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Biomedical subjects

M V Martin

Publications and source records attributed to M V Martin.

At least 19 recordsLinked to original sources
PubMed2003

A study to assess the effects of a new detergent-free, olive oil formulation dentifrice in vitro and in vivo.

OBJECTIVE: To determine the effects of a detergent-free dentifrice containing olive oil using in vitro microbiological tests and an in vivo plaque re-growth model. METHOD: A total of 20 subjects took part in a double blind, single-centre, crossover study in which slurry rinses were the only form of plaque control over a 5-day period. Following a washout and prophylaxis the subjects used 2x daily rinses in the absence of all other plaque control methods. Subjects returned to the clinic on the afternoon of day 5 when plaque was disclosed and assessed by plaque index and area. A further 9-day washout was carried out and the rinse period repeated to ensure that each subject had used both experimental and control slurries. In vitro microbiological experiments were conducted to examine the effects of olive oil alone and in the new dentifrice on bacterial growth and adhesion. RESULTS: 20 subjects completed the trial. The olive oil product showed a significant inhibition of plaque re-growth (17.2%) compared with a fluoride-matched control using the Turesky index (p<0.0001) and also using the planimetric technique (22.0%) (p<0.0001). Significant decreases in bacterial growth and adhesion (measured as total viable count) were detected in the presence of olive oil and the new dentifrice. CONCLUSION: The results suggest that the experimental olive oil containing paste has potential value in the inhibition of plaque.

Adult↗
PubMed2003

Systemic antimicrobials in the treatment of chronic periodontal diseases: a dilemma.

The use of systemic antimicrobials in the treatment of acute and chronic periodontal diseases must be viewed as a dilemma. On the one hand, the approach is attractive because of the microbial nature of periodontal diseases but, on the other hand, evidence of benefit of these agents is equivocal for the majority of periodontal diseases and antimicrobials have the potential to cause harm. The disadvantages of systemic antimicrobials can be grouped under the headings of allergic reactions, superinfection, toxicity, drug interactions, patient compliance and, perhaps of most widespread importance, bacterial resistance. Mechanical debridement methods, including drainage of pus for acute periodontal abscesses, should be considered the first line treatment for most periodontal diseases. Systemic antimicrobials should be considered as adjuncts to mechanical debridement methods and, in chronic disease, never used alone as they can predispose to abscess formation. Adjunctive systemic antimicrobials may be considered in acute disease where debridement or drainage of pus is difficult, where there is local spread or systemic upset. In chronic periodontal diseases, adjunctive antimicrobials should be considered in early onset or rapidly progressive disease or in advanced chronic adult disease where mechanical therapies have failed or surgery is not a preferred option. Inadequate oral hygiene and tobacco smoking are contraindications to the use of antimicrobials. The value of systemic antimicrobials, where other systemic risk factors co-exist, has still to be established. The role of microbial diagnosis and sensitivity testing for antimicrobial selection at this time must be questioned.

Adult↗
PubMed2002

A survey of antibiotic prescribing by maxillofacial consultants for dental extractions following radiotherapy to the oral cavity.

OBJECTIVES: To analyse the antibiotic prescribing trends for exodontia and minor oral surgery in patients with a history of radiotherapy. Also, to evaluate the use of hyperbaric oxygen as a separate modality in the prevention of osteoradionecrosis. DESIGN: A survey of antibiotic prescribing involving the analysis of a questionnaire which included the management of three patients with a history of head and neck malignancy. METHOD: The heads of the departments in each unit in the UK were sent a closed-response questionnaire. Antibiotic prescribing was assessed in three case scenarios. Case one referred to a patient that had surgery alone as part of the management of head and neck cancer, who needed the surgical removal of second molar roots. Case two referred to a patient that had surgery and adjuvant radiotherapy as part of the management of head and neck cancer, and needed the same procedure as in case one. Case three included a patient with a history of surgery and adjuvant radiotherapy, who required the extraction of three mobile and periodontally-involved lower incisors. Consultants were also asked about the use of hyperbaric oxygen in the patients who had radiotherapy as part of their treatment strategy. RESULTS: A total of 109 questionnaires were sent to all the Maxillofacial Units in the UK. The response rate was 73%. In patients with a history of radical surgery alone for the management of head and neck cancer, 20% of the surgeons advocated pre-operative antibiotics for the surgical removal of lower posterior teeth. In contrast, in the patient with a history of adjuvant radiotherapy 86% supported pre-operative antimicrobial use for the surgical removal of the same teeth. In the extraction of mobile and periodontally involved lower incisors in the previously irradiated patient, 63% of the clinicians supported pre-extraction antibiotics. Postoperative antibiotics were advocated in 52% in the first case, 89% in the second case and 71% in the third case. 34% of the clinicians advocated hyperbaric oxygen for surgical removal of posterior teeth and 15% for the extraction of mobile anterior teeth. CONCLUSIONS: The use of peri-extraction antibiotics was favoured among oral and maxillofacial surgeons. There was little enthusiasm towards the use of hyperbaric oxygen as a prophylactic measure, alone or in conjunction with an antimicrobial regime. Control randomised trials that will measure the effectiveness of hyperbaric oxygen and the appropriate use of antibiotics for prophylaxis in pre- and post-operative regimes are necessary to evaluate the use of these modalities.

Antibiotic Prophylaxis↗
PubMed2002

A practical guide for patients undergoing exodontia following radiotherapy to the oral cavity.

Dental extractions or minor oral surgery in patients who have undergone radiation therapy for cancer in the head and neck carry the risk of one of the most serious and devastating complications of head and neck radiotherapy, that of osteoradionecrosis (ORN). A totally unified approach to dental extractions following radiotherapy is lacking. The role of the general dental practitioner in management of patients following radiotherapy is crucial. Contrary to clinical impression, the risk of ORN does not decrease with time. When contemplating exodontia or minor oral surgery in the irradiated patient, special consideration should be given to issues such as radiotherapy history, surgical assessment, surgical procedure and the role of antibiotics and hyperbaric oxygen.

Antibiotic Prophylaxis↗
PubMed2001

A preliminary investigation of the microbiology and endotoxin content in the water reservoirs of benchtop non-vacuum autoclaves.

UNLABELLED: To determine the microbial content and endotoxin concentration in the water reservoirs of benchtop autoclaves used in general dental practice. DESIGN: The study was done in two stages. Firstly water samples were taken daily from the reservoirs of 20 autoclaves used in general dental practices for six days. The microbial content and endotoxin concentration was determined. Second the practitioners were instructed to wash and clean the reservoirs of the autoclaves each morning prior to refilling with fresh water. The reservoirs were sampled in the evenings after a day's use and the microbial content and endotoxin concentration determined. RESULTS: The total viable count of bacteria before cleaning varied from 2,300 - 8 x 10(4) cfu/ml and after from 0-40 cfu/ml. The endotoxin concentrations before cleaning varied from 360-2,200 EU/ml and after 0-80 EU/ml. CONCLUSIONS: The reservoirs of non-vacuum benchtop autoclaves can become severely contaminated with micro-organisms particularly Gram-negative bacteria. The endotoxin content of the reservoirs can get to high and unacceptable concentrations. Draining the water reservoir and cleaning on a daily basis reduces the microbial content and the endotoxin concentration to acceptable levels.

Colony Count, Microbial↗
PubMed2001

Random mutagenesis of human cytochrome p450 2A6 and screening with indole oxidation products.

Cytochrome P450 (P450) 2A6 mutants from randomized libraries generated in the substrate recognition sequence (SRS) regions were screened in Escherichia coli on the basis of indole metabolism. SRS 3 and 4 libraries yielded colonies that produced indigo at least as well as wild-type (WT) P450 2A6, and some colonies were consistently more blue upon replating. One mutant, F209T, showed indole 3-hydroxylation WT. The double mutant L240C/N297Q consistently produced very blue colonies. Five mutants yielded mixtures of pigments from indole different than WT, as judged by visible spectra and HPLC of products. When bacteria expressing the mutants were grown in the presence of each of 26 substituted indoles, a variety of patterns of formation of different dyes was seen with several of the mutants. This approach has potential value in understanding P450 2A6 function and generating new dyestuffs and other products.

Aryl Hydrocarbon Hydroxylases↗
PubMed2001

Are antibiotics being used appropriately for emergency dental treatment?

AIM: To investigate the therapeutic prescribing of antibiotics to patients presenting for emergency dental treatment. DESIGN: A prospective clinical study. METHOD: Information was collected via a questionnaire concerning the patient's reason for attendance and treatment undertaken at emergency dental clinics in North and South Cheshire. RESULTS: Over an 11-week period 1,069 patients attended the five clinics, 1,011 questionnaires were analyzed. The majority of the attendees had pain (879/1011). 35% (311/879) of these patient had pulpitis and 74% (230/311) had been issued a prescription for antibiotics, without any active surgical intervention. Th principal antibiotic prescribed for both adult and child patients was amoxicillin. CONCLUSION: The majority of patients attending the emergency dental clinics had pain, with a large proportion having localised infections either as pulpitis or localised dental abscess. Three quarters of these patients had no surgical intervention and were inappropriately prescribed antibiotics.

Adolescent↗
PubMed2001

Can audit improve antibiotic prescribing in general dental practice?

OBJECTIVE: To investigate whether clinical audit can improve general dental practitioners' prescribing of antibiotics. DESIGN: An intervention study carried out in general dental practice in the North West of England. METHOD: Information was collected over an initial six-week period from 175 general dental practitioners on their current antibiotic prescribing practices. The information collected was the antibiotic prescribed including dose, frequency and duration, the clinically presenting signs and conditions, the medical history (if for prophylaxis), and any other reasons for prescribing. This was compared to the practitioners' antibiotic prescribing for a further six-week period following an audit, which included an educational component and the issuing of guidelines. RESULTS: During the initial period practitioners issued 2316 prescriptions for antibiotics. This was reduced by 42.5% to 1330 during the audit. The majority of the antibiotics (81%) for both periods were prescribed for therapeutic reasons. The most commonly prescribed antibiotics were amoxycillin (57.6%), metronidazole (23.8%), penicillin (9.3%), erythromycin (4.8%) and a combination of amoxycillin and metronidazole (1.7%). The antibiotic regimens used by practitioners were significantly changed by the audit (P<0.001) and there was a significant reduction in the number of prescriptions (P<0.05) which did not conform to national guidelines. CONCLUSIONS: The results from this investigation support the conclusion that clinical audit, with the issuing of guidelines and an educational component, can change prescribing practices leading to a more rational and appropriate use of antibiotics in general dental practice.

Anti-Bacterial Agents↗
PubMed2001

Stimulation of cytochrome P450 reactions by apo-cytochrome b5: evidence against transfer of heme from cytochrome P450 3A4 to apo-cytochrome b5 or heme oxygenase.

Many cytochrome P450 (P450)-dependent reactions have been shown to be stimulated by another microsomal protein, cytochrome b(5) (b(5)). Two major explanations are (i) direct electron transfer from b(5) and (ii) a conformational effect in the absence of electron transfer. Some P450s (e.g. 3A4, 2C9, 17A, and 4A7) are stimulated by either b(5) or b(5) devoid of heme (apo-b(5)), indicating a lack of electron transfer, whereas other P450s (e.g. 2E1) are stimulated by b(5) but not by apo-b(5). Recently, a proposal has been made by Guryev et al. (Biochemistry 40, 5018-5031, 2001) that the stimulation by apo-b(5) can be explained only by transfer of heme from P450 preparations to apo-b(5), enabling electron transfer. We have repeated earlier findings of stimulation of catalytic activity of testosterone 6beta-hydroxylation activities with four P450 preparations, in which nearly all of the heme was accounted for as P450. Spectral analysis of mixtures indicated that only approximately 5% of the heme can be transferred to apo-b(5), which cannot account for the observed stimulation. The presence of the heme scavenger apomyoglobin did not inhibit the stimulation of P450 3A4-dependent testosterone or nifedipine oxidation activity. Further evidence against the presence of loosely bound P450 3A4 heme was provided in experiments with apo-heme oxygenase, in which only 3% of the P450 heme was converted to biliverdin. Finally, b(5) supported NADH-b(5) reductase/P450 3A4-dependent testosterone 6beta-hydroxylation, but apo-b(5) did not. Thus, apo-b(5) can stimulate P450 3A4 reactions as well as b(5) in the absence of electron transfer, and heme transfer from P450 3A4 to apo-b(5) cannot be used to explain the catalytic stimulation.

Apoproteins↗
PubMed2001

Paediatric antibiotic prescribing by general dental practitioners in England.

OBJECTIVES: The inappropriate use of antibiotics is known to be a major contributory factor to the problem of antimicrobial resistance. No information is available on how practitioners prescribe antibiotics for children. This study investigated the prescribing of liquid-based antibiotics for children by general dental practitioners in England. DESIGN: Analysis of National Health Service liquid-based prescriptions issued by general dental practitioners in England. SAMPLE AND METHODS: All prescriptions issued by practitioners in 10 Health Authorities in England for February 1999 were collected. All the liquid-based antibiotic prescriptions for children were selected and we investigated the type of antibiotic prescribed, whether sugar free, the dose, frequency and duration. RESULTS: A total of 18,614 prescriptions were issued for antibiotics. Of the 1609 liquid-based paediatric prescriptions 88.3% were for generic and 11.7% for proprietary antibiotics, of which 75.5% were for amoxicillin, 15.2% for phenoxymethylpenicillin, 6.6% for erythromycin, 1.7% for metronidazole. Cephalexin, ampicillin, cephadrine and combinations of two antibiotics were also prescribed. There was a wide variation in dosages for all the antibiotics prescribed. A significant proportion of practitioners prescribed at frequencies inconsistent with manufacturers' recommendations and for prolonged periods, with some practitioners prescribing for periods up to 10 days. Only 29.1% of all the prescriptions issued were sugar free. CONCLUSIONS: The results of this study show that some practitioners prescribe liquid-based antibiotics inappropriately for children. This may contribute to the problem of antimicrobial resistance. Clear guidelines on the choice of antibiotic, dose, frequency and duration along with educational initiatives for GDPs might reverse this trend.

Anti-Bacterial Agents↗
PubMed2001

Antibiotic prescribing knowledge of National Health Service general dental practitioners in England and Scotland.

The inappropriate use of antibiotics has contributed to the worldwide problem of antimicrobial resistance. Information on the knowledge, understanding and training of dental practitioners in the use of antibiotics in clinical practice is scarce. This study assessed the level of knowledge of general dental practitioners and the need for educational initiatives. An anonymous postal questionnaire was sent to National Health Service dental practitioners working in 10 Health Authorities in England (1544) and four Health Boards in Scotland (672). Each correct answer to the questionnaire was given a score of one mark; there were 84 questions. The scores for each section of the questionnaire were compared. Responses were received from 1338 (60.4%) of practitioners, of whom 22.1% had attended postgraduate courses in the previous 2 years on antibiotic prescribing. Practitioners who had attended courses had a significantly greater knowledge of antibiotic use (P < 0.05) than those who had not. There was no significant difference in knowledge between all age groups under 60 years of age. There were significant differences in knowledge between dentists practising in English Health Authorities and Scottish Health Boards (P < 0.01). Knowledge was good for clinical signs that are indicators for prescribing antibiotics and for a number of non-clinical factors, e.g. patient expectation. Knowledge of therapeutic prescribing for commonly presenting clinical conditions and prophylactic prescribing for medically compromised patients, however, was generally poor. This study has shown that an urgent review of dental undergraduate and postgraduate education in antibiotic prescribing is required. Provision of prescribing guidelines may improve knowledge and encourage the appropriate use of antibiotics in clinical dental practice.

Anti-Bacterial Agents↗
PubMed2001

Murmurs, infective endocarditis and dentistry.

Patients with cardiac murmurs may have a predisposition to infective endocarditis, and the dental practitioner must be aware of this potential problem. This article reviews cardiac murmurs and how they are investigated by physicians to assess their significance. Practical advice is offered concerning the need to refer patients with a suspected heart murmur. The emergency and elective dental management of patients with heart murmurs is included, together with recommended regimens for antibiotic prophylaxis.

Adult↗
PubMed2000

Microbial aerosols in general dental practice.

OBJECTIVE: To measure the concentration of microbial aerosols in general dental practices and to use this information to carry out quantitative microbiological risk assessments. METHODOLOGY: Microbial air sampling was carried out continuously during 12 treatment sessions in 6 general dental practices in the South West of England. RESULTS: The microbial aerosol concentration in treatment rooms was generally less than 10(3) colony forming units per cubic metre of air (cfu x m(-3)). However, in 6 out of the 12 visits, at least one peak concentration with much higher numbers of bacteria was detected. The peak concentrations were associated with increased recoveries of presumptive oral streptococci suggesting these aerosols originated from the mouths of patients. These aerosol peaks dissipated within 30 minutes and no dissemination into waiting areas was detected. The peak concentrations were associated with mechanical scaling procedures (47% of procedures giving rise to a peak) and to a lesser extent by cavity preparation (11%). No aerosolised blood was detected. CONCLUSIONS: The data have been used to generate a framework for quantifying risk of exposure of staff to aerosolised microbial pathogens in general dental practice. For example, dentists and their assistants may have a slightly higher risk of exposure to Mycobacterium tuberculosis than the general public. The use of face seal masks that have been shown to protect against aerosolised micro-organisms may reduce this exposure.

Aerosols↗
PubMed2000

Infective endocarditis, dentistry and antibiotic prophylaxis; time for a rethink?

OBJECTIVE: To provide a critical review of the current evidence that links dental treatment to infective endocarditis (IE) and appraise the risks of antibiotic chemoprophylaxis. DESIGN: Retrospective analysis SETTING: Mainly hospital based patients or subjects OUTCOME MEASURES: The interrelationship between infective endocarditis and dental treatment is complex and in many instances uncertain. The risk from antibiotic chemoprophylaxis appear greater than the risk of contracting IE. RESULTS: There is increasing evidence that spontaneous bacteraemia are more likely to cause IE in at risk patients than specific episodes of dental treatment. Antibiotic chemoprophylaxis may not necessarily reduce dental-induced bacteraemia and the protective effect if any from antibiotic cover may arise from an inhibitory action upon bacterial colonisation on the compromised cardiac valves. CONCLUSION: There is increasing concern over the misuse of antibiotics in general and this has focused attention on chemoprophylaxis in dentistry to prevent IE. New evidence on dental-induced bacteraemia and the prevalence of IE in association with dental treatment raises further questions on the need to provide antibiotic cover in at risk patients. More prescriptive guidelines to define who is at risk from IE and what procedures require cover will help to reduce overprescribing of antibiotics and reduce the risks of their unwanted effects.

Anaphylaxis↗
PubMed2000

A study of prophylactic antibiotic prescribing in National Health Service general dental practice in England.

OBJECTIVE: To study the use of prophylactic antibiotics by general dental practitioners. DESIGN: A postal questionnaire of National Health Service (NHS) general dental practitioners in ten English Health Authorities. SUBJECTS: General dental practitioners (GDPs) (1544) contracted to provide NHS treatment in the Health Authorities of Liverpool, Wirral, Oxfordshire, Buckinghamshire, Nottingham, North Nottinghamshire, Sheffield, Newcastle, Northumberland and North Tyneside. MAIN OUTCOME MEASURES: The questionnaires were analysed and the responses to each question expressed as absolute frequencies. RESULTS: Responses to the questionnaires were received from 929 (60.1%) practitioners. Over 40% of general dental practitioners would prescribe prophylactic antibiotics for patients with no relevant medical history for minor oral surgery to prevent postoperative infection. Amoxicillin was the predominant choice of antibiotic in this situation. Between 15-67% of GDPs failed to prescribe prophylactic antibiotics for at risk medically compromised patients. GDPs also prescribed for patients with a medical history not known to be at risk from dental procedures. Over 50% of GDPs however, would seek specialist advice about prophylaxis if they were unsure of the indications and over 90% of GDPs indicated they would use the current recommended regime for antibiotic prophylaxis for patients at risk of infective endocarditis. CONCLUSIONS: The evidence from this study suggests that a significant number of the practitioners surveyed prescribe prophylactic antibiotics inappropriately, both for surgical procedures and for patients at risk from endocarditis. There is also evidence that practitioners prescribe antibiotic prophylaxis for clinical procedures and medical conditions for which there is little evidence. The results suggest that there is a need for the development of guidelines for practitioners on the appropriate prophylactic use of antibiotics.

Amoxicillin↗