Evaluation of a canine small intestinal submucosal xenograft and polypropylene mesh as bioscaffolds in an abdominal full-thickness resection model of growing rats

We evaluated the biological scaffold properties of canine small intestinal submucosa (SIS) compared to a those of polypropylene mesh in growing rats with full-thickness abdominal defects. SIS is used to repair musculoskeletal tissue while promoting cell migration and supporting tissue regeneration. Polypropylene mesh is a non-resorbable synthetic material that can endure mechanical tension. Canine SIS was obtained from donor German shepherds, and its porous collagen fiber structure was identified using scanning electron microscopy (SEM). A 2.50-cm2 section of canine SIS (SIS group) or mesh (mesh group) was implanted in Sprague-Dawley rats. At 1, 2, 4, 12, and 24 weeks after surgery, the implants were histopathologically examined and tensile load was tested. One month after surgery, CD68+ macrophage numbers in the SIS group were increased, but the number of CD8+ T cells in this group declined more rapidly than that in rats treated with the mesh. In the SIS group, few adhesions and well-developed autologous abdominal muscle infiltration into the SIS collagen fibers were observed. No significant differences in the tensile load test results were found between the SIS and mesh groups at 24 weeks. Canine SIS may therefore be a suitable replacement for artificial biological scaffolds in small animals.

Evaluation of the effect of different surface treatments on the retention of posts: A laboratory study.

Background and Objectives : There are numerous post and core systems variety of materials. Several methods are used to increase the retentive strength.The present study was conducted with the purpose of analysis of the effect of surface treatment with ethyl alcohol, resin primer and air-borne alumina particle abrasion on retention of glass fiber posts, carbon fiber posts and cast metal posts Materials and Methods : Surface treatment of glass fiber posts, carbon fiber posts and cast metal posts was done with ethyl alcohol, resin primer and air-borne alumina particle abrasion and cemented with dual cure resin cement into the post spaces prepared in the teeth. For the Retentive force test, a screw driven universal testing machine was used to apply tensile load to the post. The force required to dislodge each post from prepared post space was recorded. Statistical Analysis : Comparison of the mean retentive strength was done using two-way Analysis of Variance (ANOVA) followed by Bonferroni method for multiple comparisons. Results : Significant difference in the retentive strength between air borne alumina particle abrasion and resin primer treated posts was (P < 0.001) noticed. Further, there was no significant difference between ethyl alcohol and resin primer treated posts Conclusion : Air-borne alumina particle abrasion increased the retentive strength of all the type of posts used in this study. Treating the surface of the posts with resin-primer and ethyl alcohol produced no statistically significant difference in the retentive strength.

Comparative Tensile Load Study of Loop, Interweave, and Kessler Suture Technique using Long Flexor Tendon of Chicken / 대한정형외과연구학회지

OBJECTIVES: The purpose of this study is to compare ultimate tensile load of newly designed loop suture technique, to those of Pulvertaft fishmouth suture technique and Kessler suture technique with core strands. MATERIALS AND METHODS: Eight week-old Habbard chickens were sacrificed to harvest flexor digitorum logus tendon of long toe. They were divided into four groups according to suture technique; interweave suture group, loop suture group, Kessler suture group, and normal control group. Twenty tendons were tested in each group. Comparison of cross-sectional areas between each technique was verified by statistical method and the difference was not statistically significant (p>0.05). Tensile load and deformed length were checked by Instron (Model 1000, Instron Corp, Canton, MA). ANOVA test was used for statistical analysis. RESULTS: Ultimate tensile loads were 22.83+/-7.89 N in interweave suture group, 30.58+/-5.96 N in loop suture group, and 10.83+/-4.47 N in Kessler suture group. These results showed statistically significant differences (p<0.001). The values were 33 % in interweave suture, 44% in loop suture, and 15 % in Kessler's suture respectively. Absorbed energy were 0.48+/-0.32 J in interweave suture group, 0.61+/-0.18 J in loop suture group, and 0.22+/-0.15 J in Kessler suture group, and 1.01+/-0.20 J in normal control group. There were statisti - cally significant differences between each groups (p<0.01). CONCLUSION: The loop suture technique showed better biomechanical properties than interweave or Kessler technique. We think the loop suture technique is a simple and useful method, especially for tendon transfer or tendon graft when tendon length is sufficiently long to make a good tendon overlap.