Clinical evaluation of a new chemically-cured bulk-fill composite in posterior restorations: 6-month multicenter double-blind randomized clinical trial.

OBJECTIVE: To evaluate the postoperative sensitivity (POS), as well as the clinical performance of posterior restorations using a new chemically-cured bulk-fill composite (Stela Automix and Stela Capsule, SDI) comparing with a light-cured bulk-fill composite after 6 months. METHODS: Fifty-five participants with at least three posterior teeth needing restoration were recruited. A total of 165 restorations were performed on Class I or Class II cavities. After the application of Stela primer, the chemically-cured composite (Stela Automix or Stela Capsule) was inserted. For the light-cured composite group, a universal adhesive (Scotchbond Universal) was applied with a bulk-fill composite (Filtek One). Participants were evaluated for spontaneous and stimulated POS in the baseline, after 48 h, 7 days, and 6 months. Additionally, each restoration was assessed using the updated version of FDI criteria after 6 months. The differences in the proportions of the groups were compared by Cochran test statistics (α = 0.05). RESULTS: Both chemically-cured composites showed a lower risk of POS compared to the light-cured composite at baseline and up to 48 h (p < 0.04). A significantly lower surface luster and texture was observed for the Stela Capsule composite compared to the light-cured bulk-fill composite (baseline and 6 months; p = 0.03). A significant color mismatch was observed for the light-cured bulk-fill composite compared to the chemically-cured composites (baseline and 6 months; p = 0.03). No significant differences were observed in any other item evaluations (p > 0.05). CONCLUSION: Chemically-cured composites exhibit lower postoperative sensitivity and less color mismatch compared to a light-cured bulk-fill composite after 6 months of clinical service. CLINICAL SIGNIFICANCE: The chemically-cured composites appear to be an appealing option for restoring posterior teeth, as they exhibit lower postoperative sensitivity compared to a light-cured bulk-fill composite, both at baseline and up to 48 h, and less color mismatch.

Epidemiology and natural history of cutaneous squamous cell carcinoma in recessive dystrophic epidermolysis bullosa patients: 20 years' experience of a reference centre in Spain.

BACKGROUND: Cutaneous squamous cell carcinoma (cSCC) is the leading cause of death in patients with recessive dystrophic epidermolysis bullosa (RDEB). We provide the management and prognosis of cSCC in RDEB patients at a Spanish reference center. MATERIALS AND METHODS: We retrospectively included patients with RDEB attended in La Paz University Hospital from November 1988 to October 2018. RESULTS: Fourteen patients developed at least one cSCC. Tumors were predominantly well differentiated. Nearly half of the tumors have recurred. Median time to first recurrence was 23.4 months (95% CI: 17.2-29.5). Five patients have developed distant metastases. Median overall survival (mOS) was 136.5 months since the diagnosis of the first cSCC (95% CI: 30.6-242.3). When distant metastases occurred, mOS was 6.78 months (95% CI: 1.94-11.61). CONCLUSIONS: cSCC is a life-threatening complication of RDEB patients. Although tumors are usually well differentiated, they tend to relapse. This is the first Spanish report of cSCC arising in RDEB patients.

Prevalence of antibodies against Entamoeba histolytica in Mexico measured by ELISA.

The prevalence of antibodies against Entamoeba histolytica was studied in the Mexican population using an immunoenzyme assay in solid phase (ELISA) and semiautomatic equipment. The antigen was a mixture of membrane proteins obtained by Triton X-100 extraction from an axenic culture of Entamoeba histolytica HM1-IMSS. The method was standardized by comparing serum samples from amoebic liver abscess patients with healthy volunteers. From the 60,538 samples supplied by the National Seroepidemiology Survey, antibodies were found in 4.49% (4.32-4.65% at 95% confidence limit). More significant titres occurred in the central region of the country. The ratio female to male was 1.25:1. The population living in metropolitan areas had probably been infected at a younger age than those living in the country. Important differences were found in the seroprevalence obtained by ELISA compared with a study which used indirect haemagglutination (IHA) in the same sample frame.

Seroepidemiology of amebiasis in Mexico.

The presence of serum antibodies to Entamoeba histolytica was detected by indirect hemagglutination in a representative sample of the 32 federal entities of the Mexican Republic. This study was designed to include biologic, geographic, social, economic, and educational variables. The total percentage of positive sera was 8.41%. Seroprevalence varied with geographic zones, with the South Central, South Pacific, and Yucatan Peninsula areas showing the highest values (> or = 9%), and the North, Northeast, and Gulf of Mexico areas showing the lowest values (< or = 8.0%). Seroprevalence of anti-E. histolytica antibodies seemed to increase from the northern regions to the southern areas of Mexico. These results indicated that amebiasis is endemic in the Mexican Republic, with areas of high seroprevalence not related to climatic conditions. Exposure to infectious contact with E. histolytica occurred at all ages, with a higher frequency at school age.

Field test of a rapid assessment technique against a probabilistic community survey: operational implications for neonatal tetanus elimination.

Neonatal tetanus (NNT) is a leading cause of neonatal mortality in developing countries and is frequently called 'the silent epidemic'. It is endemic in over 90 countries throughout the world. Incidence is often not known, obstructing cost-effective resource management for control measures. In many developing countries NNT is responsible for one-half of the neonatal mortality and up to one-quarter of infant mortality. Case-fatality rates (CFR) can, even with treatment, reach 80-90%. Operational tools for the rapid identification of NNT risk areas need to be developed for WHO's programme which calls for the elimination of NNT by 1995. Results of a rapid assessment technique, carried out in 1990, were compared with those found in a household survey, which was independently carried out in Jalisco, Mexico, in 1988. One approach used random sample survey techniques in rural communities, which in previous years had reported NNT. Of 40 neonatal deaths, 8 (20%) were attributable to NNT. The annual incidence rate was 4.6/1000 livebirths. Using this as the 'gold standard', a rapid assessment technique was evaluated. The NNT cases seen at health services were randomly matched with other neonatal illnesses obtained from health records and then mapped. Age-specific catchment areas for hospitals under investigation and risk areas for NNT were obtained. Areas without NNT cases but with other neonatal illnesses have been operationally considered to be at low risk for NNT. The use of health services by neonates with other pathologies supports the hypothesis that an NNT case, if it occurred within the same time period and area under investigation, would most probably have been admitted.(ABSTRACT TRUNCATED AT 250 WORDS)

[Seroepidemiology of poliomyelitis in Mexico]. / Seroepidemiología de la poliomielitis en México.

With the massive vaccination campaigns with the inactivated poliomyelitis vaccine starting in 1955 and its oral presentation in 1961, this disease has been controlled in many countries. However, wild polio virus is still transmitted in many developing countries. The study reported in this article had the objectives of estimating the prevalence of antibodies against polio for three types of virus (1, 2 and 3) in the population from 12 to 59 months of age in Mexico and determining the factors associated with the absence of immunity. One section of the National Seroepidemiology Survey (NSS), a study with a representative sample of the Mexican population, included the analysis of 5,260 blood samples for polio seropositivity. These samples were processed using the technique of plaque-reduction-neutralization, with the cut-off for positive titer values at 1:8. The national immunity levels reported for the three types of polio virus were: type 1 (89.8%); type 2 (97.6%); and type 3 (85.4%). The state with the lowest seroprevalence was Campeche, with 59.7 per cent, and the highest observed was Baja California Sur, with 93.0 per cent. The NSS also showed that the immunity level increases with age. There were some differences observed by place of residence; seroprevalences were higher in the urban areas (type one, 93.4%; type two, 98.5% and type three, 88.2%) than in the rural zones (86.6%, 96.8% and 82.9%, respectively). As expected, previous vaccination with three or more doses, referred verbally by the parent or guardian of the child, was associated with higher positivity.(ABSTRACT TRUNCATED AT 250 WORDS)

[Seroepidemiology of measles in Mexico]. / Seroepidemiología del sarampión en México.

Measles is an illness of universal distribution and great social impact. According to the WHO, the annual deaths due to this disease amount to more than a million children in the world. The objectives of this paper are to estimate the seroprevalence of titer of antibodies to measles in the population of 12 to 59 months of age in Mexico and identify the determinants of the immunity state. From the National Seroepidemiology Survey, 5,232 blood samples of children between 12 and 59 months of age, were analyzed, their blood samples were considered positive when the antibody titers were greater or equal to 1:4, tested by hemagglutination inhibition using sensitized erythrocytes. The National seroprevalence was 76.2 per cent. By age group, an increment in positive level was observed age increased. The seroprevalence was 56 per cent in children of 12 to 24 month and 82 per cent for children 48 to 59 month of age. The history of vaccination was obtained verbally; 62.5 per cent of seropositive didn't have vaccination history and 82.5 per cent were of those vaccinated were positive. By place of residence, at rural level (populations less than 2,500 inhabitants) 74 per cent positives, compared to 79 per cent in children of urban areas. All risk factor were significant, based on a univariate analysis, being the one with greatest risk those with negative vaccine history and children of one year of age. The efficiency of the vaccine estimation was of 63.6 per cent. Risk factors related to the vinculation of immunity protection to measles or seropositives were age, and verbal history of vaccination.

[Seroepidemiology of whooping cough in Mexico]. / Seroepidemiología de la tos ferina en México.

This paper presents the results from a serological survey developed in Mexico during 1987 in order to estimate the prevalence of anti Bordetella pertussis antibodies. Agglutinins were measured in 25,666 samples taken from children one to 15 years old living throughout the country. In each case survey covered some data about social and demographic variables such as socioeconomic stratum, number of DPT vaccine doses received and urban or rural settlement, among others. Titers greater than = 1.16 and 1.32 were considered positive; analysis is based on percent prevalence and geometric means of the antibody titers. We found a 65 per cent of total seropositivity, with higher prevalences in the northern and central states. Agglutinins response was higher among females subjects than in males. Children living in rural areas and those classified as belonging to lower socioeconomic level showed the lowest seropositivity prevalences.

[Seroepidemiology of Chagas disease in Mexico]. / Seroepidemiología de la enfermedad de Chagas en México.

The lack of information about Chagas disease in Mexico, as well as the controversy concerning its importance, was the basis for the seroprevalence study of Trypanosoma cruzi in the National Seroepidemiology Survey (NSS). This information was representative of the national situation with regard to disease prevalences and other factors related to the nation's health. Unfortunately the NSS was not a very good information source for the study of trypanosomiasis americana, because its coverage in the disperse rural areas was poor. Nevertheless, the results of the NSS indicated that Chagas disease has an irregular distribution in Mexico with seroprevalences of 1.6, 0.5 and 0.2 for the different dilution levels used in the evaluation. The survey data showed Chagas disease to be less important than that mentioned by other authors. The NSS data confirmed the areas of disease transmission already reported and identified some new ones in Hidalgo, Chiapas and Veracruz. The survey also detected migratory workers with Chagas antibodies in Baja California border cities, a situation which indicates a risk for blood transfusion in areas of the country presumed to be free of the disease. Three quarters (74.5%) of the seropositive population were less than 39 years old. Moreover, the fact that children of less than four years were infected suggests that natural transmission is still very important in some areas. Although the seroprevalences were greater in the lower socio-economic groups, some persons of the higher socio-economic level were also affected. This situation may be explained by the fact that many of these persons own vacation homes in tropical areas.

[Seroepidemiology of cysticercosis in Mexico]. / Seroepidemiología de la cisticercosis en México.

The seroprevalence of cysticercosis indicate that there is a high risk of contact with Taenia solium in Mexico, including both genders and all regions, socioeconomic group, and ages. There are some statistically significant differences in risk of contact, affecting principally the center and southeast of the country, rural areas, handicapped persons, children, old people and women. However, these differences are small. This study emphasizes the fact that the risks of infection by Taenia solium are important in all groups, and therefore, the programs for the control of this disease should be focused at the entire population and emphasize strategies for social development.

[Determining factors of rubella in the 10 to 14 year-old population in Mexico]. / Factores determinantes de la rubéola en población de 10 a 14 años de edad en México.

The clinical and epidemiological importance of rubella relates to its teratogenic effects. When this disease occurs in children, adolescents and adults, it is usually benign. On the other hand, these age groups are source of disease transmission to pregnant women. The serology studies on rubella carried in Mexico prior to 1974, detected seropositivity levels from 87.1 to 97.7 percent in children younger than 14 years of age. In contrast, the National Seroepidemiology Survey (NSS) (1988) reported a much lower seropositivity (69.3%) in children of the same age group, and a rate of 80 percent in women of reproductive age. This situation is a particular problem for Mexico where a high proportion of the pregnancies occur during adolescence. While previous research has commented on descriptive measures of seroprevalences in women, this study, which is based on a logistic regression model, has the purpose of identifying the factors associated with the immunological status of girls between 10 and 14 years of age. The variable which showed the most evident relation to the antibody levels for rubella was years of schooling. The odds ratios (OR) for seropositivity among those who finished secondary schooling was 2.05 times (CI 1.28-2.56) that of the illiterate group. Other statistically significant variables were related to residence, urban vs rural (OR = 1.69; CI 1.48-2.12) and age, 10 vs 14 years (OR = 1.93; CL 1.69-2.42). Based on the multivariate model, it was observed that the girls with a greater risk of seropositivity were those who live in urban areas, attend secondary school, and are 14 years of age, with an OR = 4.05 (G = 6,756.4 and 5,580 gl; p less than .001). The study concludes with the following considerations: the immunological levels of girls from 10 to 14 years of age are low, and the results of the NSS suggest that Mexican public health authorities should evaluate the policy of vaccination against rubeola in the population potentially at risk, and that the factors associated with the disease, in descending order, are: years of schooling, age, and place of residence. It is also necessary to carry out analytic studies which will identify the risks and the etiology of congenital malformations which are likely to have been associated with the occurrence of rubeola virus during pregnancy.