New technology for the removal of corundum residues on dental implants.

Surface modification is an important measure to improve dental implants. Corundum residues, which are part of current dental implant blasting, on Straumann dental implants, were found to have disappeared in recent publications. We further evaluated this new cleaning technology by evaluating the surface of four different Straumann implants using scanning electron microscopy (SEM) and energy-dispersive radiographic spectroscopy (EDX). The involved technology fits to a Straumann patent involving a dextran coating allowing easy corundum particle removal by aqueous solution.

The randomized shortened dental arch study: tooth loss over five years.

OBJECTIVES: The study was designed to provide clinical outcome data for two treatments of the shortened dental arch (SDA). MATERIAL AND METHODS: In a multicenter randomized controlled clinical trial, patients with complete molar loss in one jaw were provided with either a partial removable dental prosthesis (PRDP) retained with precision attachments or treated according to the SDA concept preserving or restoring a premolar occlusion. No implants were placed. The primary outcome was tooth loss. RESULTS: Of 152 treated patients, 132 patients reached the 5-year examination. Over 5 years, 38 patients experienced tooth loss. For the primary outcome tooth loss, the Kaplan-Meier survival rates at 5 years were 0.74 (95% CI 0.64, 0.84) in the PRDP group and 0.74 (95% CI 0.63, 0.85) in the SDA group. For tooth loss in the study jaw, the survival rates at 5 years were 0.88 (95% CI 0.80, 0.95) in the PRDP group and 0.84 (95% CI 0.74, 0.93) in the SDA group. The differences were not significant. No Cox regression models of appropriate fit explaining tooth loss on the patient level could be found. CONCLUSIONS: The overall treatment goals of a sustainable oral rehabilitation and the avoidance of further tooth loss over longer periods were not reliably achievable. The influence of the type of prosthetic treatment on tooth loss might have been overestimated. CLINICAL RELEVANCE: Regarding our results, the patient's view will gain even more importance in the clinical decision between removable and fixed restorations in SDAs.

The randomized shortened dental arch study: 5-year maintenance.

The scientific evidence concerning prosthodontic care for the shortened dental arch (SDA) is sparse. This randomized multicenter study aimed to compare two common treatment options: removable partial dental prostheses (RPDPs) for molar replacement vs. no replacement (SDA). One of the hypotheses was that the follow-up treatment differs between patients with RPDPs and patients with SDAs during the 5-year follow-up period. Two hundred and fifteen patients with complete molar loss in one jaw were included in the study. Molars were either replaced by RPDPs or not replaced according to the SDA concept. A mean number of 4.2 (RPDP) and 2.8 (SDA) treatments for biological or technical reasons occurred during the 5-year observation time per patient. Concerning the biological aspect, no significant differences between the groups could be shown, whereas treatment arising from technical reasons was significantly more frequent for the RPDP group. When the severity of treatment was analyzed, a change over time was evident. When, at baseline, only follow-up treatment with minimal effort is required, over time there is a continuous increase to moderate and extensive effort observed for both groups (Controlled-trials.com number ISRCTN97265367).

Epidemiological, clinical, and pathomorphological characteristics of epidemic poliomyelitis-like disease caused by enterovirus 71.

In May-September, 1975, an outbreak of epidemic disease clinically and pathomorphologically simulating nearly all known forms of poliomyelitis occurred predominantly among young infants in Bulgaria. Most cases presented benign aseptic meningitis, sometimes with a short period of general cerebra- symptoms. Paralytic forms, such as bulbar polioencephalitis, anterior poliomyelitis, isolated pareses of the facial nerve, occasional cases of encephalomyocarditis, etc., were observed in about 21% of all cases. Over one-fourth of the paralytic cases with bulbar symptoms ended fatally. In March, 1976 another sporadic fatal case of this disease was examined. No new cases occurred in 1977. Histopathological examinations in all fatal cases regularly revealed lesions in the grey matter of the medulla and spinal cord typical of acute anterior poliomyelitis and bulbar polioencephalitis, with some peculiar features of localization and depth of the involvement of the brain stem. The similarity to poliomyelitis and precariously rapid increase in the incidence led to the decision to urgently vaccinate the entire human population with Sabin's live poliovirus vaccine simultaneously in the whole country in order to produce interference with the circulating agent. This aim appeared to have been achieved partially because soon the number of new cases of the disease began to decrease; however, no sharp and complete break in the curve of the incidence occurred. By the time of mass vaccination, the results of virological examinations started before were not yet available. Later, comprehensive complete evidence was obtained that over 25 fatal and many other typical cases of the disease were associated with an enterovirus proved to be antigenically related to enterovirus 71. The diseases in Bulgaria, 1975, differ considerably in the frequency of paralytic forms and in severity from the epidemics caused by enterovirus 71 in Sweden, 1973, Australia, 1972--1973, USA, 1969--1972, and Japan, 1972--1973.

Enterovirus 71 isolated from cases of epidemic poliomyelitis-like disease in Bulgaria.

Virological and serological studies of an epidemic disease in Bulgaria, 1975, were carried out. Epidemiologically, clinically and pathomorphologically, the disease simulated almost all known forms of poliomyelitis, acute stem encephalitis, encephalomyocarditis and aseptic meningitis. The studies completely rules out the participation of polioviruses and provided comprehensive evidence for the etiological role of a peculiar enterovirus subsequently identified as enterovirus (EV) type 71 known in the literature since 1974. Altogether, in 1975 and 1976 from 65 cases of poliomyelitis-like disease (PLD) 92 strains of EV71 were isolated, including 37 strains from the brain and medulla, 1 from the cerebrospinal fluid, 10 from mesenterial lymph nodes and tonsils and 44 from faeces. In addition, in 282 convalescent cases of the disease, diagnostic seroconversion or high titers of antibody to this virus were demonstrated. The most successful virus isolation was achieved by inoculation of green monkey kidney cell cultures and newborn white mice. Bulgarian strains of enterovirus 71 regularly caused paralysis in monkeys and morphological poliomyelitis-like lesions in their CNS, and paralysis and myositis with Zenker necrosis in newborn white mice, cotton rats, Syrian hamsters, and 3-week-old cotton rats. The diseased rodents had much more virus in their mucles than in brains.