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Biomedical subjects

K K Kapur

Publications and source records attributed to K K Kapur.

At least 37 records · Page 2Linked to original sources
PubMed1988

Requirements for clinical trials.

Significant progress and valuable contributions have been made by pioneers in the field of dental implantology during the past 20 years. The feasibility of clinical application of dental implants for specific prosthodontic conditions has been demonstrated by several reports based upon retrospective data or surveys of clinical experiences. However, there is a lack of reliable scientific information to determine the clinical efficacy of implant-supported prostheses or the physiological merits of the two types of implant-bone interface. Similarly, there are no known studies that have tested the relative efficacy of different implant systems. The claims of success rates for different implants can only be substantiated when controlled, independent studies are made, following research protocols that meet the requirements of clinical trials in terms of delineation of hypothesis, definition of treatment, entry and treatment allocations, exclusions and withdrawals, sample size, and a coordinated plan for the statistical analysis of data and interpretation of results. The study design of the VA Cooperative Study has followed the essential requirements of clinical trials in comparing the efficacies of the two treatment modalities--traditional removable partial dentures versus fixed partial dentures supported by implants.

Blade Implantation↗
PubMed1987

Veterans Administration Cooperative Dental Implant Study--comparisons between fixed partial dentures supported by blade-vent implants and removable partial dentures. Part I: Methodology and comparisons between treatment groups at baseline.

This study was conducted to determine whether fixed partial dentures supported by dental implants provide an acceptable alternative to conventional removable partial dentures in patients with Kennedy class I or class II edentulous conditions. The acceptability of the new treatment will be based on success rates, impact on the health of the remaining dentition, masticatory performance, patient satisfaction, and maintenance care and cost. The study was planned also to provide comparisons between two designs commonly used by dentists for fabricating removable partial dentures. The designs differed only in terms of the type of the retainer (clasp type) and tooth support (rest location). A total of 272 patients with Kennedy class I and class II edentulous conditions were assigned on a random basis to one of the treatment groups, 134 to receive a removable partial denture and 138 a fixed partial denture supported by a blade-vent implant. All of the patients were medically screened and met prespecified criteria for oral hygiene, bone support for abutment teeth, and size of the residual ridge. Thirty-four patients were eliminated from the study before completion of their treatment. An additional six patients with early implant failures were reentered in the study and followed up as a separate group. The remaining 232 patients received comprehensive dental care, including removable partial dentures for 118 and fixed partial dentures for 114 patients. A series of examinations, radiographs, masticatory performance tests, patient satisfaction, food selection questionnaires, and dietary history were completed before initiation of the treatment, 16 weeks after the insertion of an RPD or an implant, and thereafter at 6-, 18-, 36-, and 60-month intervals. In addition, patients were seen at 6-month intervals for a recall dental examination, oral prophylaxis, plaque instructions, radiographic survey of the implant, and any needed dental treatment. The randomization stratification approach produced two treatment groups with comparable age, number of remaining maxillary and mandibular teeth, type of opposing dentition, and percent of patients with Kennedy class I and class II edentulous conditions. The mean scores of bone support, tooth mobility, and sulcular depths of abutment teeth were also similar. Significant but comparable improvements in oral hygiene and sulcular depth occurred in the two groups after treatment. The periodontal health scores at the 16-week interval serve as the baseline to measure subsequent changes in periodontal health.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1986

Replicability of electromyographic recordings of the masseter muscle during mastication.

This study evaluates the reliability of a method to duplicate the location of surface electrodes for recording the electromyographic activity of masseter muscles during mastication and quantifying the activity by a microcomputer system. A plastic framework consisting of a bite fork and electrode positioners was used to place the electrodes by relating the positioners to an occlusal index and keeping this relationship constant at subsequent sittings. EMG recordings were repeated on two different days for each of 10 subjects while they performed standardized masticatory performance tests with peanuts and carrots. The muscle activity recorded with hardware integrators was an average of 26.7% of the computerized software integrations but measures derived from the two methods of integration were highly correlated (r = 0.965) and yielded similar results. Significant correlations were found between test sessions for each measure of masticatory performance and integrated EMG activity for ipsilateral and contralateral muscles. For each subject, no significant differences were found between sessions for any masticatory performance or EMG variable. The results indicate that reliable inter session EMG recordings during mastication can be made by using the template for positioning of the electrodes. In addition, the microcomputer data acquisition system provides results comparable to those obtained with conventional hardware integrators, with the added benefit of providing information on each individual stroke and its various components.

Adolescent↗
PubMed1986

Clinical efficacy of dental radiography in the detection of dental caries and periodontal diseases.

This article reports the ability of dental radiographs to correctly detect evidence of dental caries and periodontal disease (sensitivity) and to correctly establish the absence of these diseases (specificity). The analysis used a unique data set that was collected as part of the Veterans Administration Dental Longitudinal Study in Boston. Periapical, panoramic, and posterior bitewing radiographs were independently compared with a consensus radiographic standard of all three radiographs read simultaneously. Findings showed that the sensitivities of all three radiographs to detect dental caries were lower than expected, at approximately 60%, whereas the sensitivities to detect evidence of periodontal disease averaged approximately 85%. Panoramic radiographs were substantially less sensitive for detecting dental caries than periapical and posterior bitewing radiographs, but no difference between these modalities was observed in the analysis of sensitivity to periodontal disease. The proportion of false-negative and false-positive readings from dental radiographs was substantial and requires further investigation.

Adult↗
PubMed1985

Studies of biologic parameters for denture design. Part III: Effects of occlusal adjustment, base retention, and fit on masseter muscle activity and masticatory performance.

EMG recordings of ipsilateral and contralateral masseter muscles and standardized masticatory performance tests were made in 20 denture wearers before and after modifications were made to their clinically unsatisfactory dentures. The improvement of retention and stability by correction of gross occlusal prematurities and by the use of a denture adhesive or base reline with a soft tissue-conditioning material did not significantly alter the chewing performance or muscle activity during mastication in denture wearers. The results support our previous findings that the influence of denture factors on chewing ability of denture wearers is limited. To avoid variations in EMG activity caused by changes in electrode positions, all tests for a given subject were made at the same sitting. Thus the study design did not provide time to denture wearers for their neuromuscular mechanism to adapt to the modifications prior to testing masticatory function. A replication of this study that permits sufficient adaptation time after each modification is suggested to validate the findings.

Adhesives↗
PubMed1984

Studies of biologic parameters for denture design. Part II: Comparison of masseter muscle activity, masticatory performance, and salivary secretion rates between denture and natural dentition groups.

Bilateral masseter muscle activities exerted during masticatory and salivary secretion rate tests of a group of 18 denture wearers were compared with a group of eight persons with 26 or more natural teeth. Denture wearers applied 22% to 39% of the muscle force applied by the ND group to chew peanuts or carrots and showed markedly lower masticatory performances. The average muscle activity was higher for chewing peanuts than carrots in the ND group but was similar for both test foods in the AD group. Motor discrimination seems to be intact in denture wearers, but their inability to tolerate high masticatory pressures may prevent them from exerting discriminatory forces comparable to those applied by persons with natural dentition when chewing relatively tough foods of varying hardness. The results indicate that the reduced muscle force applied by denture wearers is another important factor that contributes to their diminished chewing ability. Even though the denture wearers were older and applied less muscle activity during chewing, they produced slightly higher rates of stimulated parotid saliva than the ND group. This supports our previous findings and further indicates that the mucosal stimulation of dentures compensates for decreased muscle activity and absence of periodontal receptor stimulation for producing saliva in healthy denture wearers.

Adult↗
PubMed1984

Masticatory performance and food acceptability in persons with removable partial dentures, full dentures and intact natural dentition.

This investigation indicated that measurable declines in masticatory function due to missing teeth, with and without prosthetic replacements, alter perceptual estimates of food acceptability. Using 1,133 male participants from the Veterans Administration Dental Longitudinal Study, individuals were classified into nine dentition categories to evaluate the effect of impaired masticatory ability. The data demonstrated that when limited declines in perceived masticatory function occur, perceptual estimates of Taste Acceptability, Texture Acceptability, and Ingestion Frequency for the 13 test foods utilized are not significantly modified. In contrast, when more severe dentition losses occur, the rheological properties of each food determine the degree to which these perceptual measures, especially Perceived Ease of Chewing, will be altered. Although restorative therapy can lead to concomitant improvements in masticatory function, low perceptual responses may still be observed. These appear to be largely a function of the physical attributes of the foods ingested.

Adult↗
PubMed1984

The effect of the loss of teeth on diet and nutrition.

Human food selection is dependent on a complex interaction of biological, environmental, cultural and behavioural influences. Numerous studies have provided evidence that food choice is guided neither by physiologic need nor item availability. The widespread prevalence of tooth loss seen in the elderly and the impact of impaired masticatory ability on food selection patterns is often overlooked. Available information suggests that declining masticatory function is, in a large part, responsible for the elderly consuming predominantly soft, easy to chew foods, which, in turn, can induce poor dietary practices and marginal nutritional intakes. It appears that with appreciable tooth loss there is a related decline in masticatory function; significant alterations also take place in certain perceptual and sensory measures. Generally, these perceptual changes reflect alterations in taste and texture preferences; phenomena which persist even after appropriate restorative dental therapy for missing teeth, with either removable partial or complete dentures. It has long been known that full denture wearers experience a reduction in flavour perception after the insertion of their prostheses. In the elderly the generalized decrease in ability to enjoy food has, in part, been attributed to flavour disturbances associated with their dentures. Whether the sensory loss is, to a large degree, due to the prostheses, or primarily reflects age-associated changes in the gustatory and olfactory receptors, is still being explored. The information presented suggests that persons with impaired dentitions , both with and without a dental prosthesis, may impose upon themselves certain dietary restrictions which, in time, can compromise their nutritional status and ultimately place them at health risk.

Adult↗
PubMed1982

Effects of age and dentition status on measures of food acceptability.

The current cross-sectional investigation was undertaken to determine whether observed losses in masticatory function due to missing teeth impair perceptual estimates of food acceptability. To quantify the effect of impaired masticatory ability, 566 male participants from the Veterans Administration Dental Longitudinal Study were subdivided into three age groups (less than 40 years, 40 to 49 years, and 50 or more years) and three dentition categories (intact, partially compromised, and compromised). Bivariate analysis revealed that dentition status significantly influenced the acceptance modalities of taste, texture, perceived ease of chewing, and frequency of ingestion. Age, per se, had little effect. Significant changes in the acceptance variables were noted only in persons with compromised dentition. These findings suggested that a moderate degree of unreplaced tooth loss had no significant effect on perceptual estimates of food acceptability, and unilateral intact dentition can provide sufficient masticatory performance for maintaining food acceptance.

Adult↗