• Restorative Dentistry and Endodontics
• /
• v.28 no.1
• /
• pp.89-99
• /
• 2003

The purpose of this study was to investigate the bonding of resin- based root canal sealer, AH26 when the sealer was applied as a thin layer between dentine and gutta-percha surface. In this study forty non-caries extracted human molars and resin-based root canal sealer(AH 26, DeTrey/Dentsply, Germany) were used. Disks of gutta-percha, 6mm in diameter.6mm thick (Diadent/Dentsply, Korea) for thermoplastic obturation were used and dentin surfaces were treated with 2% NaOCl(Group 1) or 2%NaOCl+17% EDTA(Group 3). Disks of gutta-Percha, 6mm in diameter.6mm thick (Diadent/Dentsply, Korea) for conventional obturation were used and dentin surface were treated with 2% NaOCl(Group 2) or 2%NaOCl+17% EDTA(Group 4). Enamel was removed by a horizontal section 1mm below the deepest portion of the central occlusal groove by using a watercooled low speed diamond saw. A second horizontal section was done around cementoenamel junction. Exposed dentin surface was cut to approximately $8{\times}8{\;}mm$ rectangular shape and was ground against 320, 400, 600 grade silicon carbide abrasive paper serially. After grinding, the dentine surface were soaked in a solution of 2% NaOCl for 30 minutes and twenty of specimens were treated with 17% EDTA solution for 1 minute. The treated specimens were washed and dried, Root canal sealer, AH26 was prepared according to the manufacture's instructions The Gutta-percha and dentin surface were coated with a thin layer of the freshly mixed seal or. The specimens were left overnight at room temperature. After their initial set, they were transferred to an incubator at $37$^{\circ}C$ for 72 h. After 72 hours, resin blocks were made. The resin block was serially sectioned vertically into stick of $1{\cdot}1mm$. Twenty sticks were prepared from each group. After that, tensile bond strength f3r each stick was measured with Microtensile Tester Failure patterns of the specimens at the interface between gutta-percha and dentin were observed under the SEM(x1000) and Stereomicroscope (LEICA M42O, Meyer Inst., TX U.S.A) at 1.25 x25 magnification. The results were statistically analysed by using a One-way ANOVA and Tukey's test. The results were as follows; 1. Tensile bond strengths($mean{\pm}SD$) were expressed with ascending order as follows: Group 1, $3.09{\pm}$ 1.05Mpa : Group 2, $6.23{\pm}1.16MPa$ : Group 3, $7.12{\pm}1.07MPa$ : Group 4, $10.32{\pm}2.06MPa$. 2. Tensile bond strengths of the group 2 and 4 used disks of gutta-percha for conventional obturation were significantly higher than that of the group 1 and 3 used fir thermoplastic obturation. (p < 0.05). 3. Tensile bond strengths of the group 3 and 4 treated with 2% NaOC1+17% EDTA were significantly higher than that of the group 1 and 2 treated with 2% NaOCl. (p < 0.05). 4. In analysis of failure patterns at the interface between sealer and gutta-percha, there were observed 49 (61%)cases of adhesive failure patterns and 31 (39%) cases of mixed failures patterns.

• Childhood Kidney Diseases
• /
• v.4 no.1
• /
• pp.77-83
• /
• 2000

Purpose: Pregnancy in transplanted mother is considered as a high-risk pregnancy, and significant incidences of prematurity and low-birthweight(LBW) infants have been reported. The objective of this study is to examine the outcome of pregnancy in transplanted mothers and to evaluate the current growth status in their children. Patients and Methods: We retrospectively reviewed 54 pregnancies in 40 kidney recipients until June 1999. Outcomes of pregnancy were reviewed and assessment of the current growth status in children was performed. Results: 54 pregnancies in 40 recipients were identified; 22 ended in termination of pregnancy because of unwanted pregnancy or therapeutic purposes. And of the other 32, 29 livebirths resulted in 28 recipients. The mean age of conception was $30.3{\pm}3.8$ years, with a mean interval from transplantation to conception of $35.9{\pm}23.2$ months. All patients were maintained on immunosuppressive regimens. Incidence of drug-treated hypertension(HTN) prior to pregancy was $52\%$, HTN during pregnancy, $48\%$; preeclampsia, $41\%$; urinary tract infection, $48\%$; oligohydramnios $4\%$; and no rejection during pregnancy and up to 3month post delivery. Of the 29 liveborn infants, prematurity(<37wk) occurred in $52\%$, LBW(<2500g) in $62\%$, VLBW(<1500g) in $7\%$ and $48\%$ born intrauterine growth retardation(IUGR). Mean gestational age was $36.3{\pm}3.0\;wk$; a mean birthweight, $2.23{\pm}0.6\;kg$; a mean birth-height, $45.1{\pm}3.6cm$. Current mean height standard deviation score (height SDS) was $0.29{\pm}0.91$ and mean weight SDS was $0.62{\pm}1.34$. Only one child($4\%$) under 1 year of age was below 10 percentile in height. Most of children had no medical problems except for 4 children; cleft palate(1), tuberous sclerosis(1), essential hematuria(1), and one child expired due to sepsis. Conclusion: This study showed similar incidence of premaure birth($57\%$) and low birth weight infants($62\%$), but lower incidence of spontaneous abortion($5.6\%$) was observed and compared to other studies. Postnatal growth in majority of children($96\%$) achieved catch-up growth before 1 year. Present study supports a more optimistic view of pregnancy in renal transplant mother and normal growth in their children.