Association of ficolin-2 gene polymorphisms and susceptibility to systemic lupus erythematosus in Egyptian children and adolescents: a multicenter study.

BACKGROUND: Pediatric-onset SLE (pSLE) is a multisystem autoimmune disease. Recently, the ficolin-2 (FCN2) gene has emerged as a potential candidate gene for susceptibility to SLE. OBJECTIVES: The objective of this study was to evaluate the association of the FCN2 gene polymorphisms at positions -986 (G/A), -602 (G/A), -4 (A/G) and SNP C/T (rs3124954) located in intron 1, with susceptibility to pSLE in Egyptian children and adolescents. METHODS: This was a multicenter study of 280 patients diagnosed with pSLE, and 280 well-matched healthy controls. The FCN2 promoter polymorphisms at -986 G/A (rs3124952), -602 G/A (rs3124953), -4 A/G (rs17514136) and SNP C/T (rs3124954) located in intron 1 were genotyped by polymerase chain reaction, while serum ficolin-2 levels were assessed using enzyme-linked immunosorbent assay. RESULTS: The frequencies of the FCN2 GG genotype and G allele at -986 and -602 positions were significantly more represented in patients with pSLE than in controls (p < 0.001). Conversely, the FCN2 AA genotype and A allele at position -4 were more common in patients than in controls (p < 0.001). Moreover, patients carrying the FCN2 GG genotype in -986 position were more likely to develop lupus nephritis (odds ratio: 2.6 (95% confidence interval: 1.4-4.78); p = 0.006). The FCN2 AA genotype at position -4 was also identified as a possible risk factor for lupus nephritis (odds ratio: 3.12 (95% confidence interval: 1.25-7.84); p = 0.024). CONCLUSION: The FCN2 promoter polymorphisms may contribute to susceptibility to pSLE in Egyptian children and adolescents. Moreover, the FCN2 GG genotype at position -986 and AA genotype at position -4 were associated with low serum ficolin-2 levels and may constitute risk factors for lupus nephritis in pSLE.

Microleakage at the interface between composite veneering material and precious alloy surface constructed either by new metallurgical sintering technique or the conventional casting technique.

The new metallurgical sintering technique in construction of precious metallic structure of the resin veneered restorations was introduced recently in the prosthetic dental work. This study compared the microleakage at the interface between photocured composite veneering material and gold platinum alloy surface constructed either by the new sintering technique or the conventional casting technique. Two chemically adhesive systems were used, a) silicoater and b) Lee metal primer, in order to retain the veneering material. The samples were subjected to thermal cycling and the procedures used in determination microleakage were the radioactive isotope and the autoradiograph methods. Two time intervals were compared 1--one month and 3--three months. It was concluded that the two different techniques used in construction of the metallic part showed no statistical significant difference in microleakage at their interface with the veneering material retained either by silicoater or Lee metal primer systems.

Influence of linear expansion of two different non metallic core materials upon cervical marginal accuracy of full veneer crowns.

The effect of water sorption and linear expansion of two different non metallic core materials: 1) Composite and 2) Reinforced glass ionomer on the cervical marginal seating of cast metal crowns was investigated in this study. Thirty freshly extracted sound mandibular molar teeth were used in this study. The teeth were machined cut to simulate average dimensions of a prepared lower second premolar tooth with chamfer finish line. The teeth were decoronated 2 mm above the finish line then specially prepared to receive equal volumes of either pin retained composite or pin retained reinforced glass ionomer. The teeth after that were restored with full coverage metal crowns. Ten of each type of core samples were immersed in 37 degrees C normal saline while the remaining samples were maintained dry (control). The vertical cervical marginal accuracy of the crowns were microscopically measured with 1 micron accuracy before immersion and after 6, 12 hours and every day of the following ten days of saline immersion. The statistical analysis of the results revealed that composite core immersed in saline solution at 37 degrees C possessed dimensional instability with the maximum linear change between the first and the second day. Also the reinforced glass ionomer core showed no effect upon the cervical marginal seating of the overlying full coverage cast metal crown.

Prevention of tooth hypersensitivity caused by the hydrodynamic action of zinc phosphate and composite resin luting cements (SEM) study.

This study was done to determine the role of cement liner as a reducing factor to the fluid movement in order to prevent tooth hypersensitivity according to the hydrodynamic theory during cementation of crowns. A total of fourty freshly extracted intact lower molar were selected for this study. After conventional tooth preparation the teeth were sub-divided into four equal groups to identify the role of cement liner in preventing the penetration of used cement into the dentinal tubules. Scanning electron microscopic study proved the efficiency of glass ionomer liner on preventing cement penetration into the dentinal tubules.

Microleakage of oral microflora for porcelain and some porcelain repair materials--in vitro study.

Repairing porcelain fractures has become of interest to the dentist. The intra oral fracture of metal-ceramic restorations may be due to inadequate metal support, excessive porcelain thickness, technical flaws, and occlusal forces. Various techniques for intra oral porcelain repair have been suggested. The resin-porcelain junction has been in question since the advent of the porcelain veneer for cast metal restorations. To enhance this, several intermediary products and techniques have been developed to increase the chemical bond between the fractured porcelain and the repair materials. Clinical procedures for porcelain repair has required roughening of porcelain surface with a rotary abrasives, application of silane followed by composite to replace the contour of the restoration (2, 13, 14). Laboratory data suggested that the strong bond of the repair materials was developed.

Biological influence of some crown and bridge restorative materials finished and polished by different techniques.

Fixed restorations should satisfy certain biologic requirements and they must not be injurious to the surrounding living tissues as pulp, periodontal ligament, alveolar bone and gingiva. It is best to terminate preparations above the gingival margin but for retention and esthetics considerations the margins of the fixed restorations could be placed subgingivally. In recent years, the biologic effects of dental restorative materials on the gingiva and periodontal tissues have been better appreciated. A rough surface restoration attracts and retains bacterial plaque and irritates the surrounding soft tissues which is injurious to the living supporting structure of the abutments.