Search PubMed⌕ Search

Biomedical subjects

R G Newcombe

Publications and source records attributed to R G Newcombe.

At least 73 records · Page 4Linked to original sources
PubMed2001

Improving oral health in institutionalised elderly people by educating caregivers: a randomised controlled trial.

OBJECTIVES: This cluster-randomised controlled trial assessed whether oral health care education (OHCE) for nursing home caregivers would achieve improvements in clients' oral health. METHODS: Twenty-two nursing homes were randomly allocated to intervention or control group. Clients were examined at baseline and at follow-up visits 1- and 6-months after caregivers received OHCE. Main outcome measures were denture plaque, denture-induced stomatitis, dental plaque and gingivitis. Differences in group means/medians were compared with adjustment for cluster randomisation. RESULTS: Clients' baseline oral health was poor. After OHCE, the intervention group's oral health scores improved significantly. Reductions in denture plaque scores (0-4 scale) exceeded those of the control group by 1.15 (95%CI=0.83, 1.47) at 1 month and by 1.47 (95%CI=1.13, 1.80) at 6 months. Denture-induced stomatitis prevalence reduced significantly over 6 months compared to the control group (P<0.0001). Group differences in favour of the intervention group were 0.41 (95%CI=0.18, 0.65) at 1 month and 0.34 (95%CI=0.14, 0.53) at 6 months for dental plaque (0-3 scale), and 0.17 (95%CI= -0.01, 0.35) at 1 month and 0.28 (95%CI 0.15, 0.42) at 6 months for gingivitis (0-2 scale). Key differences remained significant after adjustment for clustering effects. The provider's costs would currently be approximately pounds 6700 per year to deliver the intervention to a Health Authority with 100 homes. CONCLUSIONS: Although final levels of residents' oral health were still short of ideal, this study clearly shows that, for a modest cost, OHCE can improve caregivers' knowledge, attitudes and oral health care performance for elderly, functionally dependent clients.

Aged↗
PubMed2001

Nerve morbidity following wisdom tooth removal under local and general anaesthesia.

Two hundred and one patients had unilateral removal of the lower third molars under local anaesthesia and a further 234 patients had either bilateral or unilateral removal under general anaesthesia. A total of 634 lower third molars were extracted by four experienced surgeons (two consultants and two senior grade staff). All patients were reviewed independently 1-week postoperatively and any sensory disturbance and its location was recorded. Patients with sensory disturbance were subsequently reviewed at 1 month and again at 6 months if recovery was not complete. This study demonstrated little difference in the adverse event rate per tooth extracted between procedures under local and general anaesthesia. However, within the general anaesthetic group, the few unilateral procedures showed evidence of higher risk, but the number was too small for valid satisfactory analysis. The risk of nerve morbidity was also greater where the duration of the procedure was longer than 15 minutes in unilateral cases.

Adult↗
PubMed2001

A comparative study of peer-led and adult-led school sex education.

There are, and have been, many school-based sex education projects in this country which have used peer leaders (students delivering an educational programme who are of similar, or slightly older, age than the students receiving the programme). Rigorous evaluation of the methodology remains scant. This paper describes a comparative investigation of peer-led and adult-led sex education in National Curriculum Year 9 (aged 13/14 years). The results from this study suggest that peer leaders appear to be more effective in establishing conservative norms and attitudes related to sexual behaviour than the adults. Peer leaders were less effective than adults in imparting factual information and getting students involved in classroom activities. These findings suggest that both adult-led and peer-led methods may have a place in effective sex education--the challenge being to determine which areas are best dealt with by whom.

Adolescent↗
PubMed2001

Controlled randomised crossover trial of the effects of physiotherapy on mobility in chronic multiple sclerosis.

OBJECTIVES: To determine whether physiotherapy can improve mobility in chronic multiple sclerosis and whether there is a difference between treatment at home and as a hospital outpatient? METHODS: A randomised controlled crossover trial was undertaken in patients with chronic multiple sclerosis who had difficulty walking and were referred from neurology clinics: allocation was to one of six permutations of three 8 week treatment periods separated by 8 week intervals: treatments consisted of physiotherapy at home, as an outpatient, or "no therapy". The main outcome measures were based on independent assessments at home and included mobility related disability (primary outcome: the Rivermead mobility index), gait impairments, arm function, mood, and subjective patient and carer ratings. Therapy was assessed by recording delivery, achievement of set targets, patient and carer preference, and cost. RESULTS: On the Rivermead mobility index (scale 0-15) (primary outcome) there was a highly significant (p<0.001) treatment effect of 1.4-1.5 units favouring hospital or home based therapy over no therapy: this was supported by other measures of mobility, gait, balance, and the assessor's global "mobility change" score: there was no major difference between home and hospital. Carers preferred home treatment but neither they nor patients discerned greater benefit there. Estimated costs of home physiotherapy were 25 pounds/session and those at hospital were 18 pounds (including 7 pounds patient travel costs). CONCLUSION: A course of physiotherapy is associated with improved mobility, subjective wellbeing, and improved mood in chronic multiple sclerosis compared with no treatment but benefit may only last a few weeks: there is little to choose between home and hospital based therapy but the first is more costly, mainly due to skilled staff travelling time.

Adult↗
PubMed2001

Folate improves endothelial function in coronary artery disease: an effect mediated by reduction of intracellular superoxide?

Homocysteine is a risk factor for coronary artery disease (CAD). Folic acid lowers homocysteine and may improve endothelial function in CAD, although the mechanism is unclear. We investigated the effect of folic acid on endothelial function, homocysteine, and oxidative stress in patients with CAD. We also examined the acute effect of 5-methyltetrahydrofolate (5-MTHF), the principal circulating folate, on endothelial function in vivo and on intracellular superoxide in cultured endothelial cells. A randomized crossover study of folic acid (5 mg daily) for 6 weeks was undertaken in 52 patients with CAD. Ten further patients were given intra-arterial 5-MTHF. Endothelial function was assessed by flow-mediated dilatation (FMD). Folic acid increased plasma folate (P<0.001), lowered homocysteine by 19% (P<0.001), and improved FMD (P<0.001). FMD improvement did not correlate with homocysteine reduction. Malondialdehyde and total plasma antioxidant capacity, markers of oxidative stress, were unchanged. 5-MTHF acutely improved FMD (P<0.001) without altering homocysteine (P=0.47). In vitro, 5-MTHF abolished homocysteine-induced intracellular superoxide increase (P<0.001); this effect was also observed with folic acid and tetrahydrobiopterin. Our data support the beneficial effect of folic acid on endothelial function in CAD but suggest that the mechanism is independent of homocysteine. Reduction of intracellular endothelial superoxide may have contributed to the effect.

Animals↗
PubMed2000

The chemical stain removal properties of 'whitening' toothpaste products: studies in vitro.

BACKGROUND: A considerable number of toothpastes are available as tooth whitening products. Most appear to contain ingredients that might remove extrinsic stains rather than change natural tooth colour. Extrinsic stain removal could be achieved by physical or chemical means. AIM: The purpose of this study was to measure the chemical stain removal properties of a range of whitening toothpaste products and experimental formulations using a standardised method in vitro. MATERIALS AND METHOD: 5 separate studies were conducted involving a total of 39 agents of which 28 were whitening products, 7 were experimental formulations, 2 were oxidising mouthrinses used as positive controls, 1 was a popular fluoride toothpaste product as a benchmark control, and 1 was water as the negative control. The formulations and controls varied in each study. The stain model was saliva/chlorhexidine/tea stain developed on optically clear acrylic to an optical density of at least 2.0. Groups of stained specimens were exposed to standard slurries or solutions of each test agent for 1 minute periods up to 5 minutes. Optical density readings were taken at each 1 minute time point. Analyses were based on per cent stain remaining after 5 minutes and time to 75% stain remaining. RESULTS: 3 toothpaste products achieved 100% stain removal by 5 minutes; 2 of these in 3 out of 4 studies in which they were used. 4 experimental formulations also achieved 100% stain removal. In general agents with high total stain removal also had short times to 75% stain remaining. The majority of agents tested had low total chemical stain removal and prolonged times to 75% stain remaining. A few agents were little different from water and several similar in effect to the conventional fluoride toothpaste. This method in vitro tests agents under the best case scenario conditions for chemical stain removal. CONCLUSION: Only a small number of the whitening toothpaste products have good chemical stain removal potential; the majority are unlikely to achieve their claimed benefits through chemical stain removal. There is clearly a need for further data on the actual effects of such products using both methods in vitro and particularly in vivo or in situ.

Acrylic Resins↗
PubMed2000

Risk factors in the development of cyclosporine-induced gingival overgrowth.

BACKGROUND: Severe gingival hyperplasia (GH) is one of the most frequent side-effects associated with the prescription of cyclosporine-A (CsA). Using the largest group of renal allograft recipients assembled for this purpose, in this study, we statistically modeled the genetic (HLA), medical, and dental risk factors for the development of GH subsequent to administration of CsA. METHODS: Two hundred thirty-six renal transplant patients underwent full dental examination to quantify the extent and distribution of hyperplasia and dental disease (gingivitis, plaque, and calculus). Computerized data from all patients included pre-transplant medical history and dosage of nifedipine and azathioprine, as well as dose and serum levels of CsA and CsA microemulsion. Donor and host HLA haplotype were studied to investigate potential association of haplotype and donor-host mismatching with the development of GH. We evaluated the data by multivariate regression analysis, using Statistical Package for Social Sciences (SPSS). RESULTS: There was no association with age, sex, duration of renal replacement therapy, or interval since transplantation or pre-transplant disease (P>0.05). There also was no association of disease with host HLA haplotype, but degree of HLA-A mismatching was protective for GH development (P<0.002). GH was associated with the dose and serum levels of CsA (P<0.001) and the last dose of CsA microemulsion (P=0.009) but not nifedipine (P=0.10). Gingival inflammation and plaque were also strongly associated with GH (P<0.0003). In multivariate analysis, however, the last recorded dose of CsA (P<0.0001), presence of local gingival inflammation (P<0.0001), and gingivitis (P<0.003) were the independent predictors of the extent and severity of GH. CONCLUSIONS: Inter-patient variation in the extent and severity of GH is related to CsA dose and serum levels. Differences in host HLA phenotype do not explain individual susceptibility to GH, but donor-host HLA-A mismatching may be important. Inter-site variation in the extent and severity of the disease is related to local gingival inflammation.

Adolescent↗
PubMed2000

Results at 1 year of outpatient multidisciplinary pulmonary rehabilitation: a randomised controlled trial.

BACKGROUND: Pulmonary rehabilitation seems to be an effective intervention in patients with chronic obstructive pulmonary disease. We undertook a randomised controlled trial to assess the effect of outpatient pulmonary rehabilitation on use of health care and patients' wellbeing over 1 year. METHODS: 200 patients with disabling chronic lung disease (the majority with chronic obstructive pulmonary disease) were randomly assigned a 6-week multidisciplinary rehabilitation programme (18 visits) or standard medical management. Use of health services was assessed from hospital and general-practice records. Analysis was by intention to treat. FINDINGS: There was no difference between the rehabilitation (n=99) and control (n=101) groups in the number of patients admitted to hospital (40 vs 41) but the number of days these patients spent in hospital differed significantly (mean 10.4 [SD 9.7] vs 21.0 [20.7], p=0.022). The rehabilitation group had more primary-care consultations at the general-practitioner's premises than did the control group (8.6 [6.8] vs 7.3 [8.3], p=0.033) but fewer primary-care home visits (1.5 [2.8] vs 2.8 [4.6], p=0.037). Compared with control, the rehabilitation group also showed greater improvements in walking ability and in general and disease-specific health status. INTERPRETATION: For patients chronically disabled by obstructive pulmonary disease, an intensive, multidisciplinary, outpatient programme of rehabilitation is an effective intervention, in the short term and the long term, that decreases use of health services.

Aged↗
PubMed2000

Perceived risk of future pathology associated with pathology-free third molars: a comparison of oral and maxillofacial surgeons and family dentists.

OBJECTIVE: To examine and compare practitioners' judgements of risk of future pathology associated with pathology-free disease asymptomatic third molars. SUBJECTS: 10 oral and maxillofacial surgeons and 18 family dentists (90% male) with experience ranging from 5-28 years. METHOD: Participants were presented with periapical radiographs of 36 asymptomatic, disease-free mandibular third molars and were informed of the age and sex of the patients and the degree of eruption of the third molars. Participants were asked to assess likelihood of future pathology in general, and more specifically, likelihood of root resorption, pericoronitis, periodontitis, cystic change and neoplasia if the third molar was left in situ. RESULTS: There was significant variation between the 28 raters but not between the two groups. Excepting assessment of future cystic change, there was no evidence that oral and maxillofacial surgeons and family dentists rated the 36 cases in consistently different ways. CONCLUSIONS: Practitioners varied very considerably in their judgment of the risks of pathology associated with asymptomatic disease-free third molars. Specialisation, did not account for this variation.

Adult↗
PubMed2000

Relative susceptibility of deciduous and permanent dental hard tissues to erosion by a low pH fruit drink in vitro.

OBJECTIVES: The objectives of this study were two-fold: (1) to determine (by surfometry) loss of deciduous and permanent enamel and dentine following 15days' exposure to a single low pH orange drink; and (2) to determine (by surfometry) loss of deciduous and permanent enamel and dentine following exposure to the product 2 versus 4 times per day for 15days. METHODS: This in vitro study employed the validated methodology described by West and co-workers [Journal of Dentistry, 1998;26:329-335.] RESULTS: In all four tissues, erosion was progressive over time, though this pattern was more linear in enamel than in dentine. In general, erosion of enamel was greater in the deciduous tissue, while erosion of dentine was greater in the permanent tissue. However, these differences were rarely of statistical significance. Increasing frequency of exposure resulted in a non-proportional increase in tissue loss. CONCLUSIONS: Differences in susceptibility of deciduous and permanent tissues to erosion by a low pH drink in vitro appear to exist, though these may not be of statistical significance. Care may be indicated in the delivery of dietary advice, since reduced frequency of exposure to a low pH drink does not appear to result in a proportional reduction in tissue loss.

Adolescent↗
PubMed2000

Erosion of deciduous and permanent dental hard tissue in the oral environment.

OBJECTIVES: The objectives of this study were two-fold: (1) to determine (by surfometry) loss of deciduous and permanent enamel and dentine following consumption of a single low pH orange drink for 15days; and (2) to determine (by surfometry) loss of deciduous and permanent enamel and dentine following consumption of the product 2 versus 4 times per day for 15days. METHODS: Sixteen healthy volunteers participated in a single centre, single blind, 2-phase crossover study, conducted according to Good Clinical Practice, and employing the validated model described by West and co-workers (Journal of Dentistry 1998; 26:329-335). RESULTS: In all tissues, erosion was progressive over time, the pattern being more linear in enamel than in dentine. In general, erosion of deciduous enamel was greater than that of permanent enamel, though this difference was significant only for those specimens exposed to 4 drinks per day. Conversely, erosion of dentine was generally greater in the permanent tissue, though differences rarely reached conventional levels of statistical significance. Increasing frequency of consumption resulted in increased loss of tissue, but this difference was neither proportional nor consistently statistically significant. CONCLUSIONS: It is concluded that statistically significant differences in susceptibility of deciduous and permanent enamel to erosion appear to emerge over time and with increasing frequency of consumption. This is of importance clinically given the reduced dimensions of the deciduous dentition and the element of 'abuse' of soft drinks by the child population. Further development of soft drinks with low erosive potential is recommended.

Adult↗
PubMed2000

Comparative effects of quaternary ammonium mouthrinses on 4-day plaque regrowth.

BACKGROUND: Quaternary ammonium compounds constitute a large group of antibacterial chemicals with a potential for inhibiting plaque and gingivitis. One compound, benzalkonium chloride (BC), may be of value, although there is a dearth of evidence to support efficacy. The aim of this study was to measure the ability of 2 BC mouthrinses (0.05% and 0.1%) to inhibit de novo plaque reformation. METHOD: A 4-day plaque regrowth model. For comparative purposes, a commercial mouthrinse containing cetyl pyridinium chloride (CPC) and a positive control chlorhexidine (CX) mouthrinse were also evaluated. RESULTS: Compared to water control, a reduction in plaque scores of 52% was noted for the CX mouthrinse, 22.5% for CPC and 5% and 6% for the 2 BC rinses. For plaque area, reductions of 84%, 47%, 16% and 15% were found for CX, CPC, and the 2 BC rinses, respectively. Significant reductions in plaque area compared to the water rinse were also seen with the 2 BC rinses (p<0.05). However, for both plaque score and plaque area, the CX and CPC rinses significantly reduced plaque compared to the BC rinses (p<0.0001). CONCLUSIONS: These findings would suggest that the 2 benzalkonium rinses would only have a limited value at inhibiting plaque formation.

Analysis of Variance↗
PubMed2000

Studies in vitro of abrasion by different manual toothbrush heads and a standard toothpaste.

BACKGROUND: Loss of dentine at the buccal cervical region of teeth has a multifactorial aetiology. However, a considerable amount of circumstantial evidence, supported by laboratory experiments, implicates toothbrushing with toothpaste as a consistent factor. Most interest has centred around the abrasivity of toothpastes, particularly since a toothbrush alone has negligible effects on dentine. The influence of filament stiffness on toothpaste abrasion was the subject of some studies, mostly at least 2 decades ago, and produced conflicting conclusions. Numerous changes to toothbrush design and construction have taken place in recent years. AIMS: The aim of this study was to measure the abrasion of a standard substrate, acrylic, by a standard toothpaste carried on modern brands of toothbrushes classified by manufacturers as hard (3 brands), medium (3 brands) and soft (6 brands). METHOD: The substrate was brushed for 20,000 strokes with at least 6 heads from each brand. Measurements of substrate loss were made at 5000 stroke increments by profilometry. RESULTS: Substrate loss for all brushes showed a pattern of abrasion which was to a first approximation linear. Overall, hard brushes caused least abrasion and soft brushes the most, with differences between groups being significant. Within-group differences between brands reached significance for soft and medium brushes but not hard brushes. CONCLUSIONS: The results could be explained by increased retention of toothpaste by smaller diameter filaments and denser tufts on soft brushes and the greater flexion of filaments increasing the area of contact with the surface. Calculations on the clinical outcome of these data in vitro indicate that toothbrushing with toothpaste alone would produce minimal damage to dentine even over many years. Differences between brushes therefore are probably of little clinical significance. Certainly, the data do not support the use of hard brushes, particularly in view of the potential detrimental effects to gingival tissues.

Hardness↗
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↗
PubMed2000

A study to assess the plaque inhibitory activity of a new triclosan mouthrinse formulation.

BACKGROUND/AIMS: Toothpastes and mouthrinses containing triclosan have been shown to be of some value at inhibiting both plaque and gingivitis. However much improved activity can be obtained by the addition of other chemicals which increase substantivity or antimicrobial activity. The present study was designed to determine whether a new mouthwash formulation containing a triglyceride oil was capable of reducing plaque reformation when compared to a control rinse containing neither triclosan or oil. METHODS: A total of 24 subjects took part in a double-blind, single-centre, cross-over study in which rinses were used as the only form of oral hygiene over a 4-day period. On the 1st day of each period, the subjects were given a prophylaxis to remove all plaque and calculus deposits. A single supervised rinse was taken and subsequent 2x daily rinses over the following 3 days. 24 and 96 h after the prophylaxis, the volunteers returned to the clinic, the plaque disclosed and assessed by plaque index and area. The test procedure and wash-out phase were repeated until all of the subjects had used both rinses. RESULTS: After 24 h, a 12% reduction in plaque score and a 25% reduction in plaque area was noted for the triclosan/oil rinse compared to the control rinse; however, these reductions were not significant (p>0.05). After 96 h, the triclosan/ oil rinse failed to produce a numerical or statistical reduction in plaque whether measured by plaque score or area. CONCLUSIONS: These findings would suggest that the triclosan/oil rinse would be of little value at inhibiting dental plaque whether used alone or as an adjunct to conventional oral hygiene measures.

Adult↗