Biomedical subjects

P F Allen

Publications and source records attributed to P F Allen.

At least 37 records · Page 2Linked to original sources

PubMed2001

An assessment of sensitivity to change of the Oral Health Impact Profile in a clinical trial.

UNLABELLED: Patient-based assessment of oral health outcomes is of growing interest. Measurement of change following clinical intervention is a key property of a health status measure. To date, most of the research on oral health status measurement has focused on construct and discriminant validity of health status measures. OBJECTIVES: The objective of this study was to assess sensitivity to change of an oral-specific health status measure, the Oral Health Impact Profile (OHIP). METHODS: Study subjects were in three groups, namely, edentulous/edentate subjects who requested and received complete implant stabilised oral prostheses (IG, n=26), edentulous/edentate subjects who requested implants but received conventional dentures (CDG1, n=22), and edentulous subjects who had new conventional complete dentures (CDG2, n=35). Data were collected pre- and post-operatively using the OHIP and a validated denture satisfaction questionnaire. RESULTS: All subjects reported similar low levels of denture satisfaction pre-operatively. Denture problems had a more significant impact on oral health-related quality of life (OHRQL) for implant seekers (IG and CDG1 subjects) than subjects seeking conventional dentures (CDG2). Following treatment, significant improvement in satisfaction with oral prostheses and OHRQL was reported by IG and CDG2 subjects; the level of improvement was more moderate for CDG1 subjects. OHIP change scores were correlated with denture satisfaction change scores. CONCLUSIONS: It was concluded that sensitivity to change of the OHIP was good. This property was not improved by using statement weights.

Analysis of Variance↗

PubMed2001

A patient-based assessment of implant-stabilized and conventional complete dentures.

STATEMENT OF PROBLEM: Outcomes of oral implant therapy have been described primarily in terms of implant survival rates and the durability of implant superstructures. Reports of patient-based outcomes of implant therapy have been sparse, and none of these studies have used oral-specific health status measures. PURPOSE: This study assessed the impact of implant-stabilized prostheses on the health status of complete denture wearers using patient-based, oral-specific health status measures. It also assessed the influence of preoperative expectations on outcome. MATERIAL AND METHODS: Three experimental groups requesting replacement of their conventional complete dentures completed an Oral Health Impact Profile (OHIP) and a validated denture satisfaction scale before treatment. One group received an implant-stabilized prosthesis (IG), and 2 groups received new conventional complete dentures (CDG1 and CDG2). After treatment, all subjects completed the health status measures again; preoperative data were compared with postoperative data. RESULTS: Before treatment, satisfaction with complete dentures was low in all 3 groups. Subjects requesting implants (IG and CDG1) had high expectations for implant-stabilized prostheses. Improvement in denture satisfaction and OHIP scores was reported by all 3 groups after treatment. Subjects who received their preferred treatment (IG and CDG2 subjects) reported a much greater improvement than CDG1 subjects. Preoperative expectation levels did not appear to influence satisfaction with the outcomes of implant therapy in IG subjects. CONCLUSION: Subjects who received implants (IG) that replaced conventional complete dentures reported significant improvement after treatment, as did subjects who requested conventional replacement dentures (CDG2). The OHIP appears useful in identifying patients likely to benefit from implant-stabilized prostheses.

Aged↗

PubMed2000

Peri-implant soft tissue maintenance in patients with craniofacial implant retained prostheses.

The aim of this pilot study was to describe the effectiveness of a hygiene protocol prescribed for patients receiving craniofacial implant retained prostheses. Eleven subjects receiving either orbital or auricular prostheses were instructed by a hygienist in debris removal procedures. Patients were re-examined on at least four occasions over the following 18 months, and tissue health around the implant abutments was evaluated using standard criteria. In most cases, adequate debris removal was demonstrated, particularly when hygiene procedures were reinforced at the second follow-up visit. Barriers to maintenance of tissue health included inadequate space between fixtures and thickness of skin around abutments. Occasionally, prostheses had to be replaced due to inappropriate cleaning methods. The intensive hygiene regimen helped maintain tissue health around implant abutments, although it was demanding in terms of professional time.

Adult↗

PubMed1999

Short and sticky options in the treatment of the partially dentate patient.

As we move into the twenty-first century, patterns of dental disease in adults are changing. Surveys of adult dental health indicate that more people are keeping their teeth for longer in life. In many cases, the ravages of dental disease and the cumulative effect of a lifetime of restorative dentistry lead to gradual tooth loss. For many of these patients, restoration of a complete dentition may not be feasible nor desirable. In recent years, functionally oriented treatment planning has become acceptable in light of recent research findings. Using this approach, treatment efforts and resources are directed principally at retaining the 'strategic' part of the dentition in the long term, ie, the anterior and premolar teeth. This paper describes, with the aid of treated cases, a means of combining a shortened dental arch strategy with resin bonded bridgework. With the aid of recent research in this area of clinical practice, some suggestions as to the use of the technique are also described.

Adult↗

PubMed1999

Measuring oral health: does your treatment really make a difference.

An understanding of a broader concept of health is increasingly important for all health professionals, including dentists, and has recently been incorporated as a key principle in the Government White Paper, The New NHS. This aims to deliver a dependable, high quality, egalitarian health service. In the past, performance measurements in the UK have often relied simply on those areas which are most easily quantified. For example, within the hospital service, performance was measured in terms of the cost and the number of finished consultant episodes, from which the 'purchaser efficiency index' was calculated. This tended to produce a driving force rewarding those doing more rather than those doing more better. It is analogous to the system which has been the backbone of NHS dental practice for many years, 'fee per item of service', where throughout is rewarded rather than outcome. However, the White Paper has signalled a move away from simply counting activity. From April 1999 within the hospital service the purchaser efficiency index has been replaced with more rounded measures, reflecting the changing concepts of health, in a new broader performance framework to determine what really counts for patients. It will focus on measuring health improvement, fairer access, better quality and outcome, including the views of patients.

Dental Care↗

PubMed1999

Patient expectations of oral implant-retained prostheses in a UK dental hospital.

STATEMENT OF PROBLEM: The loss of the natural dentition leads to severe functional impairment in many edentulous adults. A prosthesis retained and supported by osseointegrated dental implants may provide a satisfactory solution for people who have lost all their natural teeth. However, little information is available as to what patients requesting implants expect of implant-retained prostheses. AIM: The aim of this study was to assess the expectations of a group of edentulous patients requesting implant therapy. METHOD: The study included two groups: (1) a group of edentulous adults who requested implant therapy ('implant group'); and (2) an edentulous control group, of similar age and gender distribution as the implant group, receiving conventional complete dentures. Following a clinical and radiographic examination of the patients, data were collected using validated questionnaires. Both groups made a subjective assessment of current dentures. The implant group also completed a questionnaire which assessed expectations of implant-retained prostheses. RESULTS: Baseline satisfaction with current dentures was low in both groups, with the implant group being significantly less satisfied with comfort and stability of their mandibular dentures. Perceived ability of the implant group to chew hard foods was less than the control group. The implant group's expectations of an implant-retained prosthesis were significantly greater than for a conventional denture. CONCLUSION: Careful assessment of patient expectation of implant therapy is essential to determine appropriate treatment need, and to highlight unrealistic expectations.

Adult↗

PubMed1999

A comparison of the validity of generic- and disease-specific measures in the assessment of oral health-related quality of life.

UNLABELLED: In recent years, a number of instruments have been developed to measure the outcomes of oral disease. The Oral Health Impact Profile (OHIP) is the most sophisticated and comprehensive measure developed to date. At present, reports of the use of this measure are confined to descriptive population studies. OBJECTIVES: The aim of this study was to compare the validity of the OHIP with a generic health-related quality of life measure, the SF36. METHODS: Study subjects were in three groups, namely, edentulous patients seeking dental implants ("implant subjects", n = 32), edentulous patients seeking conventional dentures ("edentulous control", n = 35) and dentate patients ("dentate control", n = 21). All subjects completed an OHIP and SF36 prior to receiving any treatment. The edentulous subjects also completed a subjective assessment of satisfaction with their existing conventional dentures. OHIP data were computed using the simple count and weighted scores methods. RESULTS: The median number of negative impacts reported for each group was: 17 (implant subjects), six (conventional control) and one (dentate control). OHIP sub-scale scores were significantly higher (P < 0.001) for implant subjects than control subjects. There were no significant differences between the SF36 sub-scale scores. There was a significant correlation (P < or = 0.01) between aspects of satisfaction with conventional dentures worn by the edentulous subjects and OHIP sub-scale scores. Correlations between denture satisfaction variables and SF36 scores were not significant. CONCLUSIONS: It was concluded that the OHIP shows good discriminant and construct validity properties. As it is oral specific, it will be of greater use in measuring outcomes of oral disorders than generic measures such as SF36. This finding will be relevant when considering the use of health-related quality of life measures to target resources and measure the outcome of clinical intervention.

Adult↗

PubMed1999

The impact of tooth loss in a denture wearing population: an assessment using the Oral Health Impact Profile.

OBJECTIVES: To assess the impact of tooth loss in complete denture wearers using the Oral Health Impact Profile (OHIP), and to compare the validity of 49 and 14 item versions of OHIP in a denture wearing population. DESIGN: In this cross sectional study, data were collected at Newcastle Dental Hospital, UK. Two groups were involved: (1) subjects edentulous in one or both jaws seeking dental implants to retain their intra-oral prostheses (n = 48); (2) an edentulous control group of the same age and gender distribution requesting conventional, complete dentures (n = 35). All participants in the study completed a 49 item OHIP (OHIP-49) and a validated denture satisfaction questionnaire prior to active treatment. OHIP data were computed using the weighted standardised and simple count methods. Non-parametric statistical tests were used to compare the responses of implant and control subjects. RESULTS: Both groups were dissatisfied with their conventional dentures and had relatively similar levels of dissatisfaction. There were statistically significant differences between the groups for all seven OHIP-49 sub-scale scores. Differences between OHIP-14 sub-scale scores were also significant, with presence of teeth influencing the impact on psychological discomfort. CONCLUSION: Subjects in the implant group were significantly more impaired, disabled and handicapped by tooth loss than subjects seeking conventional dentures. The results suggested that OHIP-49 and OHIP-14 had a similar ability to discriminate between the groups. This indicates that OHIP-14 may be a useful aid in a clinical setting.

Adult↗

PubMed1998

A retrospective multicenter evaluation of single tooth implant experience at three centers in the United Kingdom.

STATEMENT OF PROBLEM: Implant treatment in the United Kingdom has been provided mainly in specialist, regional dental hospitals. However, increasingly, general dentists are providing implant-supported prostheses in a private office setting. PURPOSE: This study investigated the nature, timing, and frequency of complications associated with single tooth implant therapy in a dental hospital and two dental offices. METHODS: The dental records of 58 patients provided with 76 implants during the period of 1989-95 were reviewed retrospectively. Fifty-three single tooth crowns on implants were placed by general dentists and 23 by specialists in the dental hospital. RESULTS: Implant survival rate was 96%. Twenty-eight guided bone regeneration procedures were required, including 13 unplanned ones. Prosthodontic complications included the need for recontouring of three crowns and the recementation of three crowns. Only two abutment screws required retightening. Peri-implant soft tissue inflammation occurred around six crowns and recession around two. CONCLUSION: The single tooth implant-supported crown appears to be an effective and durable restorative treatment with a relatively low prevalence of postoperative complications.

Adolescent↗

PubMed1998

A survey of the attitudes of members of the European Prosthodontic Association towards the shortened dental arch concept.

A survey of members of the European Prosthodontic Association was undertaken to assess their attitudes to the shortened dental arch concept, and to evaluate their experience with the approach. Data were collected using questionnaires. From an overall response of 42%, 96% of respondents agreed that the approach was acceptable in clinical practice. Almost all respondents had applied the shortened dental arch concept with 72% of respondents having treated less than 50 patients in this way over the previous 5 years. In terms of comfort and function, treatment outcome was satisfactory. However, 42% of respondents indicated that prosthetic extension of shortened dental arches was occasionally required.

Attitude of Health Personnel↗

PubMed1997

Complications and maintenance requirements of implant-supported prostheses provided in a UK dental hospital.

AIM: To assess the nature, timing and frequency of complications associated with implant therapy and to assess maintenance requirements of implant-supported prostheses. DESIGN: Retrospective analysis. SETTING: The Dental Hospital in Newcastle upon Tyne. METHOD: Dental records of 60 patients provided with implant-supported prostheses were examined. Data were compiled on the number of fixtures placed per patient, the type of prosthesis provided, complications during the surgical and prosthodontic phases, and peri-implant soft tissue complications. RESULTS: 66 prostheses were placed on 236 fixtures over a 6-year period. Surgical complications included fixture loss (n = 6), dysaesthesia (n = 12), and the need for a guided tissue regeneration procedure (n = 10). Common maintenance requirements were tightening of components (n = 11), clip replacement (n = 7) and repair of conventional prostheses opposing implant supported prostheses (n = 7). Plaque control was unsatisfactory with almost half of the subjects requiring intensive oral hygiene instruction and scaling at the first post placement review. CONCLUSIONS: Prosthodontic maintenance requirements were high, particularly during the first year. Surgical complications were relatively infrequent. A case was made for a rigorous oral hygiene programme to reduce the potential for fixture loss through neglect. The financial cost associated with the maintenance of implant-supported prostheses should be incorporated in their overall funding.

Dental Clasps↗

PubMed1997

Dentists' attitudes to the shortened dental arch concept.

The aim of restorative dentistry in high-risk groups tends to shift over time from the preservation of complete dental arches towards the preservation of functional dental arches, using a functionally oriented approach. An example of this approach, aimed at limited treatment goals, is the shortened dental arch (SDA) concept. The objective of this study was to investigate dentists' attitudes to the SDA concept in general practice. A questionnaire seeking information pertaining to the attitudes and application of the SDA concept in clinical practice was sent to all dentally qualified members of staff in the field of restorative dentistry in the Nijmegen School of Dentistry (n = 64). From a 64% response, it was found that all but one of the respondents view the SDA concept as having a useful place in clinical practice. Although the respondents indicated only regular or occasional use of SDA in < 10% of patients, the outcome of SDA management was generally satisfactory or at least sufficient, notably in the care of special category patients. The findings support the view that the SDA concept has a role in contemporary clinical practice.

Attitude of Health Personnel↗

PubMed1997

Do item weights matter? An assessment using the oral health impact profile.

OBJECTIVE: To determine whether or not item weights contribute to the performance of the Oral Health Impact Profile (OHIP), a comprehensive measure of the functional, social and psychological outcomes of oral disorders. DESIGN: Data were obtained as part of an oral health survey of older adults living in Ontario, Canada. Subjects completed a personal interview, clinical examination and a self-complete version of the OHIP. OHIP scores were calculated in three ways: a simple count method, an additive method and a method incorporating item weights derived from the Thurstone paired comparison technique. These scores were calculated for the full 49-item version of the measure and for a short form consisting of 14 selected items. The discriminant, concurrent and predictive validity of these scores for the two versions of the measure were ascertained. PARTICIPANTS: Complete data were obtained for 522 subjects. Just over half were female (56 per cent) and their mean age was 66 years. RESULTS: The OHIP discriminated between groups based on dental status (dentate/edentulous), presence of dry mouth (yes/no) and, for the dentate, according to the number of remaining teeth (less than 20/20 or more) irrespective of scoring method or the version of the questionnaire used. All scores showed significant associations with self-rated oral health, self-perceived need for dental care and dissatisfaction with oral health status. There was evidence to suggest that weighted scores were better at discriminating between groups than the simple count method but no better than the additive method. Similar findings emerged with respect to the ability of the scores to predict prosthodontic, surgical and restorative treatment needs. CONCLUSIONS: Although the data suggested that item weights did improve the performance of the OHIP, the fact that simple scoring methods were as good as more sophisticated ones might mean that the OHIP could be used in contexts, such as patient assessment for clinical care, where the calculation of weighted scores was not feasible.

Aged↗

PubMed1996

Shortened dental arch therapy: views of consultants in restorative dentistry in the United Kingdom.

This paper reports the results of a study on the attitudes of the consultants in restorative dentistry (CRD) in the UK towards shortened dental arch therapy (SDAT). Data were collected by means of questionnaire, with a response of 67% achieved. The results indicate that 95% (n = 87) of the 91 participants in the study were of the opinion that SDA has a place in contemporary clinical practice. Eighty (88%) of the participants reported having prescribed SDA therapy during the last 5 years, the number of these patients requiring > 5 units of crown and bridgework being typically less than 25%. Forty-one (45%) of the participants reported patients being considered for SDAT expressing reservations about the outcome of their treatment, although around 75 (82%) of the participants indicated that SDAT was satisfactory in terms of oral function, comfort and well being. Experience of having to extend shortened dental arches following SDAT was limited to 34 (37%) of the participants. It is concluded that SDA is widely accepted but not widely practiced by CRDs in the UK and that, in patients satisfying existing criteria, the outcome of SDAT may be found to be acceptable in approximately 82% of cases.

Attitude of Health Personnel↗

PubMed1995

The role of the shortened dental arch concept in the management of reduced dentitions.

Current research indicates that a more biological approach to dental care is required to cope with current trends in adult health and to make more efficient use of ever dwindling public financial resources. This paper describes the role of the shortened dental arch concept (SDA) in the management of reduced dentitions, including criteria for its application, possible indications and contraindications, and presents a review of research supporting SDA. In light of recent research, it is suggested that SDA will be of increasing importance as a treatment philosophy for the future elderly.

Aged↗

PubMed1987

The effect of biotransformation of 2,4-dinitrotoluene on its mutagenic potential.

Because both oxidative and reductive metabolism of the hepatocarcinogen 2,4-dinitrotoluene (2,4-DNT) can occur in vivo, we have examined the mutagenicity of compounds which can be formed from 2,4-DNT in an attempt to establish which metabolic pathways contribute to the formation of genotoxic products. A quantitative reversion assay using Salmonella typhimurium TA98 was used to evaluate the mutagenicity of these compounds. 2,4-Dinitrobenzyl alcohol, 2-amino-4-nitrotoluene and 2-nitroso-4-nitrotoluene were found to be more mutagenic to S. typhimurium than is 2,4-DNT and did not require metabolic activation by post-mitochondrial supernatants of Aroclor-induced rat liver homogenates (S9) for their effect. 2-Amino-4-nitrobenzoic acid was also mutagenic to S. typhimurium TA98 in the absence of S9, but its mutagenicity was enhanced when S9 was included in the incubation mixture. 2,4-Diaminotoluene required S9 for demonstration of mutagenicity and was approximately as effective, on a molar basis, as 2,4-DNT in inducing reversion to histidine prototrophy. These results suggest that both oxidative and reductive metabolism may be involved in production of mutagenic metabolites of 2,4-DNT.

Animals↗

PubMed1984

The assessment of DNA damage and repair in rat nasal epithelial cells.

A methodology for the isolation and culture of rat nasal turbinates was developed with the aim of studying chemically-induced genotoxic effects in the nasal epithelium. DNA damage, as assessed by alkaline elution, and unscheduled DNA synthesis, as measured by quantitative autoradiography, were observed in the cells of the respiratory and olfactory epithelium as a result of in vitro treatment with methyl methanesulfonate. The capacity of nasal epithelium to metabolize the promutagen dimethylnitrosamine (DMN) was demonstrated by the induction of both DNA strand breakage and the induction of unscheduled DNA synthesis. Although a response was observed in all of the epithelia examined, differences in response to DMN were observed that were not attributable to the differences in the cell types present (e.g., respiratory versus olfactory epithelium). The respiratory epithelial cells of the maxilloturbinate were found to be resistant to the induction of DNA damage at concentrations of 0.5 and 1.0 mM DMN, whereas the respiratory epithelial cells of the nasoturbinates were susceptible. In contrast, the response of the olfactory epithelium was similar to the response observed in the cells of the nasoturbinates. These techniques should prove valuable in assessing chemically-induced DNA damage and repair in this target tissue.

Animals↗

PubMed1981

The mutagenicity of dinitrotoluenes in Salmonella typhimurium.

The mutagenicity of technical grade 2,4-dinitrotoluene (DNT), a mixture composed predominantly of 2,4-DNT (76.5%) and 2,6-DNT (18.8%) but containing 3,4-, 2,3-, 2,5- and 3,5-DNT, and the 6 isomers of DNT has been determined in 3 assays with Salmonella typhimurium. The mixture and the individual isomers of DNT were found to be mutagenic in the Ames' Salmonella/microsome test, particularly in strains responding to frame-shift mutagens; 3,5-DNT was found to be the most effective isomer in inducing reversion to histidine prototrophy in S. typhimurium strains TA98 and TA1538. Similar results were obtained with a quantitative reversion assay using strain TA98; 3,5-DNT was the most mutagenic of the compounds examined, particularly in the absence of post-mitochondrial supernants of rat-liver homogenates. While all isomers and the mixture of DNTs increased the 8-azaguanine-resistant fraction of S. typhimurium TM677 to some degree, the greater mutagenicity of 3,5-DNT compared to other isomers was not evident in the forward mutational assay.

Animals↗