Outcome of 47 consecutive sinus lift operations using aragonitic calcium carbonate associated with autologous platelet-rich plasma: clinical, histologic, and histomorphometrical evaluations.

BACKGROUND: The reconstruction of the maxillary bone frequently represents a real challenge for maxillofacial surgeons especially regarding the best choice of a suitable material to produce the required bone augmentation. AIM: In this study, we summarize our clinical experience on 47 sinus lifts with lateral approach using a mixture of aragonitic calcium carbonate and autologous platelet-rich plasma compared with that of a previous published study in which bovine bone (LADDEC) and autologous bone were used in 50 sinus lift operations (Br J Oral Maxillofac Surg 2005;43:309-313). MATERIALS AND METHODS: We subjected 34 patients to sinus lift operation, for a total of 47 sinus lifts, using natural coral as osteoconductive material. This material, combined with autologous platelet-rich plasma, was placed onto the maxillary sinus floor, after carefully lifting the endosteum. Cases were clinically, radiographically, and histologically analyzed. Histomorphometrical analysis, tests of microhardness, and x-ray microanalysis were conducted comparing the various sample to controls obtained from the same patients. RESULTS AND CONCLUSIONS: Histomorphometrical analysis, microhardness test, and x-ray microanalysis demonstrated that the newly formed bone showed morphologic and structural characteristics that were similar for all the grafting materials compared (bovine bone, autologous bone, and coral). Although all the grafting materials did yield good results of maturation of the newly formed bone, best results were achieved using autologous bone.

Iron depletion before HCV antiviral therapy: a pilot, randomized, controlled trial.

It is not known whether iron depletion before pegylated IFN or combination treatment improves sustained virological response (SVR) rate in patients with chronic hepatitis C, despite its use in clinical practice in this setting. We aimed to investigate whether blood letting improves the efficacy (SVR) and tolerability of PEG-IFNalpha2b + Ribavirin in chronic hepatitis C patients. Patients with chronic hepatitis C and ferritin >100 ng/mL were randomized to: (1) repeated phlebotomies to obtain a ferritin level <50 ng/mL followed by pegylated-Interferon alpha2b + ribavirin (active arm); or (2) pegylated-Interferon alpha2b + ribavirin (control arm). Primary endpoint was SVR rate, secondary endpoint was frequency of clinical and laboratory grade 3-4 adverse events. Thirty-three patients were enrolled in the study (19 in active arm, 14 in control arm). The 19 patients in the active arm underwent a median of 5 phlebotomies (range: 1-9) to achieve the targeted ferritin (<50 ng/mL). Phlebotomies significantly reduced ferritin, iron, transferrin saturation, aspartate aminotransferase, alanine aminotransferase, and hemoglobin levels. Platelet count significantly increased, whereas HCV-RNA levels remained unchanged. After antiviral therapy overall SVR was 31.6% in active arm and 21.4% in control arm (P = 0.698). Considering only the 18 patients who were naive to antiviral therapy, SVR was 60% in active arm versus 25% in control arm (P = 0.188). Tolerability, drug dose reduction or withdrawal were similar in the two arms. In conclusion phlebotomies do not increase the overall efficacy of antiviral therapy. However, the strong trend to higher SVR in naive patients undergoing phlebotomies warrants further investigation.

Platelet gel supplementation in long bone nonunions treated by external fixation.

OBJECTIVE: The aim of the present study was to evaluate the use of previously frozen, thawed platelet gel supplementation to accelerate the healing of long bone nonunions treated by external fixation. DESIGN: Prospective case series with historical controls. SETTING: University Hospital. PATIENTS: Twenty patients affected by tibial, humeral, or forearm atrophic nonunions were treated by percutaneous stabilization with unilateral external fixators and injection of autologous platelet gel. The healing time was compared to the result obtained in a historical control group treated without platelet gel supplementation. MAIN OUTCOME MEASUREMENTS: Consolidation rate and radiographic healing time of nonunions in the 2 groups were assessed by independent blinded observers. The nonunion was judged to be healed when bridging callus formation on both radiographic views was observed on at least 3 of 4 cortices. RESULTS: The healing rate of nonunion was 90% (18/20) in platelet gel cases and 85% (17/20) in controls, respectively (P = 0.633). The mean time until radiographic consolidation in nonunions supplemented with platelet gel (147 +/- 63 days) was not different to the result in the control group (153 +/- 61 days; P = 0.784). Analyzing the mean healing time for separate segments, no differences were noted between study and control group-that is, tibia: 112 +/- 43 and 130 +/- 5 days, respectively (P = 0.382); humerus, 225 +/- 36 and 202 +/- 70 days, respectively (P = 0.530). CONCLUSION: The present study failed to show the clinical usefulness of isolated percutaneous platelet gel supplementation in long bone nonunions treated by external fixation; however, caution should be exercised in interpreting this result because the actual numbers are small and the statistical power is limited.

Thrombin-activated platelets induce proliferation of human skin fibroblasts by stimulating autocrine production of insulin-like growth factor-1.

Platelet components have found successful clinical utilization to initiate or to accelerate tissue-repair mechanisms. However, the molecular pathways by which platelet factors contribute to tissue regeneration have not been fully elucidated. We have studied the effect of thrombin-activated platelets (TAPs) on cell growth in vivo and in cultured cell systems. Application of TAPs to ulcerative skin lesions of diabetic patients induced local activation of ERK1/2 and Akt/PKB. Moreover, when applied to cultured human skin fibroblasts, TAPs promoted cell growth and DNA synthesis and activated platelet-derived growth factor (PDGF) and insulin-like growth factor (IGF)-1 receptor tyrosine kinases. PDGF was released by TAPs and rapidly achieved a plateau. At variance, the release of IGF-1 was mainly provided by the TAPs-stimulated fibroblasts and progressively increased up to 48 h. The PDGF-R blocker Ag1296 reduced the activation of Akt/PKB and, at a lesser extent, of ERK1/2. Conversely, inhibition of IGF-1 signaling by Ag1024 and expression of a dominant-negative IGF-1R mutant selectively reduced the stimulation of ERK1/2 by TAPs and fibroblast-released factors, with minor changes of Akt/PKB activity. Thus, platelet factors promote fibroblast growth by acutely activating Akt/PKB and ERK1/2. Sustained activation of ERK1/2, however, requires autocrine production of IGF-1 by TAPs-stimulated fibroblasts.

Use of autologous platelet-rich plasma (PRP) in periodontal defect treatment after extraction of impacted mandibular third molars.

PURPOSE: The extraction of mesioangular impacted third molars may cause multiple periodontal defects at the distal root of the second molar. Platelet-rich plasma (PRP) is a material containing many autologous growth factors that may be used in repairing and preventing periodontal complications at the distal root of the second molar adjacent to the extracted third molar. PATIENTS AND METHODS: We analyzed the effects of autologous PRP on periodontal tissues after extraction of the third molar in 18 young patients (age, 21-26 years). Inclusion criteria were the presence of a pocket distal to the mandibular second molar with a probing depth>or=7.5 mm and a probing attachment level>or=6 mm. RESULTS: We observed, at 12 weeks after surgery, a notable reduction in the probing depth and an improvement in the probing attachment level in those cases treated with PRP compared with the controls, as well as formation of new bone tissue in the bone defect. CONCLUSION: We showed that PRP is effective in inducing and accelerating bone regeneration for the treatment of periodontal defects at the distal root of the mandibular second molar after surgical extraction of a mesioangular, deeply impacted mandibular third molar.