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Biomedical subjects

K K Kapur

Publications and source records attributed to K K Kapur.

At least 19 recordsLinked to original sources
PubMed1998

A randomized clinical trial comparing the efficacy of mandibular implant-supported overdentures and conventional dentures in diabetic patients. Part II. Comparisons of masticatory performance.

STATEMENT OF PROBLEM: Convincing evidence is lacking to demonstrate the functional superiority of mandibular implant-supported overdentures over conventional dentures. PURPOSE: This randomized clinical trial was conducted to compare masticatory functional effectiveness of mandibular implant-supported overdentures and conventional dentures in diabetic denture wearers with clinically acceptable metabolic control. METHODS: A total of 102 edentulous diabetic patients, treated with or without insulin, were randomized to receive a new maxillary and either a mandibular conventional denture or an implant-supported overdenture. Treatment was completed in 89 patients, 37 with conventional dentures and 52 with Hader bar-clip attachment overdentures supported by two IMZ implants. Besides data from medical and dental histories, oromaxillofacial examinations, and questionnaires, masticatory tests were performed by patients before and at 6 and 24 months after treatment completion. Although 78 patients (28 in the conventional, 50 in the overdenture group) performed tests at 6 months after treatment, 68 (25 in the conventional, 43 in the overdenture) had performance data for both entry and 6-month posttreatment intervals. RESULTS: The two treatment groups were highly comparable in terms of general characteristics, quality of original dentures, tissue support, and past denture experience. No significant differences were found between patients treated for diabetes with or without insulin. All four masticatory performance scores with original dentures were higher in the conventional denture group than the overdenture group. The posttreatment performance scores for the two treatment groups became similar because of the higher gains in the overdenture group. Patients with low initial performance scores showed greater posttreatment gains with both conventional dentures and overdentures. CONCLUSIONS: The implant-supported overdenture showed no significant advantage over the conventional denture for improving the ability to comminute food in this group of diabetic patients with higher than average initial functional levels observed for other groups of denture wearers in previous studies.

Analysis of Variance↗
PubMed1998

A randomized clinical trial comparing the efficacy of mandibular implant-supported overdentures and conventional dentures in diabetic patients. Part I: Methodology and clinical outcomes.

STATEMENT OF PROBLEM: Scientific evidence is lacking to support the general application of implant-supported mandibular overdentures. PURPOSE: This randomized clinical trial was undertaken to compare the efficacy of conventional mandibular and implant-supported overdentures in diabetic edentulous patients with clinically acceptable metabolic control. METHOD: A total of 102 diabetic patients, treated with or without insulin, were randomized to receive a new maxillary denture and either a conventional or an implant-supported removable mandibular overdenture. Treatment was completed for 89 patients, 37 with the conventional and 52 with implant-supported dentures. Detailed examinations, tests, and questionnaires were given before and at 6- and 24-months after treatment completion. Comparisons between the two treatment groups were made for treatment failures based on prespecifed criteria and the type and amount of maintenance care provided. RESULTS: The insulin and noninsulin treated groups were collapsed because of the lack of significant differences at entry. The conventional denture and implant-supported overdenture groups were similar in terms of general demographics, medical status, quality of their original dentures and denture support, several functional measures, and patient satisfaction. Treatment was judged to be successful in 56.9% of patients with conventional dentures and 72.1% with overdentures. This difference in success rate was not statistically significant (p > 0.05). Patients with treatment failures in both groups required excessive maintenance care. Those with conventional dentures needed frequent denture base adjustments and relines, whereas those with overdentures required frequent clip replacements and repairs. Although significant improvements were seen with both treatment modalities, a higher percentage of patients with implant-supported overdentures than those with conventional dentures reported improvements in chewing comfort and moderate-to-complete overall satisfaction.

Alveolar Bone Loss↗
PubMed1997

A randomized clinical trial of two basic removable partial denture designs. Part II: Comparisons of masticatory scores.

STATEMENT OF PROBLEM: There is no known data on the functional efficacy of different removable partial denture designs. PURPOSE: This randomized clinical trial compared the masticatory performance of two commonly used designs in 118 patients who needed a unilateral or bilateral mandibular partial denture. MATERIAL AND METHODS: One half of the patients received a partial denture with distal occlusal rests and cast circumferential clasps and the other half a partial denture with mesial rests and I-bar cast clasps. The left side, right side, and swallowing threshold masticatory tests were made with peanuts and carrots before treatment and 16 weeks after the prosthesis insertion (baseline) and thereafter at 6, 18, 36, and 60 months. RESULTS: Masticatory scores at entry were higher in the circumferential design group, but the only significant (p < 0.05) difference was found in the right side carrot performance. Both groups realized significant improvements (p < 0.001) in all performance scores with partial dentures. Mean improvements of 24.7 with peanuts and 35.8 with carrots in the right side performance scores and 19.0 in the swallowing threshold score with peanuts in the bar design group were significantly higher (p = 0.017) than the respective mean improvements of 15.9, 21.4, and 5.6 in the circumferential design group. However, no significant differences were found between the two groups for any of the 10 performance scores at baseline. CONCLUSIONS: Despite some performance differences at entry, the mean performance scores for the two groups became similar at baseline and at subsequent intervals.

Arachis↗
PubMed1997

Veterans Administration Cooperative Dental Implant Study--comparisons between fixed partial dentures supported by blade-vent implants and removable partial dentures. Part V: Comparisons of pretreatment and posttreatment dietary intakes.

PROBLEM: Good scientific evidence is lacking on the impact of improvement in masticatory function after prosthodontic restoration of missing teeth. PURPOSE: This study compares 1-week dietary intakes of 218 healthy, male patients, 111 patients restored with mandibular unilateral or bilateral distal base extension removable partial dentures and 107 patients with fixed partial dentures. MATERIAL AND METHODS: Dietary logs recorded before the initiation of treatment and 6-months after the baseline period after partial denture treatment were analyzed for 30 nutritional variables of food intakes including total calories, fats, carbohydrates, proteins, fiber, and a number of vitamins and minerals. RESULTS: Both before and after treatment, intakes of various nutrients were more than 25% above or below the RDAs for approximately half of the patients in both groups. No significant differences were observed between the mean scores of the two groups for any of the 30 variables either before or after treatment. However, beneficial treatment effects were seen in subsets of patients with low and high caloric intakes at entry. Both treatments increased the intakes of calories and 27 nutrients in the low caloric group and decreased the intakes of calories and 27 nutrients in the high caloric group. The decreases in the caloric intake and eight nutrients, including total protein, fat, carbohydrates, and cholesterol, were significantly greater (p < 0.05) in the fixed partial denture group than those in the removable partial denture group. CONCLUSIONS: These beneficial effects of partial dentures, if verified by other studies, may have profound clinical implications for the undernourished and obese patients.

Adult↗
PubMed1996

Effects of improvements of poorly fitting dentures and new dentures on masticatory performance.

The effect of four modifications to improve the fit and maxillomandibular relationships of poorly fitting dentures and the insertion of new dentures on masticatory performance was assessed in 21 denture wearers. A 2-week adaptation period was allowed for each of the four modifications and 3 weeks and 12 weeks of adaptation for new dentures. The preferred side masticatory performances were not appreciably affected by either the modifications to improve the fit of the original dentures or the new dentures. In most instances there was a slight decline in performance. Three denture modifications caused significant declines in the carrot-swallowing threshold performances and the new dentures in the peanut-swallowing threshold performance. In other words, the denture wearers had a greater percentage of coarse particles in their bolus ready for ingestion when they chewed with altered or new dentures compared with original dentures. However, they chewed faster and applied fewer chewing strokes with their modified and new dentures. A steady but gradual improvement in the mean performance score with carrots was noted with time after the insertion of new dentures. Dentists and patients need to understand that adaptation to new or modified old dentures may be a long, drawn-out process for some patients.

Adaptation, Psychological↗
PubMed1996

Effects of improvements of poorly fitting dentures and new dentures on masseter activity during chewing.

The effects of four sequential modifications to improve occlusion, vertical dimension, retention, and stability of poorly fitting dentures, and of placing new dentures, on the EMG activity were investigated in 21 denture wearers with a mean age of 67.7 years. Electromyographic recordings of right and left masseter muscles were made while the subjects performed masticatory and swallowing threshold tests and applied static guided forces were measured before and after each modification and at three intervals after the delivery of new dentures. A 2-week adaptation period was allowed for each denture modification. Three- and 12-week adaptation periods were allowed for the new dentures. No significant changes were found in guided static bite force or peak bite force during chewing following any modification or insertion of new dentures. Significant decreases (p < 0.05) from the original poorly fitting denture in preferred side and nonpreferred side muscle activity were found for the preferred side tests with both foods after both the correction of occlusion and 3 mm increase in vertical dimension. Concomitant decreases (p < 0.05) in the masseter closing burst and stroke durations were found and contributed to the reduction in masseter muscle effort. Further reductions (p < 0.01) in masseter closing bursts and stroke durations were observed with new dentures. The results revealed that new dentures or the stabilization of poorly fitting dentures through occlusal correction and restoration of occlusal vertical dimension permits patients to use less muscle effort while chewing and maintaining their initial masticatory performance.

Adaptation, Physiological↗
PubMed1996

Effects of improvements of poorly fitting dentures and new dentures on patient satisfaction.

Clinicians reline or replace dentures to improve occlusion, stability, retention and facial support. They believe that well-fitting dentures will maintain supporting tissues in good health and satisfy patients by improving oral function and self-esteem. In this study, satisfaction of 21 patients with poorly fitting dentures was assessed before and after the dentures were modified to improve occlusion, vertical dimension of occlusion, and retention and stability or the dentures were replaced with new ones. More than 55% of the patients were moderately to fully satisfied with their poorly fitting dentures. Most patients perceived improvements in chewing comfort, chewing ability, eating enjoyment, food choices, security, and speech after each denture modification and with new dentures. The relative importance of the four sequential modifications could not be determined because they were made sequentially and their effects became cumulative. Chewing ability, eating enjoyment, particles under dentures, and food choices were highly correlated with chewing comfort and overall patient satisfaction. The results support the belief of many clinicians that patients benefit from relining of poorly fitting dentures or replacement with new dentures. Improvements in chewing function were perceived by most patients despite the lack of improvement in masticatory performance or masseter muscle activity with modified or new dentures. It is likely that denture wearers perceive chewing ability in terms of chewing comfort rather than ability to comminute food, an objective measure of chewing performance. The latter is not altered markedly by the clinical excellence of dentures.

Adaptation, Physiological↗
PubMed1995

Masseter muscle activity in denture wearers with superior and poor masticatory performance.

A cross-sectional study tested the hypothesis that denture wearers with superior and poor chewing ability use similar masseter muscle effort and biting forces during mastication. Masticatory performance tests on the preferred chewing side and swallowing threshold tests were conducted with peanuts and carrots in 70 denture wearers, 35 with superior (SP) (mean 46.3%) and 35 with poor (PP) (mean 30.7%) masticatory performance. Right and left masseter muscle electromyographic (EMG) activity was recorded during the masticatory tests and peak bite force during chewing was estimated from the bite force--EMG ratios on guided maximal biting trials. Bite force under maximal pressure did not differ significantly between the two groups. Neither the total mean EMG activity of the preferred and nonpreferred side masseter muscles nor the mean peak biting forces exerted by the two groups differed significantly (p > 0.05). This was true when denture wearers restricted chewing to their preferred side for a given number of strokes or chewed the test food freely until ready to swallow. The only significant differences (p < 0.05) were evident in the ratios of the preferred to nonpreferred side masseter EMG activity during chewing. The ratios were 1.2 for peanuts and 1.3 for carrots in the SP group compared to 1.8 for both foods in the PP group. Similar patterns of bilateral activity in the SP group and unilateral activity in the PP group were evident for the swallowing threshold tests. The results indicated that application of more equivalent force by the right and left masseter muscles during unilateral chewing is consistent with improved chewing ability in denture wearers.

Adult↗
PubMed1994

A randomized clinical trial of two basic removable partial denture designs. Part I: Comparisons of five-year success rates and periodontal health.

A randomized clinical trial was undertaken to compare the effectiveness of two partial denture designs, one with I-bar (bar) and the other with circumferential retainers (circumferential), in 134 patients with Kennedy class I and class II edentulous conditions. A total of 30 partial dentures were considered failures, five because of abutment failures and 25 because of the lack of removable partial denture use for eating. The 5-year success rate of 71.3% for the circumferential design did not differ significantly from the 76.6% for the bar design (p > 0.05). There were no discernible changes in the nine periodontal health components of abutment teeth with either of the two designs after 60 months. The results indicate that the two designs do not differ significantly in terms of success rates, maintenance care, and effects on abutment teeth. A well-constructed removable partial denture of either design, supported by favorable abutments and accompanied by a regular recall program offers a satisfactory treatment modality.

Alveolar Bone Loss↗
PubMed1991

Veterans Administration Cooperative Dental Implant Study--comparisons between fixed partial dentures supported by blade-vent implants and removable partial dentures. Part III: Comparisons of masticatory scores between two treatment modalities.

Five Veterans Administration Medical Centers participated in a study to determine the comparative influence of fixed partial dentures (FDPs) supported by endosteal blade implants and removable partial dentures (RPDs) on masticatory performance. The study design, methodology, and success rates have been described in Parts I and II. A total of 232 patients received comprehensive dental care, including RPDs for 118 patients and FPDs for 114. Three standardized masticatory tests were made with peanuts and carrots before treatment. These tests were repeated at 16 weeks following RPD or implant insertion and thereafter at 6, 18, 36, and 60 months. At entry, there were no significant differences in performance scores and chewing time and strokes taken to reach the swallowing threshold between the RPD and FPD groups (p greater than 0.05). After treatment completion, FPDs and RPDs significantly improved the masticatory ability of patients with Kennedy class I or class II edentulous conditions (p less than 0.001). The improvements in performance scores for both test foods were slightly better in the RPD group than in the FPD group, although none of the 30 mean differences was significant (p greater than 0.05). After the baseline period to 60 months, only slight changes in performance scores were observed for both groups. RPDs and FPDs were comparable in improving the chewing efficiency of patients with Kennedy class I and class II partially edentulous conditions.

Adult↗
PubMed1991

Veterans Administration Cooperative Dental Implant Study--comparisons between fixed partial dentures supported by blade-vent implants and removable partial dentures. Part IV: Comparisons of patient satisfaction between two treatment modalities.

This study compares treatment assessments made by two groups of patients with Kennedy class I or class II mandibular edentulous conditions, who received either a removable partial denture (RPD) (N = 115) or one or two fixed partial dentures (FPDs), each supported distally by a blade implant (N = 113). Two questionnaires were administered, one at 16 weeks after the implant or RPD insertion and at the 6-month interval and the other at 18, 36, and 60 months. Marked functional improvements were perceived by a large majority of patients in both groups after the insertion of prosthesis. At 6 months, a higher percent of patients with RPDs than those with FPDs found it easy to clean their RPDs and experienced chewing discomfort, restriction of food choices, feeling of insecurity with their RPDs, and difficulty with their pronunciation. The exclusion of assessments by 25 RPD patients, whose treatment was judged to be a failure functionally, made the mean differences between the two treatments statistically significant (p less than 0.05) only for ease of cleaning in favor of the RPD and fewer restrictions of food choices in favor of the FPD group. At 60 months, significant differences between the percents of patients with the most favorable responses occurred for perceptions of eating enjoyment, food particles seldom getting under the removable partial denture, and improvement in social life in favor of the FPD treatment and for the ease of cleaning the removable partial denture in favor of the RPD treatment. The results seem to support superiority of the FPD in terms of patient satisfaction, but not enough to favor this type of prosthesis over the RPD without consideration of other pertinent factors.

Adaptation, Psychological↗
PubMed1990

Effects of anaesthesia of human oral structures on masticatory performance and food particle size distribution.

Ten persons with intact dentitions performed a series of 6 masticatory tests, employing 5, 10, 20, 40, 80 and 160 strokes to chew standard quantities of peanuts on their preferred chewing side for each of three test conditions: (1) before anaesthesia: (2) after maxillary anaesthesia; and, (3) after maxillary and mandibular anaesthesia (unilateral). A seventh test employing 20 strokes was also repeated on the non-anaesthetized contralateral side. The chewed food was sieved through 5, 10, 20, 40, 80 and 100 mesh screens. The percentage of the ratio of the volume of peanuts that passed through the sieve and the total volume of recovered food provided the performance score for the given sieve. The performance scores increased significantly with the number of stokes and dropped markedly after anaesthesia. The maximum reduction of 19.6% in the mean masticatory performance and 46% in the mean masticatory efficiency occurred after unilateral anaesthesia at 10 mesh particle size in the 20-stroke test. An average of 40 strokes was required after unilateral anaesthesia to achieve almost the same performance achieved with 20 strokes before anaesthesia. The regression slopes, derived from the 5, 10 and 20 mesh particle distributions showed that coarse particles were ground more rapidly than fine particles before anaesthesia. This preferential comminution became less evident after maxillary anaesthesia and was least evident after unilateral anaesthesia. The regression slope for the control peaked at 10 strokes as compared to 20 strokes after unilateral anaesthesia. Thus peripheral sensory impairment affects masticatory efficiency in dentate persons.

Adult↗
PubMed1989

Can two-dimensional echocardiography and Doppler color flow mapping identify the need for tricuspid valve repair?

Tricuspid regurgitation severity was assessed preoperatively with Doppler color flow mapping and these assessments were compared with surgical findings in 90 patients undergoing mitral or aortic valve replacement, or both. Group I (n = 52) required tricuspid valve annuloplasty because tricuspid regurgitation was judged intraoperatively to be severe; in Group II (n = 38), tricuspid valve annuloplasty was not performed because tricuspid regurgitation was judged intraoperatively not to be severe. With use of the apical four chamber and parasternal short-axis imaging planes, the severity of tricuspid regurgitation by Doppler color flow mapping was assessed by comparing the maximal area of tricuspid regurgitant signals with the right atrial area taken in the same frame in which the maximal tricuspid regurgitant signals were noted. This ratio was found to be greater than or equal to 34% (mean 50.2 +/- 11.8%) in 50 (96%) of 52 patients in Group I and less than 34% (mean 27.5 +/- 6.9%) in 36 (95%) of 38 patients in Group II (p less than 0.001). The maximal diastolic tricuspid anulus diameter measured with the same two-dimensional imaging planes was greater than or equal to mm/m2 body surface area (mean 26.7 +/- 5.2 mm/m2) in 46 patients (88%) in Group I and less than 21 mm/m2 (mean 17.8 +/- 2.5 mm/m2) in 36 patients (95%) in Group II (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1989

Veterans Administration Cooperative Dental Implant Study--comparisons between fixed partial dentures supported by blade-vent implants and removable partial dentures. Part II: Comparisons of success rates and periodontal health between two treatment modalities.

Five Veterans Administration centers have participated in a study to determine whether fixed partial dentures (FPDs) supported by blade implants offer an acceptable substitute for mandibular unilateral or bilateral distal-base extension removable partial dentures (RPDs). The study design and methodology have been described in Part I. A total of 232 patients received comprehensive dental care including RPDs for 118 patients and FPDs for 114. Prespecified criteria determined treatment failures. During the 60-month period, treatment failures occurred in 19 FPD patients and 30 RPD patients. Ten FPD failures occurred before and nine after the FPD insertion. Five RPD failures were caused by abutment tooth loss and 25 for not using the RPD while eating. Life table analysis showed 5-year success rates of 84.2% for the FPD and 74% for the RPD. The 17.9% higher FPD success rate in Kennedy class II patients was both statistically and clinically significant. Excluding the 10 early failures, the 5-year FPD success rate was 91.5%. Of the 170 attempted implants, 26 failed, including 12 before the FPD fabrication. Radiographic assessments by a panel of three judges showed no bone deterioration during baseline to 60 months in 29.6%, slight in 25.4%, moderate in 15.9%, marked in 27%, and severe deterioration in 2.1% of the implant posts.

Blade Implantation↗
PubMed1989

Doppler color flow mapping in the evaluation of prosthetic mitral and aortic valve function.

Doppler color flow mapping and color-guided conventional Doppler studies were performed on 119 patients with 126 prosthetic valves (mitral alone in 60, aortic alone in 52 and both mitral and aortic in 7 patients) within 2 weeks of the catheterization study or surgery, or both. The mean pressure gradients derived by color-guided continuous wave Doppler ultrasound correlated well with those obtained at catheterization for both the tissue and mechanical mitral and aortic prostheses (r = 0.85 to 0.87). For the effective prosthetic orifice areas, better correlation with catheterization results were obtained with the tissue mitral (r = 0.94) and tissue aortic (r = 0.87) prostheses than with the mechanical mitral (r = 0.79) and mechanical aortic (r = 0.76) prostheses. The maximal width of the color flow signals at their origin from the tissue mitral prostheses also correlated well with the effective prosthetic orifice area at catheterization (r = 0.81). Doppler color flow mapping identified prosthetic valvular regurgitation with a sensitivity and specificity of 89% and 100%, respectively, for the mitral and 92% and 83% for the aortic prostheses. There was complete agreement between the Doppler color flow mapping and angiographic grading of the severity of prosthetic valvular regurgitation in 90% of mitral and 73.5% of the aortic regurgitant prostheses with under- or overestimation by greater than 1 grade in only two cases. Valvular and paravalvular regurgitation was correctly categorized by Doppler color flow mapping in relation to the surgical findings in 94% of the mitral and 80.5% of the aortic prostheses.

Adult↗
PubMed1988

Color-guided Doppler echocardiographic assessment of aortic valve stenosis.

The severity of valvular aortic stenosis was assessed by Doppler color flow mapping in 100 consecutive patients who underwent successful cardiac catheterization within 2 weeks of the Doppler study. The maximal width of the aortic stenosis jet seen in 61 of these patients (Group A) was measured at the aortic valve. Color-guided continuous wave Doppler examination was used to measure the mean transaortic pressure gradient, and the aortic valve area was estimated using the simplified continuity equation. The aortic stenosis jet was not seen in 39 patients (Group B), and the mean pressure gradient and aortic valve area in these patients were assessed by conventional Doppler echocardiography alone. The mean pressure gradient obtained by continuous wave Doppler study and cardiac catheterization in the 61 Group A patients correlated well (r = 0.90); the correlation was lower in the 39 Group B patients (r = 0.70). The overall correlation for the combined Groups A and B was good (r = 0.82). The aortic valve area estimated by continuous wave Doppler study and cardiac catheterization in 54 Group A patients correlated well (r = 0.92); the correlation in 22 Group B patients was lower (r = 0.71). The correlation for all 76 patients (Groups A and B) was good (r = 0.80). The maximal aortic stenosis jet width also correlated well with the aortic valve area estimated at catheterization in 54 patients (r = 0.90). Group C represented an additional 14 patients in whom the left ventricle could not be entered during cardiac catheterization.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
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↗