Effects of Slow Programmable Cryopreservation on Preserving Viability of the Cultured Periodontal Ligament Cells from Human Impacted Third Molar

PURPOSE: This study was conducted to determine cell viability and differentiation capability of human periodontal ligament (PDL) cells and to elucidate the effects of cryopreservation on the activity of human third molar PDL cells by comparing PDL cells with and without cryopreservation. MATERIALS AND METHODS: Human PDL fibroblasts obtained from immature third molars were cultured and divided into two groups. The experimental group was cryopreserved with a slow freezing rate of 0.5degrees C/min from 4degrees C to -35degrees C followed by plunging in liquid nitrogen at -196degrees C and cultured after fast thawing. The control group was cultured without cryopreservation. Cell viability, growth capacity and morphology were evaluated in both groups. Bivariate statistics were used to compare 2 groups and linear mixed model analysis was used to investigate the growth trends difference over time. RESULT: Cell viability and growth capacity were not significantly different between the 2 groups (P>0.05). Cultured cell of both groups showed fibroblast-like in appearance, and there were no significant differences in morphology between 2 groups. The mixed model analysis revealed no significant difference of growth capacity between 2 groups over time (beta=-0.0009; P=0.138). CONCLUSION: This study demonstrates that cryopreservation under control does not affect the biological properties of PDL cells, supporting the feasibility of autotransplantation of cryopreserved impacted third molars.

The retrospective study of marginal bone loss around dental implants according to different autogenous bone grafts

INTRODUCTION: This study examined the cumulative resorption of implants placed in a severely atrophic mandible and analyzed the radiologic bone resorption in the marginal bone, after an autogenous bone graft including both block and particulates that had been harvested from the ramus and iliac crest. MATERIALS AND METHODS: A retrospective study was performed on patients who had bone grafts for augmentation followed by implant installation in the mandible area from 2003 to 2008. Twelve patients (6 men and 6 women) who received 34 implants in the augmented sites were evaluated. Cumulative radiologic resorption around the implants was measured immediately, 3 months, 6 months and 12 months after implant installation surgery. RESULTS: The installed implant in grafted bone showed 0.84 mm marginal bone resorption after 3 months and 50% total cumulative resorption after 1 year. The mean marginal bone resorption around the implant installed in the grafted bone was 0.44 mm after 3 months, 0.52 mm after 1 year, after which it stabilized. The implant survival rate was 97% (failed implant was 1/34). Marginal bone resorption of the installed implant in the autogenous onlay block bone grafts was 0.98 mm after 3 months, which was significantly higher than that of a particulated bone graft (0.74 mm) (P<0.05). CONCLUSION: An autogenous graft including block type and particulate type is a predictable procedure for the use of dental implants in a severely atrophic mandible. Implant placement in augmented areas show a relatively high survival and minimal bone loss, as revealed by a radiologic evaluation.

Tricuspid Regurgitation Due to Rupture of a Chordae in Newborn: A Report of One Cases / 대한흉부외과학회지

Tricuspid regurgitation due to rupture of a chorda is a rare disease in newborns. Recently, we experienced one day old male with tricuspid regurgitation due to rupture of a chorda of anterior papillary muscle, and who had suffered from severe hypoxemia, acidosis, cyanosis, and bradycardia. Preoperative diagnosis was pulmonary atresia with intact ventricular septum, massive tricuspid regurgitation, and patent ductus arteriosus by echocardiogram, which demonstrated no flow through the pulmonic valve. At operation, the pulmonic valve was intact and a chorda of anterior papillary muscle was ruptured. Tricuspid regurgitation was corrected successfully with reconstruction of the chorda. Postoperative course was complicated by pneumonia and sepsis, but the infant recovered and discharged at postoperative 20 days.