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Biomedical subjects

U R Darbar

Publications and source records attributed to U R Darbar.

11 recordsLinked to original sources
PubMed1997

Particulate bioglass as a grafting material in the treatment of periodontal intrabony defects.

The present clinical trial was designed to evaluate the effects of a bioactive glass, Perioglas, in the treatment of periodontal intrabony defects. 20 patients, 23-55 years of age (44 sites), with intrabony defects completed the 1-year study. Teeth with furcation involvement were excluded. After completion of initial therapy, defects were randomly assigned to either a test or control procedure. Following flap reflection, root planing and removal of chronic inflammatory tissue in both groups, the test defects were restored with the bioactive glass particulate material. Mucoperiosteal flaps were replaced, sutured and a periodontal dressing was used. All the patients received postoperative antibiotics and analgesics and were seen at 1 week for suture removal. Follow-up was then carried out weekly and at 3 months, 6 months, 9 months and 1 year post-surgery. Plaque score, bleeding score, probing pocket depth (PPD), probing attachment level (PAL) and gingival recession were recorded at baseline, 3 months and 1 year. Standardised radiographs for computer-assisted densitometric image analysis (CADIA) were taken at baseline, immediately post-operatively and at 1 year. The CADIA data showed a significant increase (F-ratio: 15.67, p < 0.001) in radiographic density and volume between the defects treated with the Perioglas when compared to those treated with surgical debridement only. PPD and PAL showed significant improvements in both experimental and control sites, with a greater trend to improvement in the experimental sites. It was concluded that this bioactive glass is effective as an adjunct to conventional surgery in the treatment of intrabony defects.

Absorptiometry, Photon↗
PubMed1996

Combined treatment approach to gingival overgrowth due to drug therapy.

A case of severe gingival overgrowth associated with combined drug therapy of cyclosporin A and nifedipine is reported. The frequently increased vascularity of the gingival tissues in such cases often causes problems with bleeding both during and after surgery. Acrylic suckdown splints have been used postoperatively to assist haemostasis; however, these can interfere with function and cause discomfort. This report describes a combined treatment approach using conventional gingivectomy and carbon dioxide laser for the removal of the hypertrophic soft tissue. The benefits of such combined treatment include reduced bleeding during surgery with consequent reduced operating time and rapid post-operative haemostasis, thus eliminating the need for a splint.

Blood Loss, Surgical↗
PubMed1995

Finite element analysis of stress distribution at the tooth-denture base interface of acrylic resin teeth debonding from the denture base.

Acrylic resin teeth present a problem when they detach unexpectedly from the denture base resin. Detachment is caused by stress concentrations at the tooth/denture base resin interface. In this study, the finite element method was used to examine the stress distribution at this interface when a single static force that resembled incisal bite force was applied. The results indicated that irrespective of the type of acrylic resin teeth used, maximum tensile stresses were found at the palatal aspect of the interface. It is suggested that boxing the tooth in the acrylic resin will help redistribute stress concentrations favorably.

Acrylic Resins↗
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↗
PubMed1994

Denture fracture--a survey.

The fracture of dentures is an unresolved problem. Despite increasing costs incurred by the nation on the repair of these prostheses, very little has been documented on the type of fracture encountered. This survey was carried out to determine the prevalence of type of fracture by the distribution of questionnaires to three different laboratories. Results obtained showed that 33% of the repairs carried out were due to debonded/detached teeth. Twenty-nine per cent were repairs to midline fractures, more commonly seen in upper complete dentures. The remaining 38% were other types of fractures, the majority of which constituted repairs to upper partial dentures. The latter involved detachment of acrylic resin saddles from the metal in metal based dentures and the fractures of connectors in the all-acrylic resin partial dentures.

Acrylic Resins↗
PubMed1994

Stress analysis techniques in complete dentures.

The fracture of acrylic resin dentures remains an unresolved problem. It is known that eventual fracture of an appliance occurs due to crack initiation and propagation from areas of high stress concentration. In order to understand and overcome the problem of fracture, it is important to identify the regions of stress concentration. A number of different methods are used in stress analysis. However, the finite element method, a numerical technique, appears to overcome most of the problems associated with the earlier experimental methods. This article reviews the different techniques and their application to examining stresses in dentures.

Birefringence↗
PubMed1994

The effect of impurities on the stress distribution at the tooth/denture base resin interface.

The most common cause of teeth detaching from the denture base is the presence of impurities along the tooth denture-base interface. However detachment after a period of wear of the denture probably occurs due to the presence of stress concentrations along the interface from which cracks may initiate. The presence of the impurity will inevitably lower the stress threshold for cracks to propagate thereby increasing the risk of tooth detachment. Although this is obvious, there is no evidence to show the effect of impurities on the stress distribution at this interface. This pilot study utilised the finite element method to examine stresses at the tooth-denture base interface in the presence of simulated impurities interspersed along different positions on the interface. Within the limitations of the two-dimensional model used, it was concluded that the presence of an impurity at the edge of the palatal aspect of the interface has a significant effect on the stress magnitude. However, the presence of impurities elsewhere along the interface had no significant effect on the stress magnitude. This would have important implications during the processing of dentures.

Acrylic Resins↗
PubMed1993

Multiple external root resorption. Case report.

A case of a patient with multiple external root resorption affecting principally the molars and premolars is described. This case is unusual in that although both right and left molar and premolar teeth are involved, the resorption is worse on the left side and affects only the distal roots of the molars.

Adult↗
PubMed1993

The tooth-denture base bond: stress analysis using the finite element method.

Although acrylic resin teeth are the most popular artificial teeth used for denture construction, a high number fracture away at the tooth-denture base interface. Various causes have been documented for this failure; however, it is logical that eventual fracture occurs due to localised tensile stresses at this interface. Examination of these stresses using the finite element method showed that on load application to the upper incisors, the maximum tensile stresses were concentrated within the body of the tooth and not at the tooth-denture base interface. Stresses encountered at the interface were relatively low and introduction of a crack made no significant difference to their magnitude.

Acrylic Resins↗
PubMed1993

The periodontal abscess--a case report.

Determining the causative factors of dental abscesses continues to tax the diagnostic skills of clinicians. A case is discussed of an unusually presenting chronic periodontal abscess involving the bifurcation of the upper left first premolar.

Bicuspid↗