more effective than the placebo rinse. There was a mean dose-response pattern for the CHX rinses, but there were no statistically significant differences between any of the test rinses. CONCLUSIONS: Lower doses of chlorhexidine in rinses can be used to exert plaque inhibition comparable with products used at higher doses and equivalent to benchmark products such as the SFAF rinse. However, the availability of chlorhexidine from formulations has to be considered as in part explaining the results.

Adult↗

PubMed2001

Studies on the effect of polyvinyl pyrrolidone on the activity of chlorhexidine mouthrinses: plaque and stain.

BACKGROUND, AIMS: Polyvinyl pyrrolidone (PVP) was shown in vitro to reduce chlorhexidine induced, dietary staining without affecting the uptake of the antiseptic to the test substrate. The aim of these studies in vivo was to determine whether PVP affected plaque and dietary staining by a low concentration chlorhexidine rinse. METHODS: The plaque and stain studies used a double blind, randomised 6, treatment crossover design involving healthy subjects with a high standard of oral hygiene and gingival health. The rinse formulations under test were: (A) aqueous alcohol (placebo control), (B) 0.03% chlorhexidine, (C) 0.06% chlorhexidine, (D) 0.06% chlorhexidine+1.2% PVP, (E) 0.06% chlorhexidine+5% PVP, (F) 0.06% chlorhexidine+10% PVP. In the plaque study, on day 1 of each period, subjects were rendered plaque free and then rinsed with 15 ml of the test rinse for 60 s. No further tooth cleaning was performed and subjects returned 24 h later for plaque scoring by area. In the stain study, on day 1 of each period, the tongue and teeth of each subject were rendered stain free. Subjects then rinsed under supervision for 60 s with 15 ml of the allocated rinse 8 x a day between 09:00 h and 17:00 h for 3 days. Immediately after each rinse with the test formulation, subjects rinsed for 120 s with 15 ml of warm black tea. Subjects were requested to also drink at least 5 cups of tea or coffee per day. On day 4, stain was scored by area and intensity from designated teeth and dorsum of the tongue. Washout periods were at least 7 days in both studies. RESULTS: Plaque areas were greatest with placebo and least with 0.06% chlorhexidine. Plaque scores increased with increasing concentrations of PVP in the 0.06% chlorhexidine rinse and were significantly higher than 0.06% chlorhexidine without PVP rinse. Tooth stain areas were comparable for placebo, 0.03% and 0.06% chlorhexidine rinses, but significantly reduced with the PVP/chlorhexidine rinses compared to the 0.06% chlorhexidine rinse. Tooth stain intensity was significantly increased with 0.06% chlorhexidine rinses compared to placebo and chlorhexidine/PVP rinses. Tongue stain area and intensity were significantly reduced with 5% and 10% PVP/chlorhexidine rinses compared to 0.06% chlorhexidine rinse. CONCLUSION: PVP, at the concentrations tested, reduced the stain propensity of a 0.06% chlorhexidine rinse but at the expense of some loss of plaque inhibition.

Adolescent↗

PubMed2001

The effect of polyvinyl pyrrolidone on the clinical activity of 0.09% and 0.2% chlorhexidine mouthrinses.

BACKGROUND: Previous studies have shown that polyvinyl pyrrolidone (PVP) added to a chlorhexidine rinse reduced extrinsic dental stain but at the expense of a reduction in plaque inhibitory activity. This effect appeared due to a reduction in the effective chlorhexidine dose to levels where dose response studies show plaque inhibition falls off rapidly. The aim of these 2 clinical studies was to determine if PVP could be added to chlorhexidine rinses to maintain efficacy and reduce staining. METHOD: Study 1 involved 42 healthy dentate volunteers and was a blind, randomised, 7 treatment, crossover design balanced for residual effects. The rinses were: 1. 0.09% chlorhexidine to which was added, 2. 1% PVP, 3. 3% PVP, 4. 5% PVP, 5. 7% PVP, 6. Placebo, 7. Essential oil product. Rinses were used 2x on day one of each period after a prophylaxis. Subjects suspended tooth cleaning for 24 h and were then scored for plaque area. Study 2 used the experimental gingivitis model, involved 24 healthy dentate subjects and was a blind, randomised, 3 treatment, crossover design balanced for residual effects. The rinses were 1. 0.2% chlorhexidine, 2. 0.2% chlorhexidine/10% PVP, 3. Placebo. At baseline and the end of each study period subjects were rendered plaque, stain and calculus free, suspended oral hygiene and rinsed 2x per day. Plaque, gingivitis and stain were scored at baseline, 1, 2, and 3 weeks. Calculus was scored at baseline and 3 weeks. RESULTS: Study 1: Buccal plaque scores were significantly lower with all rinses compared to placebo. Also all buccal plaque scores were significantly lower with chlorhexidine and chlorhexidine/PVP rinses compared to the essential oil/phenolic rinse. There were no significant differences between the chlorhexidine rinse and the chlorhexidine/PVP rinses. Analyses for buccal and lingual plaque combined produced, with one exception, the same results for rinse comparisons as for buccal plaque alone. Thus the essential oil/phenolic rinse just failed to reach significance compared to placebo. Study 2: Plaque and gingivitis scores were significantly lower with positive control and test rinses compared to placebo but with no difference between these rinses. Tooth and tongue stain was significantly higher with the positive control and test rinses compared to placebo but not significantly different between these 2 rinses. Calculus scores were not significantly different between the three study rinses. CONCLUSION: Taken with previous data, the balance of evidence does not support PVP as an inhibitor of staining associated with chlorhexidine. These data are further evidence that chlorhexidine oral hygiene products, which, do not or claim not to cause staining, are most probably lacking efficacy.

Adult↗

PubMed2000

Comparison of a double-textured prototype manual toothbrush with 3 branded products. A professional brushing study.

BACKGROUND: The consensus has been that there is no one superior design of manual toothbrush for plaque removal, despite, in some cases, encouraging findings from laboratory studies. The user appears the major variable and may mask differences in brush efficacy. AIMS: The aim of this study was to compare 2 new double-filament texture brushes with 3 established brands for plaque removal, under standardised conditions of professional brushing. METHOD: The study was a blind, randomised crossover design, balanced for residual effects. A panel of 15 subjects suspended tooth cleaning for 3 days. On day 4, plaque was scored from 6 sites per tooth before and after a 2-min professional toothbrushing. A washout period of at least 3 days was allowed between study periods. RESULTS: Overall plaque removal was 50% with no significant differences between brushes, a 3% absolute difference in average total mouth plaque separating brushes. However, at upper- and mid-buccal sites, a not significant 8% and a significant 9% difference, respectively, in plaque removal were recorded in favour of one of the prototype brushes, and at the mid-lingual site, there was a non-significant 10% difference in favour of one branded brush. Other sites were cleaned similarly by all brushes except for reduced plaque removal from buccal compared to lingual surfaces and interproximal compared to mid-surface sites. Highly significant subject differences in plaque removal were noted which may be relevant to inherent anatomical difficulties in tooth cleaning for some individuals. Period effects were not significant, supporting the consistency in brushing by the professional brusher. CONCLUSION: The method appeared capable of detecting small benefits of brush design. However, the benefits reported must be taken within the context of an overall lack of difference between brushes. The method could be used to set and record a minimum level of efficacy for toothbrushes.

Adult↗

PubMed2000

The use of professional brushing to compare 3 toothbrushes for plaque removal from individuals with gingival recession.

BACKGROUND: Toothbrush filament configuration now varies considerably, usually with the intention of improving plaque removal overall or from specific sites. AIMS: The aim of the study was to compare 2 branded toothbrushes with a brush designed with a convex filament head arrangement to improve plaque removal from teeth with buccal gingival recession. METHODS: The study was a randomised, 3-treatment, double-blind crossover design balanced for residual effects and involving 18 healthy volunteers. On day 1, subjects suspended toothcleaning and returned to the clinic on day 4. Plaque was scored by area and index before and after 2 min of toothbrushing with the allocated brush. Brushing was performed by a hygienist allocating a timed 15 s to each of the 8 buccal and lingual quadrants. 3 days was allowed between treatment periods. RESULTS: Plaque accumulation differed considerably by site as did plaque removal. Overall plaque removal was 40%. Analysis showed significant subject differences but, no significant period or treatment differences. CONCLUSIONS: Consistent with other reports, it must be concluded that brush design is not a major variable in plaque removal. However using this "robot"-like model, the dentition of some individuals and specific dental surfaces are inherently more difficult to clean than others.

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↗

PubMed1996

An evaluation of an antiadhesive copolymer agent on plaque inhibition by chlorhexidine.

The high molecular weight copolymer M239144 has proven antiadhesive action in vitro but clinically lacked effect, even when combined with chlorhexidine. This latter result was thought to arise from inactivation of chlorhexidine by the copolymer. The aim of this study was to determine whether improved activity might arise if the copolymer and chlorhexidine were applied sequentially rather than combined. The study was a double-blind, randomised crossover design balanced for carryover using a 24-h plaque regrowth method. 2 groups of 25 subjects from a zero plaque baseline rinsed 1x with 15 ml volumes of the allocated paired rinses for 60 s. Subjects abstained from toothcleaning for 24 h and were scored for plaque by area. The paired regimens were: 1. placebo: placebo; 2. placebo: 0.03% chlorhexidine; 3. 1% co-polymer and 0.03% chlorhexidine; 4. placebo: 1% co-polymer; 5. placebo: 0.12% chlorhexidine. Plaque regrowth was greatest with regimen 1 and least with regimen 5. However, regimens 3 and 4 were not significantly different from regimen 1, whereas regimen 2 was significantly more effective than regimen 3. The results indicate that the copolymer alone is ineffective, and even delivered sequentially, inactivates chlorhexidine.

Anti-Infective Agents, Local↗

PubMed1996

Comparative single-use plaque removal by toothbrushes of different designs.

Overall literature reviews have concluded that no one design of the manual toothbrush is superior for plaque removal. More recently, a toothbrush with filaments angled away from the head was shown to be more effective in several single-use studies than conventional designs. The aim of this study was to compare plaque removal by this new toothbrush and 3 other toothbrushes which had more conventional filament arrangements. 36 volunteers participated in this single-blind, randomised, 4-cell, crossover single use toothbrushing study. On day 1 of each period, volunteers brushed with a standard toothbrush and toothpaste for 60 s and then suspended oral hygiene for 48 h. On day 3, volunteers were scored for plaque by area and then brushed with the allocated test toothbrush with toothpaste for 60 s and plaque area was rescored. A washout of 4 days was allowed between test periods. The plaque areas were used to record the binary scores of the Rustogi et al. modification of the modified Navy plaque index but away from the clinic employing the Claydon and Addy procedural method for the index. Plaque removal scored by area and site were not significantly different between the brushes. This study is at variance with previous similar investigations which suggested that the new design of toothbrush head was superior for plaque removal. It is concluded again that there are no data which demonstrate unequivocally that any one manual toothbrush design is superior to any other for plaque removal.

Adult↗

PubMed1996

A 6-month home-usage trial of 0.1% and 0.2% delmopinol mouthwashes (I). Effects on plaque, gingivitis, supragingival calculus and tooth staining.

Delmopinol is a morpholinoethanol derivative which, in mouthrinses used in the absence of normal oral hygiene, has been shown effective in the inhibition of plaque and gingivitis. The aim of this study was to determine the adjunctive oral hygiene benefits and safety of delmopinol rinses when used alongside normal toothcleaning. This 6-month home use study was a placebo-controlled, double-blind, randomised parallel design evaluating 0.1% and 0.2% delmopinol rinses and structured to conform with the ADA Council of Dental Therapeutics guidelines. A total of 450 dentate male and female subjects were recruited who had no relevant medical or pharmacotherapy histories determined from a full medical examination, including haematological and biochemical tests. Subjects had moderate levels of plaque and gingivitis. At baseline, 3 and 6 months subjects were scored for plaque, gingivitis, tooth stain and supragingival calculus, with plaque sampled for microbiological analysis. Additionally, oral mucosal examinations were performed and subjects questioned for adverse symptoms. Baseline special tests were repeated at the end of the study. After baseline examinations, the subjects received a professional prophylaxis, provided with the allocated mouthwash and instructed to use 10-ml volumes for 60 s 2 x daily and where appropriate after toothbrushing and meals. Demographic features of the 3 groups were similar and losses to trial were small. Adverse signs and symptoms included transitory numbness of the tongue, tooth and tongue staining, taste disturbance and rarely mucosal soreness and erosion. All local side-effects were less commonly reported at 6 compared to 3 months and only 6 subjects were withdrawn because of adverse event. No systemic effects attributable to the agent were observed and no significant shifts in haematological or biochemical parameters occurred. All groups showed considerable improvements in oral hygiene and gingival health with some significant differences in favour of 0.2% delmopinol compared to placebo for gingivitis and more particularly plaque. Staining was also significantly increased in the delmopinol groups but not calculus. In the present study, a considerable Hawthorne effect occurred, which must in part explain why only a modestly significant effect was achieved.

Adult↗

PubMed1995

The use of plaque area and plaque index to measure the effect of fluoride and chlorhexidine toothpastes on 24-h plaque regrowth.

Short-term methodologies have been developed to screen chemical agents for plaque inhibitory effects. Most measure inhibition of plaque regrowth over several days. A method was described to study agents over 16-24 h periods, although some difficulties with the index used were reported. The aim of this study was to determine whether more conventional plaque scoring methods could be used. These 2 crossover studies measured plaque regrowth over 24 h in 20 subjects and in response to single brushings with either a chlorhexidine and minus active toothpaste or to a fluoride toothpaste product and water. Significantly less plaque had reformed after brushing with the chlorhexidine toothpaste compared with its control and with the fluoride toothpaste compared with water. 18 subjects participated in both studies and using their data for an interstudy comparison, less plaque developed with the chlorhexidine compared with the fluoride toothpaste. These studies had the advantage that longer-term trials already demonstrated the same differences. This permits one to conclude with some certainty that the 24-h plaque regrowth study design, using conventional measures of plaque accumulation, could be a useful and rapid method of screening potential plaque inhibitory agents and formulations.

Anti-Infective Agents, Local↗

PubMed1995

The use of planimetry to record and score the modified Navy index and other area-based plaque indices. A comparative toothbrush study.

Many plaque-scoring methods are based on a subjective assessment of the amount of tooth surface covered by plaque or the presence or absence of plaque at specific sites. The 2x modified Navy plaque index is an example of the latter and requires chairside decisions from 9 zones of all buccal and lingual tooth surfaces, i.e., up to 576 for a complete dentition. The present study describes a procedural modification to the index, whereby plaque is recorded using an established planimetric plaque area method. Scoring is then performed using an overlay away from the clinic. To test the method, plaque-area measurements were made during a 30-subject, crossover study to compare plaque removal following single toothbrushings with 3 different types of manual toothbrush. Consistent with many such studies, no significant differences in plaque removal were noted between the brushes. The method was found quick and simple at the chairside, provided a permanent record of plaque distribution and could be analysed by clinical or nonclinical personnel under ideal conditions. The same method could be employed for other plaque indices based on area or site subjective decisions.

Cross-Over Studies↗

PubMed1987

The CaATPase activity of rat-incisor odontoblast vesicles.

An homogenate of rat incisor odontoblasts had Ca2+ and Mg2+ ATPase activity and suitable storage conditions kept it stable for several days. Over 90 per cent of the activity was retained in a vesicle-rich microsomal fraction that removed about 85 per cent of the total material from the homogenate. This fraction was further characterized: the resolved Ca2+-activated ATPase activity, above the basal MgATPase activity, was 0.30 mumol Pi/min-mg total protein, and 50 per cent activated at free [Ca2+] equal 0.8 microM. This calcium dependency is consistent with an intracellular Ca2+-regulated enzymatic activity. The calcium ionophore, A23187, had no measurable effect on the CaATPase activity, which suggests that the odontoblast vesicles do not concentrate Ca2+ in a lipid bilayer compartment. Direct measurement of the uptake of 45Ca2+ by the filtration method and parallel measurements of CaATPase activity on the same preparations under identical conditions indicated that the odontoblast-derived vesicles have a coupling ratio of 0.024 Ca2+/ATP. This low coupling ratio and the lack of detectable compartmentalization of calcium indicate that the CaATPase activity of the odontoblast microsomes is not associated with a calcium pump. The [Ca2+] dependence of the activity suggests the CaATPase is under intracellular Ca2+ control, but its function is unknown.

Animals↗