Evaluation of tissue response to MTA and Portland cement with iodoform.

OBJECTIVE: The aim of this study was to evaluate the biocompatibility of Portland cement with the addition of iodoform, compared to MTA (ProRoot). STUDY DESIGN: Eighteen Wistar albino rats were divided into 3 groups of 6 animals each. Polyethylene tubes were filled either with freshly mixed MTA or Portland cement mixed with iodoform (20% wt/wt) and implanted subcutaneously. An empty tube served as control. After 7, 30, or 60 days, the implants together with the surrounding tissues were removed in blocks. Sections were evaluated for the presence and thickness of a fibrous capsule, presence of granulation tissue, and the severity of inflammatory response. Data were submitted to nonparametric statistical analysis with individual comparisons between groups at a significance level of P < 0.05. RESULTS: There were no differences between inflammatory responses at 7 and 30 days. After 60 days from surgical removal, there was significantly more tissue reaction to the MTA and Portland cement compared to the control group. CONCLUSION: There were no significant differences regarding inflammatory responses between MTA and Portland cement with iodoform after 7, 30, or 60 days. After 60 days, the fibrous capsule around the Portland cement appeared more organized than tissue surrounding MTA implants. After 60 days, there was still a significantly increased tissue reaction to the 2 cements compared to the empty polyethylene tubes.     

A QUANTITATIVE ANALYSIS OF ROTARY,ULTRASONIC AND MANUAL TECHNIQUES TO TREAT PROXIMALLY FLATTENED ROOT CANALS

Objective:

The efficiency of rotary, manual and ultrasonic root canal instrumentation techniques was investigated in proximally flattened root canals.

Material and Methods:

Forty human mandibular left and right central incisors, lateral incisors and premolars were used. The pulp tissue was removed and the root canals were filled with red die. Teeth were instrumented using three techniques: (i) K3 and ProTaper rotary systems; (ii) ultrasonic crown-down technique; and (iii) progressive manual technique. Roots were bisected longitudinally in a buccolingual direction. The instrumented canal walls were digitally captured and the images obtained were analyzed using the Sigma Scan software. Canal walls were evaluated for total canal wall area versus noninstrumented area on which dye remained.

Results:

No statistically significant difference was found between the instrumentation techniques studied (p<0.05).

Conclusion:

The findings of this study showed that no instrumentation technique was 100% efficient to remove the dye.     

Boar semen controlled delivery system: analysis of batch seasonal variability

A new encapsulation technology of swine semen is proposed to improve the quality of stored spermatozoa and to obtain the controlled release of viable cells, reducing the number of instrumental inseminations. This technology has been employed to produce barium alginate gel capsules in different seasons; an analysis of batch reproducibility was performed, and total capsule diameter, gel thickness and weight of capsules were determined as indices of batch properties. A seasonal variability was found but each batch was substantially homogeneous. The variability could be related to the biological variability of the semen employed as raw material as well as to the technological process.     

Barium alginate cell-delivery systems: correlation between technological parameters

The most recent trends for the development of several in vitro cell cultures have been oriented towards the cell immobilisation in 3-dimensional scaffolds and cell encapsulation. In fact, an important requirement of cell survival is self-assembly in functional communities, in the presence of an artificial extracellular matrix. In our research, a previously described technique for spermatozoa encapsulation was applied to obtain capsules loaded with an opaque agent as a model, and to perform a formulative study. A process variable, barium ion concentration, was correlated to some capsule properties, such as weight, gel thickness, total and core diameter. Ion concentration can be modified to obtain capsules with predictable characteristics.     

An ecologic study of geographical variation in multiple sclerosis risk in central Sardinia,Italy

We carried out an ecological study in the most archaic area of Sardinia to obtain a reliable estimate of the prevalence of multiple sclerosis (MS) and to investigate the geographical variation in the prevalence across the 100 administrative communes. To estimate the area-specific prevalence rate, we adopted a Bayesian approach that makes it possible to filter out the random variation from the estimates and to obtain a map that reflects the true geographical variation in MS prevalence. 428 resident cases were identified by the case register, including 69 multiplex families. The overall prevalence was 157 per 100,000 inhabitants. The Bayesian area-specific prevalence ranged from 143 to 262/100,000. The high prevalence and its moderate geographical variation in a genetically homogeneous population, as well as the high number of multiplex families observed in the communes with the highest prevalence, could be interpreted as representing a high susceptibility of the population to MS.     

Association between the ancestral haplotype HLA A30B18DR3 and multiple sclerosis in central Sardinia

Association and linkage studies have established the importance of the major histocompatibility complex (MHC) in the susceptibility for multiple sclerosis (MS). We carried out a case-control study to investigate the ancestral haplotype A30B18DR3 and MS in the Nuoro population of Sardinia, which is isolated and genetically distinct from other populations in the Mediterranean basin and characterized by genetic homogeneity, high level of inbreeding, low migration, high prevalence of MS, high frequency of the relevant haplotype, and high past malaria prevalence. Cases and controls were serologically typed for the currently recognized HLA-A, B, and DR antigens. We used a log-linear approach to fit a wide class of models. We tested our hypothesis comparing different models via a likelihood ratio test. We overcame the complication due to unknown gametic phase using expectation-maximization (EM) algorithm as the estimation method. We estimated confidence intervals for odds ratio by using a profile likelihood approach. We found that: (1) the ancestral haplotype A30B18DR3 was associated to MS after allowing for a possible stratification in cases and controls; (2) DR3 allele was conditional independent on disease status, given A30B18 haplotype; (3) there was a tendency for ORs for the high-risk haplotypes to be higher in the high malaria strata; however, this indication did not achieve statistical significance (P = 0.11).     

Cancer mortality in an Italian rubber factory

The purpose of the study was to describe the mortality experience of an Italian cohort of rubber workers and an attempt was made to identify any occupational cancer hazards that might currently be affecting men employed in this type of work. A total of 4917 male workers who first started working in a large rubber factory between 1962 and 1972 have been followed up until 31 January 1983. The number of deaths from all causes and from malignant neoplasms was determined and compared with the expected number of deaths calculated from mortality rates for the province in which the population of the plant lived. Mortality from all causes was 85% of that expected. A slight overall excess of deaths from cancer (SMR = 119) was found; this was entirely due to the excess mortality in the 35-44 age group. In order further to evaluate the possible existence of a cancer risk SMRs were analysed by duration of exposure, time since first exposure, and for specific sites of cancer. A trend in SMR with duration of exposure was found for employees with 10 years of follow up or more. A high risk for some tumour sites emerged.     

Type 1 diabetes among sardinian children is increasing: the Sardinian diabetes register for children aged 0-14 years (1989-1999)

OBJECTIVE: The Sardinian type 1 diabetes register represented the basis to determine the most recent trends and the age distribution of type 1 diabetes incidence among Sardinians <15 years of age during 1989-1999. Part of the data (1989-1998) has been already published by the EURODIAB Group with a lower completeness of ascertainment (87%). The geographical distribution of type 1 diabetes risk was also investigated. RESEARCH DESIGN AND METHODS: The new cases of type 1 diabetes in children aged 0-14 years in Sardinia were prospectively registered from 1989 to 1999 according to the EURODIAB ACE criteria. The completeness of ascertainment calculated applying the capture-recapture method was 91%. Standardized incidence rates and 95% CI were calculated assuming the Poisson distribution. Trend of type 1 diabetes incidence was analyzed using the Poisson regression model. Maps of the geographical distribution of type 1 diabetes risk for the whole time period and separately for 1989-1994 and 1995-1999 were produced applying a Bayesian method. RESULTS: A total of 1214 type 1 diabetic patients were registered yielding to an overall age- and sex-standardized incidence rate of 38.8/100000 (95% CI 36.7-41.1). There was a male excess with an overall male-to-female ratio of 1.4 (1.3-1.8). The increase of incidence during the 11 years analyzed was statistically significant (P = 0.002) with a yearly increasing rate of 2.8% (1.0-4.7). No evidence of an effect of age and sex on this trend has been found. The geographical distribution of type 1 diabetes relative risk (RR) showed that the highest risk areas are located in the southern and central-eastern part of the island and the lowest risk in the northeastern part, even if most of these differences were not statistically significant. This geographical distribution seemed to remain mainly the same between 1989-1994 and 1995-1999. CONCLUSIONS: The homogeneity of diabetes risk and the increase of incidence over the age-groups in the Sardinian population stress the role of an environmental factor uniformly distributed among the genetically high-risk Sardinians.     

Short and long term variation in ultraviolet radiation and multiple sclerosis

We examined the role of ultraviolet radiation (UVR) in persons diagnosed with multiple sclerosis (MS) in four different populations, Italians, Danish, White and African Americans. We tested whether variation in UVR as determined by seasons (short term variation) and solar cycles (long term variation) is related to MS birth month and to survival as measured by lifespan. Cases were selected from three Italian MS Case Registries (2,737); from the United States National Center for Health Statistics (56,020); and from the Danish Multiple Sclerosis registry (15,900). Chi-square tests were used to study the pattern of month of birth distribution in patients with MS comparing with general population data. T-tests were employed to study solar cycles association with lifespan. A surplus of births was observed in June for White Americans. A decrease of births in October and November, though not significant after multiple testing correction, was observed in the three populations. In White American with MS overall, males and females, we found that solar cycle is associated with lifespan. We found that season and solar cycles have some role in MS susceptibility and life duration. However, this is an exploratory analysis and further work is needed to discern the association.