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Biomedical subjects

N J Jepson

Publications and source records attributed to N J Jepson.

At least 19 recordsLinked to original sources
PubMed2006

Survival of resin-bonded bridgework provided for post-orthodontic hypodontia patients with missing maxillary lateral incisors.

OBJECTIVE: To analyse the clinical performance and factors influencing the survival of resin-bonded bridgework provided for hypodontia patients with missing maxillary lateral incisors, following orthodontic treatment to open, maintain or redistribute the missing tooth space. DESIGN: A retrospective analysis of patients treated at a single centre using case notes with all patients invited for review to corroborate findings. SETTING: Departments of Orthodontics, Child Dental Health and Restorative Dentistry, Newcastle upon Tyne Dental Hospital and School. SUBJECTS AND METHODS: Between 1989-2000, 59 suitable hypodontia patients were identified of whom 45 had complete records. For these patients 73 resin-bonded bridges (RBBs) were provided. Following invitation, 24 patients attended for a review appointment. The survival of the RBBs, grade of operator providing treatment, duration of post-orthodontic retention, the influence of design, presence of pontic contact in static and dynamic excursions, and the effect of habits were assessed. Life table, Kaplan-Meier and Cox regression analysis were carried out for the 73 RBBs with complete records. A separate analysis of the RBBs provided for patients who attended for the invited review did not show a higher failure rate than those patients who did not attend. Therefore both sets of data were combined. RESULTS: Of the 73 RBBs provided, 30 had debonded on at least one occasion (41.1%), six of these debonds were due to trauma (20%). The mean survival time of all the restorations was 59.3 months, with a median survival time of 59 months. Senior members of staff (Consultant, Senior Lecturer or Specialist Trainee) provided most restorations (n = 39) and achieved the highest mean survival of 72.6 months and median survival time of 100+ months. RBBs provided by junior staff and students had significantly lower survival times (p <0.05) compared with senior staff. Risk of failure was 3.9 times greater with junior staff and 2.5 times greater with students (p = 0.01 and p = 0.02, respectively). Analysis of all the other factors investigated showed no statistical difference in survival times or in hazard ratios. Analysis of fixed/fixed versus cantilevered bridges was limited by the number of fixed/fixed bridges (n = 11), and only two cantilevered bridges with multiple abutments were provided; both failed within one month. CONCLUSION: RBBs provided for post-orthodontic hypodontia patients with missing maxillary lateral incisors can for many patients be an acceptable and definitive restoration. Experienced staff achieved the best results, but why this should be was not explained by the individual factors analysed in this study.

Adolescent↗
PubMed2003

The interdisciplinary management of hypodontia: restorative dentistry.

This paper considers the role of restorative dentistry in the management of hypodontia. The paper describes the general restorative considerations common to patients with hypodontia and illustrates the variety of restorative techniques available in the restorative management of hypodontia and oligodontia.

Anodontia↗
PubMed2003

The interdisciplinary management of hypodontia: background and role of paediatric dentistry.

This paper is the first of a series on the comprehensive management of young people with hypodontia. The paper looks at the background to the condition, the possible aetiological factors, the prevalence of hypodontia and other related conditions. Lastly there is consideration of the role of the paediatric dentist in interdisciplinary management of the affected child and adolescent patient.

Adolescent↗
PubMed2001

Caries incidence following restoration of shortened lower dental arches in a randomized controlled trial.

CONTEXT: Removable partial dentures used to restore the shortened lower dental arch may adversely affect the remaining natural teeth and are associated with a low prevalence of use. OBJECTIVE: To report the findings for caries incidence 2 years after restoration of lower shortened arches with bilateral cantilever resin-bonded bridges (RBBs) and conventional partial dentures (RPDs). DESIGN: Randomised controlled trial. SETTING: Secondary care PATIENTS: 25 male and 35 female subjects of median age 67 years. were randomly allocated to 'bridge' and 'denture' treatment groups of 30 patients each matched for age and sex. Caries incidence was recorded during dental examinations 3 months, 1 and 2 years after insertion of new lower prostheses. INTERVENTIONS: Cantilever RBBs and conventional RPDs with cast metal frameworks. RESULTS: There was a highly significant difference in the frequency of new caries lesions, 11 and 51 in the bridge and denture groups respectively (P < 0.01). 20 out of 27 bridge patients and 9 of 23 denture patients had no caries experience. Multivariate modeling identified treatment group as the only significant predictor of caries occurrence. CONCLUSIONS: Two years after restoration of lower shortened arches for an elderly sample of patients, there was a significantly greater incidence of new and recurrent caries lesions in subjects restored with RPDs compared with cantilever RBBs.

Adult↗
PubMed2001

Evaluation of a computer-assisted learning programme on the oro-facial signs of child physical abuse (non-accidental injury) by general dental practitioners.

A computer-assisted learning programme with tutorials and self assessment multiple choice questions has been developed. One hundred and two general dental practitioners were asked to evaluate the programme. Over 80% of respondents felt that the programme was easy to use, contained an appropriate level of supporting information, and had improved their knowledge of non-accidental injury. All users of the programme felt that it was a better way of learning than video, audio tapes, and journals or books on the subject. It is concluded that CAL programmes are worthwhile for providing continuing professional education for general dental practitioners.

Adult↗
PubMed2001

Computing facilities available to final-year students at 3 UK dental schools in 1997/8: their use, and students' attitudes to information technology.

OBJECTIVE: To identify computer facilities available in 3 dental schools where 3 different approaches to the use of technology-based learning material have been adopted and assess dental students' perception of their own computer skills and their attitudes towards information technology. DESIGN: Multicentre cross sectional by questionnaire. SUBJECTS: All 181 dental students in their final year of study (1997-8). RESULTS: The overall participation rate was 80%. There were no differences between schools in the students' self assessment of their IT skills but only 1/3 regarded themselves as competent in basic skills and nearly 50% of students in all 3 schools felt that insufficient IT training had been provided to enable them to follow their course without difficulty. There were significant differences between schools in most of the other areas examined which reflect the different ways in which IT can be used to support the dental course. CONCLUSIONS: 1. Students value IT as an educational tool. 2. Their awareness of the relevance of a knowledge of information technology for their future careers remains generally low. 3. There is a need to provide effective instruction in IT skills for those dental students who do not acquire these during secondary education.

Attitude↗
PubMed2000

Influence of dietary simulating solvents on the viscoelasticity of temporary soft lining materials.

STATEMENT OF PROBLEM: Clinical changes in the viscoelasticity of temporary soft lining materials are characterized by a more rapid and increased reduction in compliance than is seen after in vitro immersion. A possible explanation for these differences is a solvent effect, acting clinically to encourage the loss of ethanol and plasticizer. Dietary solvents have been suggested as likely agents. PURPOSE: This study examined the effect of immersion in dietary simulating solvents on the viscoelasticity of temporary soft lining materials, with a view to formulating more clinically relevant immersion regimes used in the evaluation of these materials. MATERIAL AND METHODS: Four temporary soft lining materials were immersed in distilled water and solutions chosen to simulate dietary solvents. Changes in viscoelasticity over time were recorded with a penetrometer, modified to record creep strain and strain during recovery. RESULTS: All immersion solutions caused a significant reduction in compliance values of each material over time (P <.05). However, only heptane and corn oil immersants produced the rapid and increased reduction in compliance that is evident clinically. Changes in elastic recovery were less pronounced. CONCLUSION: Results of this study offer support to a dietary source of solvent acting to effect clinical changes in the viscoelasticity of temporary soft lining materials.

Analysis of Variance↗
PubMed2000

Nutrient intake in partially dentate patients: the effect of prosthetic rehabilitation.

OBJECTIVES: The objectives of this study were to investigate the impact of prosthetic rehabilitation of the shortened dental arch on the intake of nutrients, non-starch polysaccharide (NSP) fruits and vegetables (dietary fibre), and to compare dietary intakes between patients receiving bilateral resin-bonded bridges with patients receiving conventional partial dentures. METHODS: As part of an ongoing randomised clinical trial to compare the effectiveness of bilateral resin bonded bridges with conventional partial dentures, the diets of 40 partially dentate patients were assessed prior to and at 3 and 12 months following treatment with bilateral resin-bonded bridge-work or a lower partial denture. RESULTS: At baseline, three months post treatment and one year post treatment there were no significant differences in the intake of nutrients between groups. A significant increase in the percentage of energy from fat was observed in the patients fitted with a lower partial denture. Apart from this, prosthetic rehabilitation did not result in any other change in the intake of nutrients or in the amount of fruits and vegetables consumed. Levels of intake of NSP, fruits and vegetables were low in both groups of patients on all occasions measured. CONCLUSIONS: Prosthetic rehabilitation of the severely shortened dental arch does not result in dietary improvements. Dietary advice that takes into account all the factors that influence food choice (such as taste, cost and cooking skills) needs to be considered in this at risk group.

Aged↗
PubMed2000

Evaluation of a computer-assisted learning package on the management of traumatised incisors by general dental practitioners.

UNLABELLED: A computer-assisted learning program with a tutorial, self-assessment exercises and an expert system has been developed. Sixty-seven general dental practitioners were requested to evaluate the program. The results from those practitioners who returned the questionnaire showed that 57% found the program generally easy to use with the appropriate level of difficulty of tasks and content of supporting information, which it was felt improved their knowledge of the management of fractured incisors. CONCLUSION: It is worthwhile to develop such programs for the education of general dental practitioners. All users of this program felt that it was better than video, audio tapes, journals or books on the subject.

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

Achieving an even thickness in heat-polymerized permanent acrylic resin denture bases for complete dentures.

Permanent denture bases form the fitting surface of a denture and are constructed on a master cast, in heat-polymerized acrylic resin. These bases are strong and rigid and demonstrate both the fit and retention of the final prosthesis. General recommendations suggests a thickness of between 1.5 to 3 mm for these bases. The normal procedure for producing such a denture base is to manually adapt materials to the cast, in their plastic state, before processing. Such procedures are liable to distortion and variation in the thickness of the resultant denture base and may be unreliable. This article describes a method for achieving a consistent thickness in a heat-polymerized, permanent, acrylic resin denture base through the use of a vacuum-formed, thermoplastic blank as a template. The method is simple, and results in a denture base with a consistent even thickness.

Acrylic Resins↗
PubMed1998

A simple method for obtaining a uniform thickness for long-term soft denture linings.

The thickness of long-term soft denture linings influences both their compliance and durability. Increasing the thickness of the lining material increases its perceived softness but makes the restoration more likely to fail through weakening of the acrylic resin denture base. Such effects have led to broad recommendations as to an appropriate thickness, advice that assumes a constant thickness of the lining material within the same denture. Several procedures used to produce such a constant thickness have been described. The necessary spacer is produced by manually adapting materials in their plastic state to the cast. Such procedures are liable to distortion and variation in spacer thickness and can be considered unreliable. This article describes a method for obtaining a uniform thickness of soft denture lining through the use of a vacuum-formed, thermoplastic blank as a spacer. The method is simple, applicable to all ridge forms, and reliably results in a soft lining of a known, uniform thickness. The method can be applied to long-term soft linings placed in both old and newly fabricated dentures. The spacer can be modified to allow variations in the prescribed extension of the soft lining within the denture base.

Dental Prosthesis Design↗
PubMed1997

The determination of working time and gelation time of temporary soft lining materials.

OBJECTIVE: The purpose of this study was to establish a new method for the determination of working time and gelation time of temporary soft lining materials using a displacement rheometer. METHOD: A displacement rheometer (The Dental School, University of Newcastle, Newcastle upon Tyne, UK) was used to apply a rapid displacement of 0.25 mm held for 1 s at intervals of 60 s to samples of four temporary soft lining materials. Material displacement and elastic recovery at each test time was recorded. The test procedure was repeated three times at 23 degrees C and at 37 degrees C for each material. For one material, the displacement time was varied (1, 5, 10 s). The working time was defined as the time corresponding to the initial observation of elastic recovery at 23 degrees C. Gelation time was the time when a material achieved 95% of its maximum elastic recovery at 37 degrees C. Values were compared between materials using one-way analysis of variance and Student-Newman-Keuls test at the 5% level of significance. RESULTS: The gelation rate of all materials increased with increasing temperature although the extent of this influence varied between materials. The development of elastic recovery in the materials during gelation accurately fitted asymmetric sigmoids. The correlation coefficient (r) ranged from 0.982 to 0.999. Statistically significant variations in both the working and gelation times of the test materials were established. The time of displacement affected both the rate of development of elasticity and the value of elastic recovery but this effect was only statistically significant when the displacement time was increased to 10 s. SIGNIFICANCE: The displacement rheometer may be suited for use as a standard test method for the determination of the working time, gelation time and elastic behavior of temporary soft lining materials.

Acrylic Resins↗
PubMed1996

The influence of immersion solutions on the viscoelasticity of temporary soft lining materials.

OBJECTIVES: The purpose of this study was to examine the influence of laboratory immersion in a number of solvents on the viscoelasticity of temporary soft lining materials. It was an initial attempt to reproduce the changes seen clinically with a view to formulating more clinically relevant immersion regimes for the evaluation of these materials. METHODS: Changes in the viscoelasticity of four temporary soft lining materials following immersion at 37 + or - 1 degree C in 10% acetone/90% water, 20A% acetone/80% water and hexane was compared to a control immersion in distilled water using a penetrometer modified to record creep strain and strain during recovery. Testing was performed at 2 h and 24 h and then at 2, 4, 7, 21 and 28 d after sample preparation. Summary measures were used to describe individual specimen changes in derived values of initial and time dependent compliance and elastic recovery from 0-7, 7-28 and 0-28 d. RESULTS: Immersion in hexane resulted in at least a 50% reduction in compliance of 28 d. There was a significantly greater reduction in compliance for hexane immersion than for any other solvent (p<0.01). Immersion in 20% acetone resulted in an increase in compliance of around 1 mm/N after 1 wk compared with a reduction of up to 1 mm/N in distilled water. There was a reduction in elastic recovery for 3 out of 4 materials with 20% acetone/80% water solution. Changes in elastic recovery were smaller than those of compliance. SIGNIFICANCE: The reduction in compliance with hexane immersion suggests that this, or similar solvents, may form the basis of more clinically relevant immersion regimes. This may contribute to the development of improved temporary soft lining materials.

Acetone↗
PubMed1995

The influence of denture design on patient acceptance of partial dentures.

A study was designed to investigate the influence of denture design on patient acceptance of partial dentures. A total of 317 patients provided with partial dentures by the Department of Prosthodontics, Newcastle Dental School 2-3 years previously, were asked to complete a postal questionnaire about their use of these dentures. Denture status and partial denture design for these patients was established using hospital records. Design variables included material, the number and distribution of replaced teeth, denture support and connector design. In all, 86% of patients (273) returned the questionnaire. A total of 393 partial dentures (210 upper, 183 lower) had been constructed for these patients; 99 (25%) dentures were never worn and a further 57 (15%) dentures were only worn occasionally. Non-wearers were more likely to have no replacement anterior teeth, fewer replacement teeth and, in the lower, a lingual bar. When a multivariate model including all recorded variables was constructed using multiple logistic regression analysis, the presence of anterior replacement teeth for all dentures and the number of replacement teeth for upper dentures were found to be the only significant positive influences on denture wearing. Use of a lingual bar did not influence denture wearing habits.

Adult↗