Tomographic and histomorphometric evaluation of socket healing after tooth extraction using leukocyte- and platelet-rich fibrin: A randomized,single-blind,controlled clinical trial

The use of platelet concentrate in alveolar ridge preservation has been broadly studied. However, no randomized clinical trials with histomorphometric analysis and low risk of bias are available in the literature. We conducted a prospective, single-blind, parallel, randomized, controlled clinical trial to evaluate the efficacy of leukocyte- and platelet-rich fibrin (L-PRF) in socket preservation after tooth extraction. Additionally, the effect of L-PRF on bone formation was analyzed histologically using bone biopsy specimens obtained during implant placement.A total of 48 subjects who underwent a non-molar tooth extraction were randomly assigned to the L-PRF group (n = 24) or the control group (n = 24). Cone-beam computed tomographies were performed immediately after tooth extraction and at 3 months after tooth extraction, prior to implant surgery. A significant difference in bone resorption was registered 1 mm below the crest: 0.93 ± 0.9 mm for the L-PRF group and 2.27 ± 1.2 mm for the control group (p = 0.0001). Histomorphometric analysis showed a higher percentage of new bone formation in the L-PRF group compared with the control group. The values were 55.96 ± 11.97% and 39.69 ± 11.13%, respectively (p = 0.00001). These findings indicate that the administration of L-PRF should always be considered when socket preservation is planned (Clinicaltrials.gov NCT03408418).     

Efficacy of cyanoacrylate tissue adhesive in the management of corneal thinning and perforation due to microbial keratitis

PurposeReport the efficacy of cyanoacrylate tissue adhesive (CTA) application in the management of corneal thinning and perforations associated with microbial keratitis.MethodsA retrospective review of consecutive patients who underwent CTA application for corneal thinning and perforation secondary to microbiologically proven infectious keratitis between 2001 and 2018 at a single center. We defined successful CTA application as an intact globe without tectonic surgical intervention.ResultsThe cohort included 67 patients, and 37 presented with corneal perforation while 30 had corneal thinning. The perforation/thinning was central/paracentral in 43 eyes and peripheral in 23 eyes. The underlying infectious etiologies were monomicrobial in 42 cases (35 bacterial, 3 fungal, 2 viral, and 2 acanthamoeba cases) and polymicrobial in 25 cases (22 polybacterial cases and 3 cases with a combination of Gram positive bacteria and fungus). The median duration of glue retention was 29 days. The CTA success rate was 73%, 64%, and 44% at 10, 30, and 180 days, respectively. CTA application appears more successful in monomicrobial (vs. polymicrobial) and Gram positive bacterial (vs. Gram negative) keratitis but the differences are statistically non-significant. The location of perforation/thinning and the use of topical corticosteroid were not associated with CTA failure.ConclusionCTA was moderately effective in restoring globe integrity in severe corneal thinning and perforation secondary to microbial keratitis in the short term. However the majority of patients require tectonic surgical intervention within 6 months. CTA application success is not significantly associated with the location of thinning/perforation or the use of topical corticosteroid.     

Antimicrobial Activity and Biocompatibility of Antibiotic-Loaded Chitosan Hydrogels as a Potential Scaffold in Regenerative Endodontic Treatment

IntroductionThe objective of this study was to determine the effectiveness of several antibiotic-loaded hydrogel scaffolds against Enterococcus faecalis, as well as their ability to stimulate proliferation and mineralization of dental pulp stem cells.MethodsFibrin (Fg) or chitosan-fibrin hydrogels (Ch) were prepared using 12.5 mg/mL fibrinogen and 0.4% (w/v) chitosan. Triple antibiotics, clindamycin-modified triple antibiotic paste, or double antibiotics were loaded in gels (1 mg/mL). Antibacterial effect against E. faecalis biofilm was determined by using colony-forming units (CFUs) and confocal laser scanning microscope (CLSM). Cell viability and morphology were determined by loading cells into different gels at 7 and 14 days using the water-soluble tetrazolium salt-1 cell viability assay and Live & Dead cell analysis. Mineralization was detected by using alkaline phosphatase and alizarin red staining activity.ResultsAntibiotic-loaded Fg gel and Ch gel alone without antibiotics resulted in a significant reduction in CFUs compared with the positive control (P < .05). When antibiotics were loaded in Ch gel, there were no CFUs detected in any groups (P < .05). CLSM images showed dense red areas with mostly dead bacteria on the dentin surface in antibiotic-loaded Ch groups, which showed significantly less live bacteria compared with the other groups (P < .05). Triple antibiotic-loaded Fg and Ch gels resulted in a dramatic decrease in the mineralized nodule formation compared with all other gel groups (P < .05). Ch hydrogels resulted in round cell morphology up to 7 days. Ch alone or with double antibiotic paste showed more cell spreading with spindle-shaped morphology at 14 days and higher alkaline phosphatase activity compared with other antibiotic-loaded Ch groups (P > .05).ConclusionsDouble antibiotic-loaded Ch gel appears to enhance the antibacterial properties while maintaining higher cell viability, cell spreading, and mineralization activity, compared with all the other scaffolds investigated.     

Heterologous fibrin sealant potentiates axonal regeneration after peripheral nerve injury with reduction in the number of suture points

The use of suture associated with heterologous fibrin sealant has been highlighted for reconstruction after peripheral nerve injury, having the advantage of being safe for clinical use. In this study we compared the use of this sealant associated with reduced number of stitches with conventional suture after ischiatic nerve injury. 36 Wistar rats were divided into 4 groups: Control (C), Denervated (D), ischiatic nerve neurotmesis (6 mm gap); Suture (S), epineural anastomosis after 7 days from neurotmesis, Suture + Fibrin Sealant (SFS), anastomosis with only one suture point associated with Fibrin Sealant. Catwalk, electromyography, ischiatic and tibial nerve, soleus muscle morphological and morphometric analyses were performed. The amplitude and latency values of the Suture and Suture + Fibrin Sealant groups were similar and indicative of nerve regeneration.The ischiatic nerve morphometric analysis in the Suture + Fibrin Sealant showed superior values related to axons and nerve fibers area and diameter when compared to Suture group. In the Suture and Suture + Fibrin Sealant groups, there was an increase in muscle weight and in fast fibers frequency, it was a decrease in the percentage of collagen compared to group Denervated and in the neuromuscular junctions, the synaptic boutons were reestablished.The results suggest a protective effect at the lesion site caused by the fibrin sealant use. The stitches reduction minimizes the trauma caused by the needle and it accelerates the surgical practice. So the heterologous fibrin sealant use in nerve reconstruction should be considered.     

富血小板纤维蛋白修复大鼠骨外露创面的实验研究

目的探讨富血小板纤维蛋白(PRF)治疗大鼠骨外露创面的疗效。方法取10~12周龄,250~300 g的雄性SD大鼠24只,应用随机数字表法将其分为3组,每组8只。将所有SD大鼠前头盖骨区域1.5 cm×1.5 cm皮肤全层切除及并去除颅骨表面的骨膜。PRF组创面覆盖PRF;脂肪移植组创面覆盖等量脂肪颗粒;对照组创面覆盖等量生理盐水。分别于第4、7和11天对创面换药。使用Image J软件对骨外露面积进行量化评估。应用HE染色和马松三色染色评估创面新生血管和胶原沉积情况。酶联免疫吸附实验检测创面肉芽组织生长因子水平。组间比较采用随机资料单因素方差分析。结果术后第4天时,PRF组大鼠骨外露比例为57.99%±11.29%;脂肪移植组骨外露比例为45.92%±9.55%;对照组骨外露比例为77.73%±5.57%。第7天时,PRF组大鼠骨外露比例为4.29%±2.28%;脂肪移植组骨外露比例为29.52%±6.33%;对照组骨外露比例为36.90%±8.43%。第11天时,仅PRF组的骨外露创面完全被肉芽组织覆盖,脂肪移植组及对照组均存在不同程度的骨外露,分别为10.15%±1.49%和21.69%±2.40%。PRF组在各时间点创面骨外露面积均显著低于对照组,差异具有统计学意义(P<0.01)。在第7天和第11天时,PRF组的骨外露比例显著低于脂肪移植组,但是在第4天时,脂肪移植组的骨外露比例却低于PRF组,差异均具有统计学意义(P<0.001)。第11天时,HE染色结果显示PRF组的新生微血管密度为(10.37%±0.49%)显著高于脂肪移植组(4.86%±0.83%)和对照组(2.91%±0.31%)(P<0.05),马松三色染色结果显示PRF组的胶原纤维最丰富。酶联免疫吸附实验结果提示第11天时PRF组的生长因子水平均明显升高,与脂肪移植组和对照组比较,差异均具有统计学意义(P<0.05)。结论PRF作为一种取材方便的治疗手段,对修复创面具有良好的疗效,可加快骨外露创面愈合。     

喉癌患者PAC-1、CD62P表达与临床病理特征和复发的关系

目的探讨喉癌患者血小板表面血小板膜糖蛋白Ⅱb/Ⅲa纤维蛋白原受体(PAC-1)、血小板P-选择素(CD62P)阳性表达率以及与患者临床病理特征和复发的关系。方法选取2014年1月~2015年12月间在我院耳鼻喉科手术治疗的116例喉癌患者,随访≥2年,并选取同期在我院体检的健康人群60例为对照组,采用流式细胞仪检测法检测外周血PAC-1和CD62P阳性率,并分析与临床病理特征、复发的关系。结果喉癌患者PAC-1和CD62P阳性表达率分别为(17.82±1.76)%和(22.87±3.13)%,明显高于健康人群(P<0.05);而且在喉癌患者PAC-1表达和CD62P表达呈正相关性(r=0.238,P<0.05)。T3-T4分期或N2-N3分期患者PAC-1和CD62P阳性表达率高于T1-T2分期或N0-N1分期患者(P<0.05)。另外远处转移组PAC-1和CD62P阳性表达率高于未发生转移组(P<0.05);随访期间有24例患者复发,复发率为20.69%。复发喉癌患者PAC-1、CD62P阳性表达率分别为(17.02±0.85)%和(21.84±1.17)%,明显高于未复发的喉癌患者(P<0.05)。经Logistics回归分析,PAC-1和CD62P是喉癌患者复发的独立危险因素(P<0.05)。结论PAC-1和CD62P阳性表达率与喉癌患者T分期、淋巴结转移和远处转移密切相关,同时可作为喉癌局部复发、区域淋巴结转移、远处转移的预测指标。     

Comparison between self‐assembling peptide nanofiber scaffold (SAPNS) and fibrin sealant in neurosurgical hemostasis

RADA16‐I is a synthetic type I self‐assembling peptide nanofiber scaffold (SAPNS) which may serve as a novel biocompatible hemostatic agent. Its application in neurosurgical hemostasis, however, has not been explored. Although RADA16‐I is nontoxic and nonimmunogenic, its intrinsic acidity may potentially provoke inflammation in the surgically injured brain. We conducted an animal study to compare RADA16‐I with fibrin sealant, a commonly used agent, with the hypothesis that the former would be a comparable alternative. Using a standardized surgical brain injury model, 30 Sprague–Dawley rats were randomized into three treatment groups: RADA16‐I, fibrin sealant or gelatin sponge (control). Animals were sacrificed on day 3 and 42. Astrocytic and microglial infiltrations within the cerebral parenchyma adjacent to the operative site were significantly lower in the RADA16‐I and fibrin sealant groups than control. RADA16‐I did not cause more cellular inflammatory response despite its acidity when compared with fibrin sealant. Immunohistochemical studies showed infiltration by astrocytes and microglia into the fibrin sealant and RADA16‐I grafts, suggesting their potential uses as tissue scaffolds. RADA16‐I is a promising candidate for further translational and clinical studies that focus on its applications as a safe and effective hemostat, proregenerative nanofiber scaffold as well as drug and cell carrier.