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A Fenton

Publications and source records attributed to A Fenton.

32 records · Page 2Linked to original sources

Titanium for prosthodontic applications: a review of the literature.

Titanium has become a material of great interest in prosthodontics in recent years. A growing trend involves the use of titanium as an economical and biocompatible replacement for existing alloys for fixed and removable prostheses. However, long-term results of titanium casting, joining, and porcelain bonding have to be evaluated before this wonder metal can be used routinely in clinical dentistry. This article describes the development and properties of titanium and reviews the literature related to the use of titanium in prosthodontics, for the purpose of evaluating the present status and future trends in its use.

Chromium Alloys↗

The Scottish tonsillectomy audit. The Audit Sub-Committee of the Scottish Otolaryngological Society.

Regional specialist societies offer a valuable mechanism for the conduct of medical audit. The experience of the audit sub-committee of The Scottish Otolaryngological Society in conducting an audit on laryngeal cancer encouraged us to undertake a larger audit of tonsillectomy practice in Scotland. Although the number of tonsillectomies performed has declined over the last 10 years, they still account for about 20 per cent of all operations performed by otolaryngologists and as such are a major consumer of resources (Personal communication-Directorate of Information Services, Information and Statistics Division. NHS in Scotland, Management Executive, Edinburgh). The Scottish tonsillectomy audit was devised to define current practice, review indications for surgery and recommend such modifications in practice as may be necessary to optimise patient care and the use of resources. Funding was obtained from the Clinical Resource and Audit Group (CRAG) of the Scottish Home and Health Department. Data on current practice was collected during the period February 1992 to January 1993. Proformas were completed by medical, administrative and secretarial staff in all participating hospitals, collected by an audit secretary and passed to the relevant data collection centre. Data was then entered into a specially designed database before being forwarded to the audit co-ordinator based in Dundee for collation. Six and 12 months following surgery, all inpatients were sent a questionnaire to obtain data on the efficacy of the operation. Data were obtained from a total of 9,773 patients. Two thousand and seventy-nine of these were seen as both outpatients and inpatients, 4,309 were outpatients only and 3,385 were inpatients only. Four thousand, one hundred and one patients returned at least one follow-up questionnaire. The topics audited included source and reason for referral, indications for surgery, grade of staff involved, type of surgery and length of stay in hospital. In agreement with previous studies (H.M.S.O., 1989), differences were found in the rates of tonsillectomy performed in different Health Boards. Although the highest referral and operation rates were found in the Highland region, referral and operation rates did not correlate in all other areas. Recurrent tonsillitis was the most frequent principal reason for the decision to operate although there were differences between Health Boards for other indications including obstructive symptoms. Most patients had symptoms for two to three years although some patients had been affected for 40 years prior to being listed for tonsillectomy. Some are ENT services were consultant-based while others involved more junior staff. The grade of staff involved did not appear to affect the decision made at the Outpatient Department (OPD) or the outcome of the operation. Ninety-eight per cent of patients who returned the questionnaire were glad that the operation had been performed. Recommendations regarding changes in tonsillectomy practice are given.

Adolescent↗

Neonatal intensive care cots: estimating the population based requirement in Trent, UK.

STUDY OBJECTIVES: To estimate the population based requirement for neonatal intensive care (NIC) cots by investigating NIC utilisation in a large population based study. DESIGN AND SETTING: This was a two year, non-randomised, prospective cohort study of neonates receiving NIC in hospitals in the Trent Regional Health Authority (RHA). PARTICIPANTS: The main study considered the 2979 neonates born to Trent RHA residents who had begun high dependency care in Trent RHA or neighbouring health authorities between 1 April 1990 and 31 March 1992 and met any of the following criteria: (i) birth weight < 1500 g; (ii) gestation < 32 weeks; (iii) need for active respiratory support other than initial resuscitation; (iv) need for in utero or neonatal transfer to receive high dependency care; (v) severe asphyxial brain insult after delivery : and (vi) death. The analysis here is restricted to the 1730 neonates who received total parenteral nutrition or assisted ventilation, or both; that is, those who received NIC level 1 (ICL1) on at least one day. MEASUREMENT AND ANALYSIS: The treatment history of each neonate was converted into a time-line detailing the dates of beginning and stopping NIC, the dates of any transfers between units, and any gaps in NIC treatment. The duration of ICL1 was observed directly and that of intensive care level 2 (ICL20 was imputed from a model based upon round trip transfers. These were also recorded on the timeline. The time-lines were first used to derived the observed distribution of the utilisation of NIC cots in Trent RHA during the study. An extensive series of Monte Carlo simulations was then carried out in order; (i) to estimate cot requirements in smaller populations; (ii) to determine whether Trent RHA utilised its NIC cots in a manner that was clinically appropriate at the population based level; (iii) to perform a series of sensitivity analyses; and (iv) to compare results with an equivalent study carried out in the Northern RHA. MAIN RESULTS AND CONCLUSIONS: Trent RHA is reasonably representative of the greater population of England and Wales in terms of both the distribution of birth weight and of birth weight-specific neonatal mortality. Trent RHA did not seen to be underprovided for NIC cots or to be overusing these cots inappropriately. It therefore seems reasonable, if the assumptions of the analysis are borne carefully in mind, to treat these utilisation data as a rough guide to true population based need. NIC cot requirements depend critically upon the size of the served population - small populations are subject to greater random variability and require relatively more cots to ensure cot availability on an equivalent proportion of days. A neonatal unit should not therefore serve a population generating fewer than 5000 and 25 000 births per annum, the estimated population based provision which would ensure free cots on 29 out of 30 days falls gradually from 1.20 to 0.88 NIC cots per 1000 births per annum. A cooperative network of NICUs offers the opportunity to provide fewer cots per head of population while maintaining good access for most neonates referred to the service.

Bed Occupancy↗

The role of dental implants in the future.

Osseointegration's documented success allowing bone and mucosal tissue to tolerate a titanium implant has dramatically expanded the possibilities of dental care. We can now replace extracted teeth. Maintaining implants is different, but simpler than tooth maintenance. There is much interest in quicker procedures, shorter healing times or other materials to see if they can be as successful as CP titanium. Some may prove to be so. In any case, osseointegration has had as much impact on 20th century dentistry as local anesthetics, fluorides and the air rotor. Our practices and curricula, are changing to remain contemporary and ready for the 21st century.

Aluminum Oxide↗

Comparative accuracy of implant impression procedures.

In this study, four impression procedures were assessed for accuracy in a laboratory model that simulated clinical practice. The accuracy of stone casts with brass implant analogs was measured against a standard framework. The fit of the framework on the casts was tested by manual and visual judgment and by microscopic measurement. The measurements supported the clinical judgments. When acrylic resin was used to splint transfer copings in an impression, all casts were acceptable and were more accurate than the best of the two other procedures, which did not use an acrylic resin splint. When an impression material was used to orient the transfer copings, the accuracy was better if undercut copings remained in the impression. When impressions were made by removing an impression from smooth transfer copings and replacing the copings in the impression, the majority of casts were unacceptable.

Analysis of Variance↗

A monoclonal antibody capture ELISA to detect antibody to border disease virus in sheep serum.

An enzyme-linked immunosorbent assay (ELISA) has been developed to detect antibody to border disease virus (BDV) in sheep serum. A monoclonal antibody bound to 96-well microplates was used to capture antigen from detergent-solubilised BDV-infected cells. Single dilutions of test sera were then added to wells containing bound BDV antigen and control wells containing uninfected cell lysates. Specific antibody to BDV was detected by an anti-ovine IgG antiserum conjugated with horseradish peroxidase and the results expressed as ELISA units with reference to a standard curve. Sequential sera from 16 experimentally infected sheep and single sera from 103 sheep involved in a field outbreak were tested in the ELISA and for neutralising antibody. There was good qualitative correlation between the two tests.

Animals↗

Identification of cattle infected with bovine virus diarrhoea virus using a monoclonal antibody capture ELISA.

A monoclonal antibody capture enzyme linked immunosorbent assay (ELISA) has been developed to detect pestivirus-specific antigen in the leucocytes of cattle infected with bovine virus diarrhoea virus (BVDV). A blind trial was conducted to compare the specificity of the ELISA with conventional tissue culture virus isolation on 215 blood samples submitted for BVDV diagnosis from cattle throughout Scotland. One hundred and sixty seven samples were negative by both ELISA and virus isolation and 47 samples were positive by both tests. One blood was negative by ELISA and positive by virus isolation.

Animals↗

An ELISA for detecting pestivirus antigen in the blood of sheep persistently infected with border disease virus.

A monoclonal antibody capture enzyme-linked immunosorbent assay (ELISA) has been developed to detect a pestivirus-specific antigen in leucocytes of sheep persistently infected with border disease virus. A blind trial was conducted to compare the specificity of the ELISA with conventional tissue culture virus isolation on blood samples from 58 sheep, aged 3 to 48 months. There was total agreement between the two tests; 27 sheep were shown to be BDV-infected. The ELISA OD values of the positive samples ranged from 0.12 to 0.86 and were not related to age, strain of virus with which they were infected or presence of serum neutralising antibody. Negative samples had OD values between 0 and 0.02.

Animals↗

Prognostic indicators in tibial shaft fractures: serum creatinine kinase activity.

Serum creatinine phosphokinase (CPK) levels were measured serially in 50 adults with closed tibial shaft fractures. CPK activity increased significantly after fracture (p less than 0.001). High energy and slowly healing fractures had significantly higher levels than low energy and normally healing fractures, respectively. Thus, CPK determinations could be used to assess the severity of trauma and possibly prognosis in tibial shaft fractures.

Adolescent↗