Hemostasis control in dental extractions in patients receiving oral anticoagulant therapy: an approach with calcium sulfate.

The aim of this study was to evaluate the use of calcium sulfate (CaS) as a hemostatic agent after tooth extraction in patients with anticoagulant drug therapy. A total of 30 patients undergoing anticoagulant therapy (22 women and 8 men) with a mean age of 54.6 years (SD = 9.2 years), needing dental extractions, were selected for this study. They were divided into 2 groups, control (group 1) and test (group 2), in a randomized way. In group 1 patients, the postextraction socket was managed with obliterative suture only. Group 2 patients were treated with CaS placed into the postextraction sockets. All the patients did not interrupt the anticoagulant therapy during the dental treatment. The healing pattern was found to be approximately similar in all treatment groups, showing significant improvement at each consecutive visit. However, a statistically significant difference in the adequate hemostasis was evident between groups 1 and 2 (P = 0.0056). The use of CaS helped to control the bleeding from inside the socket, producing instantly a very good hemostasis. Further studies are necessary to confirm the simplicity, possibilities, and limits of the proposed procedure.

Histologic and histomorphometric results of three bone graft substitutes after sinus augmentation in humans.

The aim of this study was to compare the histological behavior of three bone graft materials placed in human. The comparison was made among Bio-Oss® (BO), Engipore® (EP), and PepGen P-15® (P-15). Five biopsies for each group of biomaterial, retrieved 6 months after sinus lift augmentation, were analyzed. The investigation was carried out using light microscope (LM), scanning electron microscope (SEM) with an energy dispersive spectrometer (EDS), and circularly polarized light microscope (CPLM). Under LM, the amount of newly formed bone was significantly higher in BO than P-15 (P < .05), while the amount of residual graft material was significantly higher in P-15 than BO (P < .05). The extension of marrow spaces was significantly higher in EP than both BO and P-15 (P < .05). SEM-EDS analysis showed a Ca/P ratio of 1.8 for BO, 2.2 for EP, and 1.5 for P-15. Under CPLM, BO showed no significant difference for transverse (18.4 ± 2.7%) and longitudinal (16.3 ± 1.8%) bone collagen fibers (P = .195); EP showed a significant difference between transverse (4 ± 0.7%) and longitudinal (7.6 ± 2.5%) bone collagen fibers (P = .015); finally, P-15 showed no significant difference for transverse (3.8 ± 1.6%) and longitudinal (4.9 ± 1.2%) bone collagen fibers (P = .279). No investigated biomaterial was completely resorbed, but all the residual particles demonstrated a close bone integration to form a hybrid tissue. BO particles appeared perfectly osseointegrated in the trabecular bone. EP showed a tendency to concentrate the bone apposition into the microporosities; P-15 particles appeared bridged by newly formed bone trabeculae.

Effect of margin design on the fracture resistance of Procera all ceram cores: an in vitro study.

AIM: The aim of the present in vitro study is to compare the resistance to fracture under a cyclic load applied to chamfer-edged vs. shoulder-edged Procera All Ceram cores. MATERIALS AND METHODS: An extracted first maxillary premolar was prepared with a 50 degrees chamfer margin using conventional diamond burs, and an impression was taken using a polyvinylsiloxane. The impression was poured ten times using resin to fabricate dies. The same tooth was retrieved and the 50 degrees chamfer was converted into a 90 degrees shoulder by means of an appropriate diamond bur. An impression was taken and ten more resin dies were fabricated. The resin dies were cast using the lost wax technique in order to obtain brass copies. Impressions of each brass die were taken using a polyvinylsiloxane impression material and poured with die stone. The stone dies were sent to a dental laboratory where densely sintered alumina cores 0.4 mm thick were fabricated using a CAD/CAM process. The alumina cores were then cemented on the brass dies and underwent a fracture test with a cyclic load for 24 hours. Fragments were retrieved for fracture characterization using scanning electron microscopy (SEM). RESULTS: The mean values of fracture resistance for the chamfer samples were 406.10 +/- 67.271 N and 643.90 +/- 32.912 N for the shoulder samples. The Student's t-test revealed a statistically significant difference between groups. CONCLUSIONS: The results of this in vitro study indicate a relationship between the cervical thickness of the alumina cores and their fracture resistance. A shoulder margin could improve the biomechanical performance of posterior single crown alumina restorations.