Luciano Tavares Ângelo Cintra

Tissue Reaction to a Triantibiotic Paste Used for Endodontic Tissue Self-regeneration of Nonvital Immature Permanent Teeth

INTRODUCTION The endodontic regenerative procedure (ERP), which is an alternative to calcium hydroxide-induced apexification, involves the use of a triple antibiotic paste (TAP) as a dressing material. The aim of this study was to evaluate the response of rat subcutaneous tissue to implanted polyethylene tubes that were filled with TAP or calcium hydroxide. METHODS Thirty rats received 2 individual implants of polyethylene tubes filled with TAP or calcium hydroxide paste (CHP) and another empty tube as a control. Thirty additional rats received 2 individual implants consisting of polyethylene tubes filled with dressing material carriers (macrogol and propylene glycol) and a sham procedure. After 7, 15, 30, 60, and 90 days, 12 animals were euthanized, and the tubes and surrounding tissue were removed and processed for histology by using glycol methacrylate and stained with hematoxylin and eosin. The histological score ranged from 0 to 3 depending on the content of inflammatory cells; the fibrous capsule was considered thin or thick, and necrosis and calcification were recorded as present or absent. The results were analyzed using the Kruskal-Wallis test. RESULTS Both dressing materials induced moderate reactions at 7 and 15 days. These reactions were similar to the control (P > .05) and reduced in intensity (to mild) from day 30 onward (P > .05). The carriers did not interfere with the reaction of the dressing materials. CONCLUSIONS TAP and CHP were biocompatible over the different experimental periods examined.

Evaluation of alveolar socket response to Angelus MTA and experimental light-cure MTA

OBJECTIVE The aim of this study was to evaluate the rat alveolar socket response to implanted polyethylene tubes filled with a light-cured MTA or Angelus MTA. STUDY DESIGN Fifty-seven Wistar rats received an implant filled with one of the materials in the dental socket of the right central incisor. After 30, 60, and 90 days, animals were killed, and the right hemimaxillas were removed and processed to be analyzed on light microscopy. After embedding in paraffin, 6-μm-thick sections were obtained and stained with hematoxylin and eosin. Qualitative and quantitative analyses of the reaction were performed. RESULTS It was observed that the light-cured MTA presented a similar response compared with Angelus MTA, characterized by the reduction of the chronic inflammatory response and organization of the alveolar bone close to the materials, especially at the 90th day of observation. CONCLUSIONS It was concluded that both materials were well accepted by the alveolar tissue of rats, with the formation of mineralized tissue close to the materials.

Osseointegration of Ti-30Ta Implants without Primary Stability: Effect of Tranexamic Acid

A large clot formed between the inside of the bony wall of the extraction socket and the immediate implant surface may have premature breakdown . Tranexamic acid (TXA) is fibrinolysis inhibitor and an analog of the amino acid lysine. In this paper the influence of tranexamic acid on the osseointegration of Ti-30Ta implants without primary stability was investigated. Were fabricated 32 implants of CP Titanium Grade 4 and 32 implants of Ti-30Ta alloy with dimensions of 2.1 x 2.8mm Ø. Bone defects of 2.5x3.2 mm Ø were created in right tibia of 64 Wistar male-rats using a small round bur. They were divided (n=16) into: Group I (CP-Ti machined implant), Group II (CP-Ti machined implant/ tranexamic acid), Group III (Ti-30Ta implant) and Group IV (Ti-30Ta implant/ tranexamic acid). The surgical defects of the Group II and Group IV were bathed with 20 ml of the tranexamic acid solution. The animals were euthanized at 45 days postoperative. In the right tibia of half each group (8 animals/8 tibiae) the maximum torque value necessary for manual removal of each implant was measured in Newton centimeters (Ncm). The right tibia of other half each group was subjected to non-decalcified histology processing (Stevenels blue/Alizarin red). Data were analyzed statistically (Kruskal-Wallis Analyses) and demonstrated significant differences (P<0.05) among groups. The values of group I were significantly lower than group III and IV, but without significant difference than group II both removal torque and peri-implant bone healing. The results suggest that: a) peri-implant bone formation occurred more rapidly around the Ti-30Ta implant; b) tranexamic acid favored the stabilization of blood clot and bone formation around Ti-30Ta implants and not influenced bone formation around Ti-CP implants.