Supraventricular tachycardias [SVTs] in a university] children's hospital emergency department: a 3-year experience

In a 3-year retrospective review of 3780 patients who were treated in a University Children's Hospital [ED] along a 3 yr period, 90% were medical cases and 10% were surgical. Admissions due to cardiac diseases represented 20% of all medical cases. During the period of the study there were 55 cases of SVT, representing 1.5% of all admissions and 8.5% of admitted cardiac cases. They were 38 males and 17 females in the age range of 18 days to 12 years. There was a significant predominance of male sex [male: female 2.2:1; P = 0.029]. Age distribution showed that PSVT mainly affected infants more than children, with a mean age of 1.7 yr [P = 0.01]. Among the PSVT patients 3 cases [5.5%] had an underlying cardiac disease while the remaining had lone arrhythmia. In 100%, clinical examination and ECG were diagnostic. Out of all study group, 48 cases [87%] were referred from outpatients clinics while only 7 cases [13%] were referred from inpatient departments of community secondary hospitals. Most referrals were from outpatients [P = 0.02]. The highest admission rates were recorded in summer months and early winter than during spring and fall [P = 0.013]. Appropriate treatment with vagal stimulation, medical treatment, or synchronized DC cardio-version was applied as indicated. In this study 51 patients [92.7%] were able to be discharged to their homes after a mean duration of 2-5 days' hospitalization, while 4 patients [7.3%] died. Two cases died within 24 hours, and other 2 died within 48 hours. Mortality from PSVT after 24 hours of admission represented 0.4% of total mortality of ED admissions. Bad prognosis was associated with: younger age, male sex, outpatient referrals and presence of heart failure at presentation

Influence of filled versus unfilled adhesives on bond strength to dentin and evaluation of the hybrid layer by laser Raman spectroscopy

The purpose of this study was to evaluate the effects of filler incorporation in the adhesive materials i.e., unfilled, microfill and nanofill adhesives, on their shear bond strength to dentin and the chemical nature of the hybrid layer using the micro-Raman spectroscopy

Materials and methods: For bond strength test, the buccal surfaces at a total of 60 freshly extracted non-carious human molar teeth were ground flat. Teeth were divided into three group [n=20] according to the adhesive systems used; prime and Bond 2.1 [unfilled], Optibond Solo [microfill] and XenoIII [nanofill]. The composite resin was applied to the bonded surfaces and light cured. Shear bond strength test was performed using the universal testing machine. For the Raman spectroscopic examination, the occlusal surfaces of a total of 30 freshly extracted human molar teeth were ground flat. Teeth were divided into three groups [n=10] according to the grouping system mentioned before. The adhesive systems were applied to the occlusal surface, and then thee composite resin was applied to the surface and light cured. The specimens were sectioned parallel to the dentinal tubules, the sectioned surfaces of the cut halves were polished with silicon carbide papers. The prepared specimens were examined using the Raman spectroscopy

Results: The results of the present study revealed that the nanofill adhesive system revealed the highest mean shear bond strength values and the lowest values of Residual Double Bond RDB. The microfill adhesive system revealed the lowest mean shear bond strength values and the highest values of RDB. The unfilled adhesive system revealed intermediate results in-between the nanofill and the microfill

Conclusion: Within the limits of the present study it was evident that; Addition of fillers with nanometer particle size to the adhesive system will enhance excellent bonding and sealing of restoration to dentin. Addition of fillers with nanometer particle size to the adhesive system will enhance excellent bonding and sealing of restorations to dentin. Addition of fillers with micron particle size to the adhesive system will impair bonding and sealing of restorations to dentin. The shear bond strength test when combined with microscopic analysis of the adhesive tooth interface can provide useful information regarding the bonding mechanisms of adhesives. The laser Raman spectroscopy is a useful analytical technique for studying the bonding structure of specimens and determining their composition. Further studies are needed to determine the relationship between the amount of residual double bonds and bond strength durability

SEM study into the effects of cavity disinfection procedures on the surface topography and microtensile bond strength to human dentin

Objectives: The aim of the present investigation was to study the effects of NaOCl and glutaraldehyde pretreatment on surface topography of denting and microtensile bond of resin-based composite to dentin

Materials and methods: For SEM examination, a three-millimeter thick dentin discs from the middle third of the crowns of 30 human first molar teeth were obtained. The samples were divided into three group [n=10], relative to the pretreatment utilized i.e., washing only, 2.5% NaOCl or 2% glutaraldehyde. Each group was further subdivided into two subgroups [n=5], relative to the washing used i.e., water or ethanol. Pretreated dentin surfaces were subjected to SEM examination. For microtensile bond strength test, the occlusal surfaces of 30 human first molar teeth were ground flat to the middle third of the crowns. The samples were divided according to the grouping system mentioned before and then bonded with the ethanol based Excite adhesive and restored with the Tetric-ceram hybrid dental composite cores. All samples were sectioned to 1mm[2] sticks and subjected to microtensile bon strength test

Results: SEM results revealed, regardless the washing material used, 2% glutaraldehyde pretreatment of dentin had minimal effects on smear layer removal but it resulted in raising of the collagen fibers at orifices of the dentinal tubules. 2.5% NaOCl pretreatment resulted in complete removal of the smear layer, blugs and collagen fibers at the dentinal tubule orifices. Statistical analysis of the microtensile bond strength values revealed that both pretreatment materials improved the bond strength to dentin, with significant values when water washing was used. Ethanol washing showed significant improvement in the bond strength among all the tested groups

Conclusions: Under the conditions of the present investigation the following conclusions were evident: Washing of cavities with ethanol before acid-etching, although does not affect the dentin surface topography, will enhance sealing and bonding of ethanol based adhesive systems to tooth structures. Pretreatment of dentin with 2% glutaraldehyde, is a promising approach for cavity disinfection, improvement of sealability of restorations and dentin desensitization. Pretreatment of dentin with 2% glutaraldehyde followed by washing with ethanol will enhance excellent sealing. Regarding to its effects on the surface topography of dentin and surface tension of fluids, 2.5% NaOCl application may be considered a new approach to dentin conditioning. In deep cavities, the surface topographic changes found with 2.5% NaOcl pretreatment, although improve bonding to dentin, when followed by acid-etching may invite chemicals used in adhesion steps and restoration to the dental pulp

Microleakage of different adhesive resin systems in class v composite restorations: effect of thermal cycling and load cycling

Objective: the aim of this study was to evaluate the microleakage of five different hydrophilic adhesive resin systems and the effect of thermal and load cycling on microleakage in class V composite restoration

Method and materials: Buccal and lingual class V cavities were prepared with enamel and dentin margins in 75 molar teeth and randomly divided into five groups of 15 molar each. Group 1 was bonded with Syntac Classic [three-bottle] adhesive, group 2 with Excite "one-bottle" fluoride-free adhesive, group 3 with Stae "one-bottle" fluoride containing adhesive, group 4 with AdheSE, two-step, self-etch adhesive and group 5 with Prompt-L-Pop, all-in-one, self-etch adhesive according to the manufacturer's instructions. All preparations were restored with Tetric Cer-am, microhybrid composite resin. From each group 5 molars [10 restorations] were immediately immersed in 0.5% basic fuchsin solution after finishing and kept there for 24 hours to examin microleakage. Other 5 molars of each group were thermocycled [5 - 55°C, 20s dwell time, 500 cycles] and then immersed in the dye solution. The remaining 5 molars of each group were subjected to occlusal load cycling [80-160 N, 5 cycles/sec. 200.000 cycles] prior to immersion in the dye solution. The specimens were sectioned vertically and buccolingually and microleakage was evaluated on a scale of 0 to 3.

Results: For the enamel margins, statistical analysis revealed that there was no significant difference between the tested materials but AdheSE provide the least marginal adaptation while the best results obtained with Syntac Classic. Statistical analysis revealed no significant difference among the groups in dentinal microleakage but AdheSE showed the best result. Both thermal and load cycling had no significant effect on microleakage among the groups either in enamel or dentinal microleakage but the thermocycled and load cycled specimens showed greatest micro-leakage

Conclusion: Among the five adhesive systems used in this study, Syntac Classic had the least microleakage in enamel; however, there was no statistically significant difference among the groups in enamel margins. AdheSE had the.least microleakage in dentin; however, there was no statistically significant difference among the groups on dentin margins. Both thermal and load cycling had no significant effect on microleakage among the groups.

Chromosomal and genetic forms of primary skeletal short stature

Fifty patients [25 males and 25 females with age ranging between three months and 18 years] with primary skeletal short stature were chosen for genetic assessment. Personal [prenatal and natal] and family histories were taken including those of abortions and stillbirths. The patients were clinically examined and their head circumference, weight and heights [US/LS] were measured. Karyotype, skeletal surveys, hormonal, biochemical and metabolic assays were carried out. The results showed that 17 cases had a growth failure associated with chromosomal aberrations, 12 cases suffered from inborn errors of metabolism, 11 cases had osteochondrodysplasias, while those associated with syndromes constituted ten cases. Consanguinity was present in 62%, similar cases in the family in 34%, history of abortions in 40%, disproportion in 30% and subnormal mentality in 72%