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Marcel Zwahlen

Publications and source records attributed to Marcel Zwahlen.

29 records · Page 2Linked to original sources
PubMed2004

A systematic review of the survival and complication rates of fixed partial dentures (FPDs) after an observation period of at least 5 years. II. Combined tooth--implant-supported FPDs.

OBJECTIVES: The objective of this systematic review was to assess the 5- and 10-year survival of combined tooth-implant-supported fixed partial dentures (FPDs) and the incidence of biological and technical complications. METHODS: An electronic MEDLINE search supplemented by manual searching was conducted to identify prospective and retrospective cohort studies on FPDs with a mean follow-up time of at least 5 years. Patients had to have been examined clinically at the follow-up visit. Assessment of the identified studies and data abstraction was performed independently by two reviewers. Failure and complication rates were analyzed using random-effects Poisson regression models to obtain summary estimates of 5- and 10-year survival proportions. RESULTS: From a total of 3844 titles and 560 abstracts, 176 articles were selected for full-text analysis, and 13 studies met the inclusion criteria. Meta-analysis of these studies indicated an estimated survival of implants in combined tooth-implant-supported FPDs of 90.1% (95 percent confidence interval (95% CI): 82.4-94.5%) after 5 and 82.1% (95% CI: 55.8-93.6%) after 10 years. The survival rate of FPDs was 94.1% (95% CI: 90.2-96.5%) after 5 and 77.8% (95% CI: 66.4-85.7%) after 10 years of function. There was no significant difference in survival of tooth and implant abutments in combined tooth-implant FPDs. After an observation period of 5 years, 3.2% (95% CI: 1.5-7.2%) of the abutment teeth and 3.4% (95% CI: 2.2-5.3%) of the functionally loaded implants were lost. After 10 years, the corresponding proportions were 10.6% (95% CI: 3.5-23.1%) for the abutment teeth and 15.6% (95% CI: 6.5-29.5%) for the implants. After a 5 year observation period, intrusion was detected in 5.2% (95% CI: 2-13.3%) of the abutment teeth. Intrusion of abutment teeth were almost exclusively detected among non-rigid connections. CONCLUSION: Survival rates of both implants and reconstructions in combined tooth-implant-supported FPDs were lower than those reported for solely implant-supported FPDs (Pjetursson et al. 2004). Hence, planning of prosthetic rehabilitation may preferentially include solely implant-supported FPDs. However, anatomical aspects, patient centered issues and risk assessments of the residual dentition may still justify combined tooth-implant-supported reconstructions. It was evident from the present search that tooth-implant-supported FPDs have not been studied to any great extent and hence, there is a definitive need for more longitudinal studies examining these reconstructions.

Algorithms↗
PubMed2004

A systematic review of the survival and complication rates of fixed partial dentures (FPDs) after an observation period of at least 5 years.

OBJECTIVES: The objective of this systematic review was to assess the survival of cantilever fixed partial dentures (FPDs) and the incidence of biological and technical complications. METHODS: An electronic MEDLINE search supplemented by manual searching was conducted to identify prospective and retrospective cohort studies on FPDs with a mean follow-up time of at least 5 years. Patients had to have been examined clinically at the follow-up visit. Assessment of the identified studies and data abstraction was performed independently by two reviewers. Failure and complication rates were analyzed using random-effects Poisson regression to obtain summary estimates of 10-year survival proportions. RESULTS: From a yield of 3658 titles and 211 abstracts, 81 articles were selected for full-text analysis, finally resulting in 13 studies that met the inclusion criteria. Meta-analysis of these studies resulted in an estimated survival rate of cantilever FPDs of 81.8% (95 percent confidence interval (95% CI): 78.2-84.9%) and success rate (free of all complications) of 63% (95% CI: 54.7-70.2%) after 10 years. The most common biological complication was loss of pulp vitality (32.6%) followed by caries at abutment teeth (9.1%). After a 10-year observation period 2.6% of the FPDs were lost as a result of dental caries and 1% due to recurrent periodontitis. The most frequent technical complication was loss of retention (16.1%) followed by material fractures (5.9%). The cumulative incidence of fractures of abutment teeth was 2.9% and 2.4% of the FPDs were lost as a result of abutment tooth fracture after an observation period of 10 years. CONCLUSION: This systematic review on cantilever fixed partial dentures indicated that survival and success rates of cantilever fixed partial dentures were lower than those of conventional end-abutment supported FPDs described in a review by Tan et al. (2004) and biological and technical complications were frequent.

Algorithms↗
PubMed2003

Comparison of the effectiveness of two mumps vaccines during an outbreak in Switzerland in 1999 and 2000: a case-cohort study.

In two recent nation-wide outbreaks of mumps in Switzerland two-thirds of young children with clinical mumps had a history of primary vaccination. On average, measles-mumps-rubella (MMR) vaccination coverage is 80%. Two types of vaccine are commonly used: Jeryl-Lynn and Rubini. The effectiveness of the latter has been questioned in several publications. The authors therefore compared Rubini to Jeryl-Lynn in a case-cohort study. The study included 111 young children with clinical mumps who had been reported to the Swiss Federal Office of Public Health (SFOPH) by primary care physicians of the Swiss Sentinel Surveillance Network (SSSN) between January 1999 and May 2000. Sentinel physicians also sampled 661 children from the same birth cohort as the cases. While we found no evidence for the effectiveness of the Rubini strain, vaccination with the Jeryl-Lynn strain was 70% effective against clinical mumps. Furthermore, children vaccinated with the Rubini strain attended primary health care more frequently with clinical mumps than those who had received Jeryl-Lynn (odds ratio: 2.4; 95% confidence interval (CI): 1.3, 4.7). Restricting the analysis to laboratory confirmed cases increased the odds ratio to 18.4 (95% CI: 2.5, 811.2). Our study confirms the low effectiveness of the Rubini strain vaccine in the field. This vaccine should therefore be considered inappropriate for the control and elimination of mumps and its use should be discontinued. As other vaccines with comparable quality and safety standards and a substantially higher effectiveness are available the MMR vaccination program in Switzerland will not be compromised if the use of Rubini is no longer recommended.

Cohort Studies↗
PubMed2003

Swiss primary care physicians' knowledge, attitudes and perception towards genetic testing for hereditary breast cancer.

PURPOSE: The Swiss Institute for Applied Cancer Research's (SIAK) Network for Cancer Predisposition Testing and Counseling was established in 1999. To define its role in the care of individuals with inherited cancer predisposition, attitudes, knowledge and perception of primary care physicians towards genetic counseling and testing for hereditary breast cancer were examined. METHODS: A questionnaire was sent to 1391 primary care physicians in private practice in the German-speaking Canton of Zürich. RESULTS: 628 (45%) questionnaires were returned: 319/778 (41%) general practitioners, 156/367 (43%) internists, 118/218 (54%) obstetrician-gynecologists and 22/28 (76%) oncologists answered. Socio-demographic characteristics were: 74% males and 26% females with a mean age of 51 and a mean number of 14 years in private practice. Fifty-two percent of responding physicians approved of genetic susceptibility testing and seventy-seven percent would recommend it to individuals at risk if asked for it. Of the responding physicians, 47% wanted to disclose test results and discuss its consequences and 79% wanted to provide long term care and support, whereas only 36% and 9%, respectively, assigned these tasks to specialized cancer genetics services. Eight knowledge questions had to be answered: 290 (46%) gave 0-2 correct answers, 284 (45%) gave 3-5 and 54 (9%) gave 6-8 correct answers. CONCLUSIONS: Our findings demonstrate that the majority of responding primary care physicians in the Canton of Zürich approve of genetic testing for hereditary breast cancer and want to play a central role in the management of these families, but lack the knowledge to do so efficiently. Our findings underline the importance of educational programs in cancer genetics.

Adult↗
PubMed2003

Women's perception of the benefits of mammography screening: population-based survey in four countries.

BACKGROUND: Screening programmes are often actively promoted to achieve high coverage, which may result in unrealistic expectations. We examined women's understanding of the likely benefits of mammography screening. METHODS: Telephone survey of random samples of the female population aged > or =15 years in the US, UK, Italy, and Switzerland using three closed questions on the expected benefits of mammography screening. RESULTS: A total of 5964 women were contacted and 4140 women (69%) participated. Misconceptions were widespread: a majority of women believed that screening prevents or reduces the risk of contracting breast cancer (68%), that screening at least halves breast cancer mortality (62%), and that 10 years of regular screening will prevent 10 or more breast cancer deaths per 1000 women (75%). In multivariate analysis higher number of correct answers was positively associated with higher educational status (odds ratio [OR] = 1.44, 95% CI: 1.25, 1.66) and negatively with having had a mammography in the last 2 years (OR = 0.86, 95% CI: 0.73, 1.01). Compared with US women (reference group) and Swiss women (OR = 0.98, 95% CI: 0.82, 1.18) respondents in Italy (OR = 0.61, 95% CI: 0.50, 0.74) and the UK (OR = 0.73, 95% CI: 0.60, 0.88) gave fewer correct answers. CONCLUSION: In the US and three European countries a high proportion of women overestimated the benefits that can be expected from screening mammography. This finding raises doubts on informed consent procedures within breast cancer screening programmes.

Adolescent↗
PubMed2002

Determination of the prevalence of infection with Mycobacterium tuberculosis among persons vaccinated against Bacillus Calmette-Guérin in South Korea.

The prevalence of tuberculous infection was estimated among 12,032 persons with a Bacillus Calmette-Guérin (BCG) vaccination scar and 7,788 persons without such a scar who participated in a nationwide tuberculin skin test survey conducted in the Republic of Korea in 1975. The analysis was built upon mixture models that captured the heterogeneity of indurations arising from tuberculous infection, cross-reactions due to infection with environmental mycobacteria, and BCG vaccination. The three distributions were allowed to vary by age, sex, and BCG vaccination status in the Bayesian manner, according to the prior opinion of the authors. Estimated prevalences of tuberculous infection were similar among persons with a BCG scar and persons without one: 7.5% (95% credibility interval (CI): 3.1, 12.5) and 5.2% (95% CI: 4.2, 6.3), respectively, at age 0-4 years and 87.3% (95% CI: 84.0, 90.2) and 84.0% (95% CI: 81.9, 85.8), respectively, at age 25-29 years. From this analysis it can be concluded that mixture models allow investigators, for the first time, to estimate the prevalence of tuberculous infection not only in unvaccinated persons but also in the BCG-vaccinated population. Mixture models are a versatile tool for analyzing diagnostic test data and more general classification problems of considerable complexity.

Adolescent↗
PubMed2002

National laboratory reports of Chlamydia trachomatis seriously underestimate the frequency of genital chlamydial infections among women in Switzerland.

BACKGROUND: Public health authorities want to evaluate their sexually transmitted disease (STD) surveillance systems to promote the most effective use of health resources. GOAL: The goal of this study was to estimate the sensitivity of national laboratory reports of in Switzerland (the proportion of cases detected by national laboratory reports). STUDY DESIGN: A cross sectional prevalence study was conducted by the Swiss Sentinel Surveillance Network of Gynecologists in 1998. Two groups of women aged less than 35 years were included in the study: those having a first consultation for pregnancy and those having a routine check-up. RESULTS: A total of 1589 women were tested for. The prevalence among pregnant women (n = 817) was 1.3%, and that among sexually active women (n = 772) was 2.8%. Using the prevalences observed among check-up women, we estimate that there were at least 24,400 infections in Switzerland among women aged 20 to 34 years in 1998 (95% CI: 14,300-34,300). The number of laboratory reports of in this age group was 1,150 in 1998. CONCLUSION: Our study suggests that the sensitivity of national laboratory reports of in 1998 was less than 5% for women aged 20 to 34 years.

Adult↗
PubMedDate not supplied

Exercise capacity in subjects with type 1 diabetes mellitus in eu- and hyperglycaemia.

BACKGROUND: Circumstantial evidence suggests that an increase in plasma glucose availability improves exercise capacity in subjects with type 1 diabetes mellitus. The aim of this study was to assess exercise capacity in eu- and hyperglycaemic conditions in subjects with type 1 diabetes. METHODS: Eight moderately exercise-trained male subjects with type 1 diabetes on continuous subcutaneous insulin infusion were studied. Using identical insulin infusion rates, the patients were randomly allocated to perform two stepwise ergometer tests in eu- and hyperglycaemic clamp conditions. The primary endpoint was the peak power output; the secondary endpoints comprised the rate of perceived exertion, lactate levels, heart rate, and respiratory exchange ratio. RESULTS: Eu- and hyperglycaemic clamp conditions were observed at a plasma glucose concentration of 5.3 +/- 0.6 mmol/L and 12.4 +/- 2.1 mmol/L, respectively (mean +/- SD), and remained stable throughout the physical exercise. Insulin levels were similar in both conditions. Hyperglycaemia did not result in a significant increase in the peak power output compared to euglycaemia (mean paired difference of 4.96 W, 95% CI - 11.3 to 21.2, p = 0.49). Hyperglycaemia did not have a significant impact on the secondary endpoints compared to euglycaemia. Sensitivity analyses confirmed these results. CONCLUSIONS: In subjects with type 1 diabetes, exercise capacity is not influenced by hyperglycaemia. Comparable levels of lactate and similar respiratory exchange ratio suggest that an increase in extracellular glucose availability did not translate into increased intracellular glucose oxidation.

Blood Glucose↗
PubMedDate not supplied

Cancer in first degree relatives of Latin American women with cervical cancer. A pilot study.

BACKGROUND: Cervical cancer is the most frequent cancer of women in Latin America, being strongly associated with infection by certain human papillomavirus (HPV) types. Familial cancer clustering can be due to interactions between infectious agents and host genes. MATERIALS AND METHODS: A cancer-related family history of first degree relatives was elicited in 335 women with invasive cervical cancer (probands) and in 335 women without cancer (controls) in Honduras, Peru and Uruguay, and the frequency of reported familial cancers among the relatives was compared between proband and control relatives. RESULTS: The mean age at the time of interview was 49.8 years for the probands and 50.1 years for the controls (NS). 3852 proband relatives had 114 primary cancers of the following major localisations: 22 uterus, 16 lung, 12 stomach and 64 others. 3333 control relatives had 101 primary cancers of the following major localizations: 18 uterus, 13 stomach, 12 breast, 11 intestinal, 10 lung and 37 others. The frequency of all cancer diagnosis among proband relatives was similar to the frequency among control relatives (odds ratio= 1.01; 95% confidence interval: 0.69-1.47). Nine haemolymphatic malignancies were reported among proband relatives versus 2 in control relatives (odds ratio=3.46; 95% confidence interval: 0.74-16.29). CONCLUSION: All cancer combined did not appear to be more frequent in first degree relatives of women with cervical cancer diagnosis, but haemolymphatic malignancies, a minor part of the cancer burden, may be overrepresented in relatives of women with cervical cancer, pointing to a pathogenic role of familial e.g. hereditary, immunosuppression.

Case-Control Studies↗