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Biomedical subjects

K W Hemmings

Publications and source records attributed to K W Hemmings.

At least 19 recordsLinked to original sources
PubMed2001

Root resorption in retained deciduous canine and molar teeth without permanent successors in patients with severe hypodontia.

AIMS: The ability to predict the morbidity of retained deciduous teeth with no permanent successors, a characteristic of hypodontia, would be of considerable value in treatment planning, but is hampered by lack of data. METHODS: This problem was studied using 356 orthopantomogram radiographs (OPGs) from the records of 249 patients who had attended a specialist hypodontia clinic, and had retained deciduous teeth with no permanent successors. Due to their clinical importance, canine and molar teeth were chosen for examination. Resorption was assessed subjectively by three experienced clinicians. RESULTS: Un-weighted Kappa values for reproducibility were > 0.8, and for interobserver error 0.60-0.83. Gender related differences were minimal. Regardless of gender or radiographic age, the lower canines appear to show the least amount of resorption and the upper first molars the most. The upper and lower second molars have particularly unpredictable life spans. Whilst the lower first molars have a predictable life span that is poor, the life span for the upper first molars is slightly worse. CONCLUSIONS: Lower canines have a predictable life span that appears to be good, as do upper canines, but of lesser duration than lower canines. Molars have poorer and less predictable life spans.

Adolescent↗
PubMed2000

Tooth wear treated with direct composite restorations at an increased vertical dimension: results at 30 months.

STATEMENT OF PROBLEM: Severe tooth wear localized to the anterior maxillary or mandibular teeth with loss of interocclusal space is difficult to manage. PURPOSE: This study evaluated the outcome of composite restorations placed at an increased vertical dimension of occlusion in such patients. METHODS AND MATERIAL: Sixteen patients were restored with 104 restorations in 2 groups. In group A, Durafill composite and Scotchbond Multipurpose dentine adhesive system were used to place direct anterior restorations (N = 52). In group B, Herculite XRV composite and Optibond dentine bonding agent was used (N = 52). The restorations were placed at an increased vertical dimension of occlusion creating a posterior disclusion of 1 to 4 mm. RESULTS: Clinical follow-up showed that the posterior occlusion remained satisfactorily restored after a mean duration of 4.6 months (range 1 to 11 months). Mean follow-up of 30 months has shown a combined success rate of 89.4% for both groups with 93 of the restorations remaining in service. Maintenance in group A was high with 33 failures, but low in group B with 6 failures. Patient satisfaction was reported as good. CONCLUSION: Direct composite restorations may be a treatment option for localized anterior tooth wear.

Adult↗
PubMed2000

The provision of occlusal splints in primary dental care.

UNLABELLED: Occlusal splints (Michigan splints, night/bite guards or bite-raising appliances) can be an effective, inexpensive and reversible treatment for a wide range of dental problems. OBJECTIVE: The aim of this study was to analyse retrospectively the provision of occlusal splint ('Michigan' type) in general dental practice, following a prescription by a restorative dental consultant. METHOD: One hundred patients were recruited from consultant clinics in a department of conservative dentistry during 1995 and 1996. All patients were prescribed a maxillary, full-coverage, heat-cured, acrylic-resin splint (Michigan splint) as part of a treatment plan. An explanatory letter and questionnaire were sent to all patients and to their referring general dental practitioner in 1997 and 1998. RESULTS: A response rate of 79% was achieved in obtaining completed questionnaires from both patients and general dental practitioners. Of respondents 43% (34/79) received an occlusal splint of some form. A small proportion of the respondents (16.5% [13/79]) received a Michigan splint as prescribed. Irrespective of the type of appliance provided, most patients (82% [28/34]) found them helpful. Of those who did not receive an occlusal splint, 38% (17/45) of patients felt financial implications deterred them from obtaining an appliance. Other common reasons for non-provision included: patients felt that symptoms had improved (18% [8/45]) and patients did not agree with treatment (18% [8/45]). The general dental practitioners had similar opinions to their patients. DISCUSSION: These findings raise some serious doubts on the efficacy of consultant clinic advice in the prescription of occlusal splints in general dental practice. The financial and educational issues raised by this study will need to be addressed to improve service provision. CONCLUSION: The results of this study indicate that 16.5% of patient respondents prescribed a Michigan splint at a consultant clinic received such an appliance in general dental practice.

Comprehensive Dental Care↗
PubMed1999

Variations in planning fixed bridgework--a group of dentists at a case-based postgraduate course.

Variations in treatment planning and prescription have been described in relation to routine restorative dentistry. This study examined dentists' decisions regarding treatment planning for fixed bridgework. Fifty five dentists who attended a Continuing Education course on fixed bridgework were given standard information about a patient in the form of study casts, photographs of radiographs and a clinical history. They were asked to design a bridge where a previous one had failed and to complete a proforma which was returned to the course organisers in advance of the event. The response rate was 65%. The data showed wide variation in identification of features of diagnostic importance. Seventy percent of respondents chose to use again as abutments teeth which were extensively damaged and had failed to retain the previous bridge: while only 30% noted features of the occlusion which if left unchanged would have precluded a successful bridge from being made. A further feature was that nearly 70% chose to use multiple abutments to support the bridge. The implications of these results were discussed with respect to current concepts of bridge design.

Dental Abutments↗
PubMed1998

Case report: tooth wear associated with an unusual habit.

Pathological tooth wear is an increasing problem affecting a significant proportion of the population. Although different wear mechanisms have been described, most reports in the literature concentrate on cases in which the predominant mechanisms were erosion and attrition. This article presents an unusual case of abrasive tooth wear caused by a sand eating habit which the patient had adopted as a child. Different causes of "abrasive" wear are discussed and the difficulties in management of this case are also presented.

Adult↗
PubMed1997

Detection of neutral protease (Periocheck) and BANA hydrolase (Perioscan) compared with traditional clinical methods of diagnosis and monitoring of chronic inflammatory periodontal disease.

Perioscan requires a plaque sample to detect the presence of enzymes capable of degrading N-benzoyl-DL-arginine-2-naphthylamide (BANA) from relatively few anaerobic periodontal pathogens. Periocheck assays the presence of neutral proteases in crevicular fluid. The aim of this study was to compare these test kits with traditional clinical methods of detecting periodontal disease and to monitor the ability of the kits to reflect the response to initial therapy. 19 patients with moderately severe chronic periodontitis were seen before and after a course of oral hygiene and root instrumentation consisting of 4 appointments. Clinical measurements and test assays were collected at 5 diseased sites and 2 healthy sites in each subject. Complete data from 125 sites were available for statistical analysis. At baseline Periocheck had a sensitivity of 88% and a specificity of 61% whereas Perioscan had a sensitivity of 99% and a specificity of 55%, when related to the clinical diagnosis. A composite clinical assessment, based on improvement or deterioration of one whole unit change of the subjective clinical indices and 2 mm changes or greater in probing depth or probing attachment level, revealed 75 sites which improved following treatment, whereas 45 sites did not change and 5 sites deteriorated. The probability that the tests agreed with the clinical outcome after treatment, was calculated as 50.4% for Periocheck and 52% for Perioscan. The diagnostic kits did not reliably reflect the clinical assessment of periodontal disease in the cross sectional study, or the outcome following treatment.

Adult↗
PubMed1997

Psychosocial factors and tooth wear with a significant component of attrition.

Pathological tooth wear is often associated with bruxism, which appears in turn to be influenced by psychosocial factors. This study investigated putative relationships between psychosocial factors (total and average perceived stress, state and trait anxiety) and tooth wear, comparing 45 patients exhibiting tooth wear with a significant component of attrition to 45 controls. Groups were matched for gender and age. Subjects completed the Modified and Perceived Stress Scale and the State-Trait Anxiety Inventory. A between-groups multivariate analysis of variance indicated that the two groups did not differ significantly on the combined psychosocial factors, F(4,85) = 1.16, P > 0.05. However, a univariate F-test showed that tooth-wear patients presented significantly more trait anxiety than controls, F(1,88) = 4.15, P < 0.05. Further research is indicated to clarify the importance of trait anxiety and other psychosocial factors in the progression of tooth wear with a significant component of attrition.

Adult↗
PubMed1997

Treatment of localized anterior toothwear with composite restorations at an increased occlusal vertical dimension.

Patients may present with localized anterior toothwear, complaining of poor appearance or sensitivity, or both. Restoration of these teeth continues to cause problems, especially if interocclusal space has been lost. Conventional treatment to satisfy the patient's aesthetic and functional demands is time consuming and requires careful maintenance. This paper describes the use of chairside composite resin restorations in the treatment of localized anterior toothwear. Interoccusal space is provided by placing the restorations at an increased vertical dimension of occlusion. It enables the presenting complaint to be resolved while restoring structure, function and appearance.

Composite Resins↗
PubMed1996

Retrospective audit of patients with advanced toothwear restored with removable partial dentures.

The dental records of 50 patients with advanced tooth wear restored with removable prostheses were examined. Retrospective data were collected with regard to source of referral, presenting complaint, aetiological factors, clinical features, dentures provided, details of failures and maintenance. The maximum follow up period was three years. The ratio of male to female patients was 4:1 and the age range 31-75 years. Failures were recorded in 38% of patients with provisional and 64% with definitive dentures. The most common failure was fracture or wear of the incisal or occlusal surfaces. The majority of failures were addressed by adjustment of the dentures and the audit confirmed the need for regular maintenance.

Adult↗
PubMed1995

Partial dentures for patients with advanced tooth wear.

Many patients attend their dentist for advice, and often treatment, for tooth wear. Poor appearance and inadequate function are the most common presenting complaints but occasionally treatment is needed for acute or chronic pain or sensitivity. Although patients often prefer a fixed replacement for the missing tooth structure this is not always possible or appropriate. This article presents the practical aspects of managing patients with advanced tooth wear using removable partial dentures.

Dental Restoration Failure↗
PubMed1995

An immediate resin-bonded bridge using the natural tooth.

Missing anterior teeth are commonly replaced immediately with partial dentures, but this may cause embarrassing problems and a poor aesthetic appearance. This paper describes a technique for replacing anterior teeth using the natural tooth as a pontic with a resin-bonded cast metal framework. The main advantage of this technique is that a fixed restoration is provided on the same day as the tooth is removed, providing a major psychological benefit to the patient and maintaining the aesthetics. The short-term results are promising- and recent advances in adhesive dentistry mean that the long-term result should be equally as good.

Adult↗
PubMed1992

A survey of disease changes observed on dental panoramic tomographs taken of patients attending a periodontology clinic.

Dental panoramic tomographs (DPTs) were taken consecutively of 500 patients referred to a specialist periodontal department by general dental practitioners in order to assist in the diagnosis of the severity of the periodontal disease. Analysis of these DPTs showed 316 (63.2%) of these patients to have some form of dental abnormality unrelated to periodontal disease. The DPT was shown to be a valuable screening technique for clinical practice.

Adolescent↗
PubMed1991

Resistance to torsional forces of various post and core designs.

This in vitro study investigated the resistance of various post and core designs to torsional forces. Cast gold, parallel-sided, serrated post and cores were cemented in extracted teeth. The test groups were made up of the following designs: controls without an antirotational feature, keyway form, coronal flare form, auxiliary pin form, a cervical collar form, and included a tapered post group. The specimens were mounted on an Instron Universal testing machine and a torsional force was applied to the core using a lever arm until failure. All the antirotational features tested elevated resistance to torque. Failure occurred through fracture of the tooth, the cement, or an optional auxiliary pin. The cervical collar was the most favorable design, embracing resistance and reducing tooth fractures.

Dental Cavity Preparation↗
PubMed1990

A model for teaching periodontal surgery.

A simple laboratory-made model is described for periodontal surgical technique exercises. It has proved useful for tutor demonstration and student practice of all aspects of flap management.

Humans↗