Quality and content of dental practice websites.

AIMS AND OBJECTIVES: To investigate the quality and content of dental practice websites by constructing an audit framework based on regulations, guidance and expert advice, and applying this framework to a random sample of UK dental practices' websites. METHODS: An audit framework was constructed and in-depth data collected from a random sample of 150 UK dental practices. RESULTS: Thirty-five percent of dental practices in this study were found to have websites. Compliance with rules and regulations regarding dental practice websites was generally poor. Use of advised content for practice promotion was variable. Many websites were poorly optimised. Eighty-nine percent of the websites advertised tooth whitening, despite the issues surrounding its legality; 25% of the websites advertised Botox even though advertising of prescription only medicines is illegal. Some websites gave misleading information about the specialist status of their dentists. CONCLUSIONS: Those responsible for dental practice websites need to be aware of a wide range of regulations and guidance, and are advised to follow expert advice on content and optimisation in order to maximise the potential of their websites.

A new, highly selective murine peroxisome proliferator-activated receptor δ agonist increases responsiveness to thermogenic stimuli and glucose uptake in skeletal muscle in obese mice.

AIM: We investigated how GW800644, the first pharmacologically selective murine peroxisome proliferator-activated receptor δ (PPARδ) agonist, affects energy balance, glucose homeostasis and fuel utilization by muscle in obese mice. METHODS: Potencies were determined in transactivation assays. Oral glucose tolerance was determined after 14 and 22 days' administration (10 mg/kg body weight, twice daily) to Lep(ob)/Lep(ob) mice. Food intake and energy expenditure were measured during a 26-day experiment, and plasma metabolites and 2-deoxyglucose uptake in vivo at termination. Palmitate oxidation and 2-deoxyglucose uptake by isolated soleus muscles were measured after 14 (in lean and obese mice) and 26 days. RESULTS: GW800644 activated murine PPARδ (EC(50) 2 nM), but caused little to no activation of PPARα or PPARγ up to 10 µM. It did not increase liver weight. GW800644 reduced food intake and body weight in obese mice after 8 days. It did not affect resting energy expenditure, but, compared to pair-fed mice, it increased the response to a ß(3)-adrenoceptor agonist. It improved glucose tolerance. GW800644, but not pair-feeding, reduced plasma glucose, insulin and triglyceride concentrations. It increased 2-deoxyglucose uptake in vivo in adipose tissue, soleus muscle, heart, brain and liver, and doubled 2-deoxyglucose uptake and palmitate oxidation in isolated soleus muscle from obese but not lean mice. CONCLUSIONS: PPARδ agonism reduced food intake and independently elicited metabolic effects that included increased responsiveness to ß(3)-adrenoceptor stimulation, increased glucose utilization and fat oxidation in soleus muscle of Lep(ob)/Lep(ob) but not lean mice and increased glucose utilization in vivo in Lep(ob)/Lep(ob) mice.

Inhibition of atherosclerosis in apolipoprotein-E-deficient mice following muscle transduction with adeno-associated virus vectors encoding human apolipoprotein-E.

Apolipoprotein E (apoE) is a multifunctional plasma glycoprotein involved in lipoprotein metabolism and a range of cell signalling phenomena. ApoE-deficient (apoE(-/-)) mice exhibit severe hypercholesterolaemia and are an excellent model of human atherosclerosis. ApoE somatic gene transfer and bone marrow transplantation in apoE(-/-) mice results in reversal of hypercholesterolaemia, inhibition of atherogenesis and regression of atherosclerotic plaque density. Replication defective adeno-associated virus vectors (rAAVs) are an attractive system currently in clinical trial for muscle-based heterologous gene therapy to express secreted recombinant plasma proteins. Here we have applied rAAV transduction of skeletal muscle to express wild-type (epsilon3) and a defective receptor-binding mutant (epsilon2) human apoE transgene in apoE(-/-) mice. In treated animals, apoE mRNA was present in transduced muscles and, although plasma levels of recombinant apoE fell below the detection levels of our ELISA (ie <10 ng/ml), circulating antibodies to human apoE and rAAV were induced. Up to 3 months after a single administration of rAAV/apoE3, a significant reduction in atherosclerotic plaque density in aortas of treated animals was observed (approximately 30%), indicating that low-level rAAV-mediated apoE3 expression from skeletal muscle can retard atherosclerotic progression in this well-defined genetic model.

Case report: the transmandibular implant system.

This series of case reports outlines the use of the transmandibular implant system to rehabilitate 10 patients with severely resorbed mandibles. The implants were placed according to manufacturers' guidelines with the patient under a general anaesthetic and reviewed bi-annually thereafter. Three patients experienced problems: in two of these this involved the loss of integration of the distal posts, in the other patient the transmandibular implant was removed in its entirety. Distal locking screws became loose shortly after placement in three patients. Prosthetic complications included difficulty in obtaining passive fit of the superstructure in 7 patients and a high long-term maintenance commitment.

The sealant restoration: indications, success and clinical technique.

In this paper we have considered the available literature which demonstrates that sealant restorations perform at least as well as amalgam restorations and are more conservative. Success depends on retention of the overlying sealant and if this is fully retained it is unlikely that any residual caries will progress. The diagnosis of occlusal caries and indications for sealant restorations are discussed and the clinical technique is described. We have concluded that sealant restorations are the optimum restoration in small and discrete occlusal cavities.

An investigation into sealant restoration usage in general dental practice in England.

AIM: A study was undertaken to investigate attitudes to sealant restorations and their usage in general dental practice in England. METHOD: Seventy three dentists in three areas (Doncaster, Hereford/Worcester and Wycombe) provided retrospective details of treatment provided over a one year period for 4,250 6-12 and 13-15 year old subjects. Fifty nine of these dentists then completed a telephone questionnaire relating to their treatment patterns and attitudes to sealant restorations. RESULTS: The treatment data indicated that only 59 of the 4,250 children received a sealant restoration during the study period. Of the 44 dentists who claimed in the questionnaire to be using sealant restorations, only 28 had placed them in their selected patients. CONCLUSIONS: Positive attitudes to sealant restorations were expressed but also concerns that may be prejudicing usage.

Intramuscular injection of a plasmid vector expressing human apolipoprotein E limits progression of xanthoma and aortic atheroma in apoE-deficient mice.

Apolipoprotein-E (apoE) protects against coronary artery disease via hepatic removal of atherogenic remnant lipoproteins, sequestration of cholesterol from vessel walls and local anti-oxidant, anti-platelet and anti-inflammatory actions. ApoE gene transfer may thus ameliorate a hyperlipidaemic profile and have beneficial effects at lesion sites to prevent or regress atherosclerosis, a concept endorsed by adenoviral-mediated hepatic expression studies. Here, using plasmid vectors expressing allelic human apoE2 or apoE3 isoforms, skeletal muscle was evaluated as an effective secretory platform for apoE gene augmentation. Transfected myoblasts and myotubes were found to efficiently secrete recombinant apoE in vitro as spherical 10-16 nm lipoprotein particles with pre-beta mobility. Intramuscular plasmid injection in apoE(-/-) mice, which develop spontaneous atherosclerotic plaque and xanthoma resulted in expression and secretion of apoE. Human apoE mRNA was detected by RT-PCR in injected muscles and, although concentrations of apoE3, which is rapidly cleared from plasma, were near ELISA detection limits, levels of plasma apoE2 were measurable (17.5 +/- 4.3 ng/ml). To assess whether muscle-based expression of apoE2 could inhibit atherogenesis, long-term follow-up studies were conducted. Although hyperlipidaemia was not reduced in treated animals, end-point pathology showed clear retardation of atherosclerotic and xanthomatous lesions. Up to 9 months following a single apoE2 plasmid administration, atherosclerotic lesion coverage in proximal aorta was significantly reduced by 20-30% (P < 0.01), whereas development of gross dorsal xanthoma (>5 mm diameter) was effectively reduced to zero. We conclude that expression of apoE from ectopic muscle sites has therapeutic potential to limit progression of atherosclerosis.

PPAR agonists as direct modulators of the vessel wall in cardiovascular disease.

Successful management of cardiovascular (CV) disease and associated metabolic syndromes, such as diabetes, is a major challenge to the clinician. Reducing CV risk factors, such as abnormal lipid profiles, insulin resistance or hypertension is the foundation of such therapy. A relatively new class of therapeutic agent, activators of peroxisome proliferator-activated receptors (PPAR), is poised to make a major impact with regard to several areas of risk factor management. However, there is growing evidence that PPAR agonists may also influence the CV system directly by modulating vessel wall function. These observations suggest that additional benefit, in the treatment of CV disease, may derive not only from the ability of agents to modify risk factors but also to influence directly the cellular mechanisms of disease within the vessel wall. A precedent for this dual action comes from examination of the effects of inhibitors of HMG CoA reductase (statins), where risk factor modulation is accompanied by direct actions on the vessel wall. In this review, we summarize the evidence suggesting that PPAR agonists may directly modulate vessel wall function, and that these may parallel those effects reported recently for the statins.

A chemomechanical method for caries removal.

Over recent years the dental profession has shifted towards practising preventive dentistry and adopting more conservative and tooth-preserving procedures. Such progression is considered to be a response to the decline in the level of dental caries and advances in materials science. This shift in caries management will no doubt continue over the coming decades, based on rational clinical and scientific principles. Chemomechanical caries removal involves the application of a solution that selectively softens the carious dentine, thus facilitating its removal. This limits the removal of sound tooth structure, the cutting of open dentinal tubules, pulpal irritation and pain compared with conventional mechanical methods.

Prevalence and attitudes to fissure sealants in the general dental service in England.

OBJECTIVES: The study objectives were to investigate changes in the prevalence of fissure sealants over a 5-year period among a comparable group of 14-15-year-old regular dental attenders registered with general dental practitioners in 1989 and 1994, and to investigate attitudes towards this form of care amongst general dental practitioners in 1994. METHODS: Random samples of 14-15-year-old pupils were selected from school lists in three areas in England (Doncaster, Hereford/Worcester and Wycombe) in 1989 and 1994. Once parental consent had been gained to examine the children, the Dental Practice Board (DPB) indicated which subjects were 'regular attenders', only these subjects were included in the study. All the subjects in each area were examined by a single trained and calibrated examiner using a standardized technique. In 1994, a group of randomly selected dentists in each area completed a telephone questionnaire assessing attitudes and treatment patterns regarding fissure sealants. RESULTS: In 1989, 2836 letters were posted to parents asking for consent to examine their child and 2174 positive responses were received (response rate 77%). Of the 1919 children examined, 459 were classed as regular attenders, 140 in Doncaster, 159 in Hereford/Worcester and 160 in Wycombe. In 1994, 2560 consent letters were distributed to children in school to pass to their parents and 1587 positive responses were received (response rate 62%). Of the 1388 children examined, 891 were classed as regular attenders, 294 in Doncaster, 318 in Hereford/Worcester and 279 in Wycombe. Large rises in sealant prevalence were observed in all areas, but particularly in Doncaster where sealant prevalence increased from 13% in 1989 to 50% in 1994. In Hereford/Worcester it increased from 25% to 47% and in Wycombe it increased from 16% to 30%. There was also a fall in mean DMFT in all areas. In Doncaster it fell from 2.97 in 1989 to 1.82 in 1994, in Hereford/Worcester it fell from 2.60 to 1.83 and in Wycombe it fell from 1.86 to 1.29. In all three areas the changes in sealant prevalence and DMFT were statistically significant. The questionnaire revealed positive attitudes towards fissure sealants and their usage as well as a number of areas of concern that could potentially hinder sealant usage. CONCLUSIONS: Dramatic increases in sealant prevalence and considerable reductions in dental caries among these regularly attending adolescents have been demonstrated. Some concerns were highlighted regarding sealant usage, which may be prejudicing further increases in their application.

Apolipoprotein E and regulation of cytokine-induced cell adhesion molecule expression in endothelial cells.

Atherosclerotic plaques develop in the arterial wall from complex multicellular processes following the early recruitment of circulating monocytes. Infiltration of monocytes is mediated by cell adhesion molecules (CAMs), including vascular cell adhesion molecule-1 (VCAM-1) which is rapidly induced in endothelial cells in response to cytokines. Apolipoprotein E (apo E), a 34-kDa polypeptide, helps protect against atherosclerosis, in part, because apo E phospholipid particles secreted by macrophages may have local protective effects within lesions. Here we have investigated whether purified plasma apo E, complexed with dimyristoyl phosphatidylcholine (DMPC) vesicles, can inhibit cytokine-induced vascular cell adhesion molecule-1 (VCAM-1) expression in human umbilical vein endothelial cells (HUVECs). Expression of VCAM-1 in endothelial cells after exposure to tumour necrosis factor-alpha (TNF-alpha) or interleukin 1beta (IL-1beta) was quantified by ELISA and shown to be partially inhibited by 17beta-estradiol (40-60% inhibition) or by S-nitroso-L-glutathione, a nitric oxide donor (20-25%). However, preincubations with physiological concentrations (10-100 microg protein/ml) of apo E DMPC did not downregulate VCAM-1 expression, even with extended preincubation times. These findings were confirmed using a fluorescence-activated cell sorter (FACS) for analysis which indicated additionally that apo E-DMPC had no effect on sub-populations within the HUVEC cultures. Finally, apo E-DMPC vesicles were also unable to suppress TNF-alpha-induced upregulation of E-selectin or intercellular adhesion molecule-1 (ICAM-1). We conclude that plasma apo E is unlikely to be important in limiting endothelial activation.

Levels of restorative care under capitation.

OBJECTIVES: 1. To compare the prevalences of fissure sealants in similar groups of 14-15-year-old, regularly-attending patients treated under fee-for-service in 1989 and capitation in 1994. 2. To calculate the effect of including sealants in the restorative index on estimates of interventional treatment carried out on 14-15-year-old regularly attending patients treated by general dental practitioners in 1994. DESIGN: A randomised epidemiological study. SETTING: Secondary schools in the Wycombe, Doncaster and Hereford/Worcester areas. METHOD: Random samples of 14-15-year-old, regularly attending patients treated by dentists practising under capitation in three contrasting areas of England were examined in 1994 for the presence of decayed, missing and filled teeth and fissure sealants. Restorative indices were calculated with and without the inclusion of sealants. The latter were compared with restorative indices calculated without the inclusion of sealants on regularly attending patients of the same age group when the dentists in the same three areas were working under fee-for-service in 1989. RESULTS: The prevalence of fissure sealants increased between 1989 and 1994 from 16% to 30% in Wycombe, from 13% to 50% in Doncaster and from 25% to 47% in Hereford/Worcester. Without fissure sealants the restorative indices fell between 1989 and 1994 from a range of 76.5-94.4 to 63.3-87.1. When sealants were included in the restorative indices for 1994, they ranged from 79.5-92.9. CONCLUSIONS: There were increases in the prevalences of fissure sealants between 1989-1994. When these sealants were included in the calculation of restorative indices for 1994, the level of restorative care provided by general dental practitioners remained relatively high since the introduction of capitation. Although there has been some increase in the level of untreated disease, if the restorative index is calculated without the inclusion of sealants then there is a risk of underestimating the treatment provided by general dental practitioners to control the carious process. Dentists appear to be redirecting their efforts into newer treatment/preventive items.

An assessment of capitation in the General Dental Service contract 2. Patterns of treatment provided to regularly attending patients.

OBJECTIVE: To compare the patterns of treatment of general dental practitioners working under fee-for-service in 1987/88 with those working under capitation in 1992/93. DESIGN: 73 randomly selected general dental practitioners working under capitation in three contrasting areas in England retrospectively recorded the treatment provided during 1992/93 to a random selection of their regularly attending 6-12- and 14-15-year-old patients. RESULTS: Mean numbers of examinations per year reduced in the three areas from 1.7-1.8 in 1987/88 to 1.2-1.4 in 1992/93. Mean numbers of visits per patient dropped from 2.5-2.9 to 1.8-2.2. Mean numbers of fillings in permanent teeth reduced from 0.15-1.04 to 0.09-0.52 and in deciduous teeth from 0.28-0.53 to 0.24-0.31. Mean percentages of children per dentist having extractions fell from 9.3-28.1% to 4.7-16.2% while the radiographs reduced from 14.0-9.0% to 6.0-10.6%. Mean percentages of children per dentist receiving oral hygiene instruction rose from 18-31% in 1987/88 to 26-33% in 1992/93. Dietary advice increased from 3-18% to 11-20% and fissure sealants from 3-6% to 3-12%. CONCLUSIONS: In 1992/93, dentists working under capitation were carrying out fewer examinations, fillings and extractions and were taking fewer radiographs for their regularly attending child and adolescent patients than dentists working under fee-for-service in 1987/88. These patients also attended less frequently for treatment but received marginally more preventive care and advice.

An assessment of capitation in the General Dental Service Contract. 1. The level of caries and its treatment in regularly attending children and adolescents.

OBJECTIVE: To assess the dental health of regularly attending 7-8- and 14-15-year-olds registered under capitation in 1994. To compare the dental health of regularly attending 14-15-year-olds registered under capitation in 1994 with regularly attending patients of a similar age treated under fee-for-service in 1989. DESIGN: Random samples of 7-8- and 14-15-year-olds. Data were recorded on decayed and filled teeth, extracted for caries and teeth fissure sealed. RESULTS: Prevalence of caries in first permanent molars of 7-8-year-olds was 15-16%. Mean caries experience of deciduous posterior teeth was 1.78-2.51. 83-86% had no more than two untreated, decayed, posterior deciduous teeth. Prevalence of caries in 14-15-year-olds was 44-60% while mean caries experience was 1.29-1.83. Reductions in caries experience of 30-39% in 14-15-year-olds for 1989-1994 were due mainly to falls of 42-45% in mean numbers of teeth filled. Increases in mean numbers of decayed, untreated teeth were 0.07-0.11. The proportion of patients with teeth extracted because of caries was 2.4-3.8%. 30-50% had fissure sealants in 1994 compared with 13-25% in 1989. CONCLUSIONS: Dental health of regularly attending capitation patients is generally satisfactory with little evidence of 'supervised neglect'. Prevalence of fissure sealants has increased while the numbers of filled teeth has reduced. Numbers of decayed, untreated teeth have increased but the numbers of teeth extracted for caries have remained low.

Evidence for a paraoxonase-independent inhibition of low-density lipoprotein oxidation by high-density lipoprotein.

One mechanism by which plasma high-density lipoprotein (HDL) may protect against atherogenesis is by inhibiting the oxidation of low-density lipoprotein (LDL). Recent evidence suggests that paraoxonase, an HDL-associated, calcium-dependent enzyme, may be responsible for the antioxidant action of HDL (Mackness et al., Atherosclerosis 1993;104:129; Mackness et al., FEBS Lett 1991;286:152; Watson et al., J Clin Invest 1995;96:2882; Navab et al., Arterio Thromb Vasc Biol 1996;16:831); in particular, paraoxonase activity inhibits the formation of 'minimally oxidized' LDL by hydrolyzing biologically active oxidized phospholipids (Watson et al., J Clin Invest 1995;96:2882; Navab et al., Arterio Thromb Vasc Biol 1996;16:831). However, antioxidant effects of HDL have also been demonstrated under calcium-free conditions, arguing that this enzyme may not be the only mechanism by which HDL inhibits LDL oxidation (Tribble et al., J Lipid Res 1995;36:2580). Here we have evaluated the role of paraoxonase in prevention of LDL oxidation by using HDL subfractions, isolated from human serum or EDTA-plasma, which display markedly different levels of paraoxonase activity; the abilities of modified forms of HDL to prevent LDL oxidation by cultured human (THP-1) macrophages were also assessed. Paraoxonase activity was substantially lower in HDL prepared from plasma compared to serum HDL; moreover, virtually all of the lipoprotein-associated paraoxonase activity was located in the HDL3 fraction, with HDL2 retaining only 1-5% of the total activity. Despite possessing 5-fold differences in paraoxonase activity, HDL3 isolated from plasma or serum was equally effective in inhibiting LDL oxidation by THP-1 macrophages; furthermore, although plasma HDL3 was more protective than plasma HDL2, the latter did significantly inhibit LDL oxidation. Non-paraoxonase antioxidant constituents of plasma HDL3 were investigated further. ApoHDL3, the totally delipidated form of HDL3, was much less effective than native HDL3; when examined individually, purified apolipoprotein A-II gave greater protection than apo A-I, although this effect was not evident in apo A-II-enriched HDL3. Partial delipidation of HDL3, which removes both neutral lipids and alpha-tocopherol, did not significantly diminish its ability to inhibit LDL oxidation by THP-1 macrophages; phospholipid vesicles prepared from partially delipidated HDL3 also inhibited LDL oxidation effectively. We conclude that, in this model of cellular LDL oxidation, the phospholipid fraction of HDL exerts inhibitory effects which are independent of HDL paraoxonase activity.