EPA Consensus Project Paper: Accuracy of Conventional and Digital Workflows in Partially Edentulous Cases Restored with FPDs over Implants. A Systematic Review

PURPOSE: To compare conventional and digital workflows in terms of accuracy in partially edentulous cases restored with implant-supported restorations. METHODS: An electronic search in the databases PubMed, Scopus, Web Of Science, and CENTRAL was conducted to identify relevant publications, comparing digital and conventional workflows in partially edentulous cases restored with implant-supported prostheses. RESULTS: 18 articles were included in the systematic review. Ten of the studies were in-vitro, and eight were clinical. Sample sizes varied considerably from 20 to 100. In three studies, three implants were investigated, whereas, in all other instances, accuracy was evaluated on two implants. Substantial heterogeneity in the methodology of the selected studies is evident, which prevents summarising the accuracy outcomes. CONCLUSIONS: Digital impressions showed similar results in terms of accuracy compared to the conventional approach. There is a lack of uniform criteria for the tolerable misfit, which hampers the ability to transfer in-vitro results to clinical situations. A need for a standardised approach in the evaluation of impression and workflow accuracy is warranted to enable the systematisation and analysis of results from different studies.

Prevalence of antibodies against hepatitis C virus and hepatitis B coinfection in healthy population in Bulgaria. A seroepidemiological study.

AIM: Viral hepatitis C is often silent and is sometimes discovered only by routine serologic testing. We investigated healthy adults for seroprevalence of antibodies against hepatitis C virus (HCV), for markers of hepatitis B (HBV) coinfection and for risk factors of transmission blood borne viruses. METHODS: We performed a descriptive cross sectional study for the period 1999-2000. A caseload of 2,211 healthy randomly selected subjects (aged 10-69, both sexes) from a big Bulgarian city gave informed consent for participation and answered a standardized questionnaire. Serum samples were obtained and tested using ELISA method for anti-HCV antibodies, HBV markers (HBsAg, anti-HBc and anti-HBs antibodies), as well as for anti-HIV-1.2 antibodies. RESULTS: The overall anti-HCV seroprevalence was 1.08%, which coincides with the data submitted to WHO for the general Bulgarian population, as well as with the average data for Europe. Higher anti-HCV seroprevalence was ascertained with increasing age except in adolescents, in whom the anti-HCV positivity was high. A great part of the subjects with anti-HCV antibodies -- 62.5% had serological evidence for exposure to HBV. Anti-HCV carriage was in positive correlation with the summarized data for previous morbidity (surgery, blood transfusion and past liver disease), as well as with detecting markers for hepatitis B. In the studied caseload 0.68% had markers of double HCV and HBV infection. Nobody was found as seropositive for HIV-1.2. CONCLUSIONS: The results of our study suggest the need of more stringent measures for prevention and control of HCV infection, including screening focused on different groups of population, precise determination of risk factors for HCV transmission and offering of HBV vaccine to HCV positive individuals to reduce the high risk of double HCV and HBV infection.

Immunoprecipitation against exogenous antigens in the zone of alpha-1, alpha-2 and beta-globulins--a new immune phenomenon?

According to data by H. Zhabilov serum fractions in the zone of alpha 1, alpha 2 and beta-globulins from healthy people form a characteristic precipitation curve in terms of structure and density with the TNP (thymus nuclear protein) and CNP (carcinoma nuclear protein) as antigens when tested in two-dimensional agarose-gel electrophoresis. The observed immune phenomenon has not so far, to the best of our knowledge, been reported in the scientific literature and has profound implications for fundamental and applied immunology. The object of the present study was to confirm Zhabilov's data and study the ontogenetic aspect of the problem. We used 45 sera of children from different age groups, of healthy adult controls, HIV-infected and cancer patients. The sera were tested against the following exoantigens: TNP (thymus nuclear protein), CNP (carcinoma nuclear protein-Viral Genetics Inc, LA), as well as against ST (staphylococcal toxin), SL (streptolysin) and LPS (lipopolysaccharide) from Gram-negative bacteria (National Center for Parasitic and Infectious Diseases, Sofia, Bulgaria). Two-dimensional electrophoresis was used modified after the protocol of UCLA chemical labs. The results of our study show that immediately following birth the precipitation curve is barely discernible reaching the normal shape following 1 month-5 years of age. The precipitation curve from HIV-infected sera and those of cancer patients is similar to that of newborns. The results from our unpublished observations with sera from other biologic species tested against the same antigens show similar results: no curve was observed in fish whereas the reaction was positive with frogs, birds, rabbits and other mammals. This confirmation of the basic biologic law of ontogenesis being a repetition of phylogenesis gives us reason to consider those fractions as participating in the immune maturation of organisms for acquired immune response. There exists a possibility that they might be part of the already known immunomediators or a stage in the transition from non-specific to specific immunoglobulins which have not lost their importance in immunogenesis. The lack of previous studies in this respect and the observation and confirmation of this reaction in two different labs underscore the importance of this new immune phenomenon.

A study on some immunological parameters in infants with salmonellosis.

The phagocytic activity of polymorphonuclears from peripheral blood (PMN) and the qualitative characteristic of lymphocyte populations and circulating immune complexes (CIC) were studied dynamically in 35 infants with salmonellosis. The phagocytic activity of PMNs was evaluated by phagocytic index, phagocytic number, the absolute phagocytic index and the nitroblue tetrazolium test. Lymphocyte populations were determined by immunofluoroscent assay with monoclonal antibodies, and CIC by precipitation with polyethylene glycol. Decreased level of the PMNs phagocytic activity was found in the acute phase of salmonellosis. Both B- and T-lymphopenia with subset dysbalance associated with greater decrease of T4 lymphocytes were identified. During the convalescent period the immunological parameters of the bacteriologically healthy infants were close to normal whereas the Salmonella bacteria carriers demonstrated deviations which persisted in the acute phase of the disease. The immunological parameters studied can be used as additional diagnostic and prognostic criteria in infants with salmonellosis.

A methodological approach for integral assessment of the immune status.

The proposed approach for assessment of the immune status includes investigation of 21 immune indices of the three effector mechanisms of the immune system--the phagocytic activity, the cellular immunity and immunoregulatory cells and the humoral immunity. Standardized reference values for the corresponding immune indices were obtained using a statistical matrix. These values take into consideration the relationships between the immune reactions, thus allowing integral assessment of immune reactivity. This method permits diagnosis of immunodeficient conditions and control of immunocorrecting therapy. It also enables screening studies to be conducted on the immune status of subjects living in ecologically endangered regions.