Effects of Remineralizing Agents Based on Calcium Phosphate, Sodium Phosphate, or Sodium Fluoride on Eroded Cervical Dentin.

OBJECTIVES: To evaluate the effect of remineralizing agents on collagen matrix pattern, precipitate formation, and dentinal tubule obliteration in eroded cervical dentin. METHODS AND MATERIALS: One hundred bovine cervical dentin specimens were previously eroded (0.6% hydrochloric acid, pH 2.3, 5 minutes) and then randomized into five groups (n=20): G1, control (without treatment); G2, Desensibilize Nano P (FGM); G3, MI Paste Plus (Recaldent); G4, Regenerate (NR-5); and G5, Desensibilize KF 2% (FGM). These treatments were applied in four sessions with 7-day intervals. During this period, the samples were subjected to an erosive challenge with orange juice (pH 3.8, 5 minutes). The specimens were analyzed by polarized light microscopy with picrosirius red staining, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). RESULTS: The G3 showed a higher concentration of type I collagen than G2 and G5 (p<0.05). The G3 showed greater formation of surface precipitates than that of G1 and G5 (p<0.05). In addition, G4 and G5 showed a greater number of open dentinal tubules than that of G3 (p<0.05). CONCLUSIONS: Calcium phosphate-based remineralizing agents have shown to be a promising alternative treatment for preventing deleterious effects on the eroded dentin collagen matrix. In addition, they promoted precipitate formation and dentinal tubule obliteration on the eroded dentin.

Protocols for Mechanical Cleaning of the Post Space on the Bond Strength Between Root Dentin and Cementation System.

OBJECTIVE: To evaluate the effects of mechanical versus chemical cleaning protocols for cleaning the root dentin surface before cementation of fiberglass posts for their effect on the bond strength, failure mode, and dentinal penetration of the cementing agent using an etch-and-rinse adhesive system on dentin prepared to receive a fiberglass post. METHODS: Forty roots of bovine teeth were endodontically treated and prepared for fiber post cementation. The specimens were randomized into 4 groups of 10: Control group (CO) - irrigation with 2.5% NaOCl; DW group- irrigation with distilled water; RB group - rotating brush for cleaning root canals, and CUI group - continuous ultrasonic irrigation. The fiberglass posts were cemented, and the specimens were immersed in distilled water for 6 months. A push-out test was performed on the cervical, middle, and apical thirds of the samples. Dentinal penetration of the cementing agent and the fracture pattern were evaluated by laser confocal microscopy. Statistical analysis was performed using analysis of variance (ANOVA) and post hoc Tukey tests (α=0.05). Results: The RB and CUI groups showed significantly higher bond strength values when compared to the Control and DW groups (p<0.05). In addition, in the control and DW groups, the apical third presented lower bond strength values when compared to middle and cervical thirds. CONCLUSION: While DW showed the highest incidence of adhesive type failure, CUI resulted in the highest dentinal penetration of the cementing agent (p<0.05). RB and CUI resulted in the highest bond strength between cementation system and root dentin. In addition, CUI favored greater dentinal penetration of fiberglass post cementing agent.

No effect of different bariatric surgery procedures on LINE-1 DNA methylation in diabetic and nondiabetic morbidly obese patients.

BACKGROUND: Bariatric surgery (BS) is proposed as a highly effective therapy for reducing weight and improving obesity-related co-morbidities. The molecular mechanisms involved in the metabolic improvement after BS are not completely resolved. Epigenetic modifications could have an important role. OBJECTIVE: The aim of this study was to evaluate the effect of different BS procedures (Roux-en-Y gastric bypass and laparoscopic sleeve gastrectomy) on global DNA methylation (long interspersed nucleotide element 1 [LINE-1]) in a group of nondiabetic and diabetic severely obese patients. SETTING: University hospital, Spain. METHODS: This study included 60 patients (30 nondiabetic and 30 diabetic severely obese patients) undergoing BS: 31 patients underwent Roux-en-Y gastric bypass and 29 underwent laparoscopic sleeve gastrectomy. Before and 6 months post-BS, anthropometric data, blood pressure, and metabolic parameters were determined. LINE-1 DNA methylation was quantified by pyrosequencing. We used the methylation levels of tumor necrosis factor-α as a control gene promoter. RESULTS: There were no differences between LINE-1 methylation levels at baseline and at 6 months after surgery (66.3±1.6 versus 66.2±2.06). Likewise, there was no statistically significant difference on LINE-1 methylation levels when we stratified according to metabolic status (diabetic versus nondiabetic), nor was there regarding the BS procedure. A strong correlation was shown between LINE-1 methylation levels and weight at baseline both in diabetic and nondiabetic obese patients (r = .486; P<.001). Tumor necrosis factor-α methylation levels increased significantly after BS in the group of diabetic obese patients. CONCLUSION: After BS, global LINE-1 methylation is not modified in the short term. More studies are required to determine if LINE-1 is a stable epigenetic marker, or, on the contrary, if it is susceptible to modification by external factors such as changes in lifestyle or a surgical intervention.

Health interventions for the metal working industry: which is the most cost-effective? A study from a developing country.

This study ranked the cost-effectiveness of health interventions in the metal working industry in a developing country. Data were based on 82 034 workers of the Northern region of Mexico. Effectiveness was measured through 'healthy life years' (HeaLYs) gained. Costs were estimated per worker according to type and appropriate inputs from selected health interventions. 'Hand' was the anatomical region that yielded the most gain of HeaLYs and amputation was the injury that yielded the most gain of HeaLYs. The most effective health intervention corresponded to training, followed by medical care, education, helmets, safety shoes, lumbar supports, safety goggles, gloves and safety aprons. In dollar terms, education presented the best cost-effectiveness ratio (US$637) and safety aprons presented the worst cost-effectiveness ratio (US$1 147 770). Training proved to be a very expensive intervention, but presented the best effectiveness outcome and the second best cost-effectiveness ratio (US$2084). Cost-effectiveness analyses in developing countries are critical. Corporations might not have the same funds and technology as those in developed countries or multinational companies.

Quality differences between rural and urban primary care: the case of a cervical cancer screening programme.

OBJECTIVE: To measure the difference between rural and urban primary care quality in terms of an early cervical cancer detection programme. LOCATIONS: Seven hundred and fifty smear reports from rural primary care units and 750 from urban primary care units were selected at random from three institutions: the Ministry of Health, the largest Mexican social security institution, and one University Hospital, during August 1995-March 1996. Excluded were reports from women who were pregnant, menopausal or those who had undergone hysterectomy, as well as those tested positive for dysplasia and cancer. ACTIVITIES: Quality was measured through indicators and standards set by consensus of recognized field experts, based mainly on recommended national and international parameters. RESULTS: There was no difference between the overall quality of the urban and rural units. Both registered fairly satisfactory levels (achievement: 76.2%; 95% CI: 72.7-77.0%, versus 75.2; 95% CI: 69.8-78.9%, respectively). The quality of the smear sampling was highly unsatisfactory in rural units and unsatisfactory in urban units (achievement: 64.2%; 95% CI: 58.2-70.0%, versus 47.3%, 95% CI: 42-52.7%; P < 0.00001). Quality of coverage was unsatisfactory for both regions. Quality of smear processing and timeliness were highly satisfactory for both rural and urban units. RECOMMENDATIONS: Efforts should be directed toward smear quality improvement, especially in rural units. Health care workers who take smears need training programmes and better instruments. They should receive feedback on smear adequacy from the laboratory. Health education is necessary to improve utilization and programme coverage quality.

Age and sex matched analysis of Hb Lepore trait in a new population in Spain.

A group of subjects with Hb Lepore trait has been found in the region between Extremadura and Toledo in Spain. Clinical, radiological and hematological studies were carried out on 81 cases from 23 families. Asthenia was the sole complaint in seven of forty cases. Abdominal echography showed no cholelithiasis in 16 children under 16 years. Hb Lepore mean was 10.81 +/- 1.97%, range 6.5 to 16.1%, Hb A2 levels were normal and Hb F values were high. Globin chain synthesis in reticulocytes showed a total alpha/beta ratio of 1.89 +/- 0.3. Hematological values from Hb Lepore trait subjects were analyzed according to age and sex and the data compared to beta thalassemia and delta-beta thalassemia cases of matched age and sex. Hb Lepore trait patients had a milder form of thalassemia minor than beta thalassemia patients, with higher levels of hemoglobin, MCV and MCH for all three groups: children under 13 years, males over 14 years and females over 14 years. Children and females with Hb Lepore had higher hemoglobin levels than those with delta-beta thalassemia minor, while no significant difference was found in males.