Patterns of cell death and cell cycle profiles of cultured WEHI 13 var fibroblasts exposed to eluates of composite resins used for direct and indirect restorations

Previous studies have shown that in vitro exposure to single compounds released from composite resins may induce cell death. In the present study the effects of eluates from commercially available composite resins used for direct or indirect restorations were evaluated on the cell cycle progression and type of cell death of cultured WEHI 13 var fibroblasts. Cells exposed to eluates of the materials were assessed for cytotoxicity by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay for cell death, for cell cycle profiles by flow cytometry, for caspase-3 biochemically and by immunocytochemistry, and for morphological changes by fluorescence microscopy with acridine orange. The direct composite resin eluates induced extensive apoptosis, followed by secondary necrosis. This was accompanied by cell enlargement, micromultinucleation, chromatin disintegration, cell cycle arrest at different phases, and caspase-3 activation. The composites for indirect restorations were much less cytotoxic at all biological end-points investigated. The findings suggest that composite resins used for direct and indirect dental restorations differ in their cytotoxic potential and their ability to affect basic cellular functions. This underlines the impact of improved polymerization with respect to their biologic behavior.     

磁性纳米粒子复合支架及外加磁场影响成骨作用的研究进展

磁性纳米粒子（MNP）具有独特的磁响应性、生物相容性,在作为生物材料时可通过其内在的微小磁场促进成骨分化。掺入MNP的磁性复合支架保留了MNP的超顺磁性,具有良好的物理机械性能以及生物学性能,在体内外均取得良好的成骨效果。外加磁场可通过影响细胞代谢行为促进骨组织修复,与MNP复合支架结合可起到协同促进骨组织修复再生的作用,在骨组织工程领域的应用潜力巨大。本文就MNP复合支架的性能、MNP复合支架和磁场的成骨作用研究进展作一综述,为MNP复合支架进一步研究和临床应用提供参考。     

高压氧在下肢复合伤中的应用

目的观察下肢复合伤中应用高压氧的效果。方法 82例下肢开放性复合伤患者随机分为两组,均采用手术、清创、皮瓣转移,术后抗生素预防感染的常规治疗,观察组42例在常规治疗基础上加用高压氧治疗,共进行20 d。观察组治疗前后两组患者肌肉组织恢复情况、皮瓣转移存活率和骨折的愈合情况。结果观察组在治疗后局部肿胀消退,无疼痛或轻度压痛患者27例(64.3%),对照组在治疗后局部肿胀消退,无疼痛或轻度压痛患者13例(32.5%),观察组明显优于对照组(P<0.05)。观察组有21例患者行皮瓣转移,存活20例(95.2%),对照组有18例患者行皮瓣转移,存活15例(83.3%),观察组皮瓣转移存活率明显高于对照组(P<0.05)。平均随访12个月,观察组骨折平均愈合时间为4个月,愈合41例,愈合率97.6%;对照组骨折平均愈合时间为6个月,愈合37例,愈合率92.5%.观察组在愈合时间方面明显少于对照组(P<0.05),观察组骨折愈合率明显高于对照组(P<0.05)。结论高压氧治疗可以减轻下肢复合伤炎性反应、提高皮瓣转移存活率和加快骨折愈合。     

复合保温措施对剖宫产产妇围术期低体温和寒战发生的影响

目的 探讨复合保温措施防止剖宫产产妇围术期低体温和寒战发生的作用,为建立围术期患者有效的保温模式提供实验依据.方法 选择健康初产妇120例,将其随机分为对照组（62例）和观察组（58例）,对照组在手术恒温床上施行剖宫产术并采取常规保温方式,观察组在此基础上采取调整手术室温度,静脉输注液、冲洗液和纱布预温,使用强制充气加温毯以及减少身体裸露面积等的复合保温措施;监测产妇入室至手术结束的口腔温度和寒战状况,并进行统计学比较.结果 对照组产妇手术20 min、手术40 min和手术结束时的体温均低于入室时（P＜0.01）,观察组产妇手术20 min、手术40 min和手术结束时的体温与入室时比较,差异无统计学意义（P＞0.05）,且均分别高于同时间点的对照组（P＜0.05）;对照组的低体温发生率显著高于观察组（51.6％ vs 3.4％,P＜0.01）;两组产妇均未发生3、4级寒战,对照组的1、2级寒战发生率显著高于观察组（22.6％vs 3.4％,P＜0.01）.结论 复合保温措施能有效维持剖宫产产妇围术期体温恒定,预防术中低体温和寒战的发生.     

The Influence of Irrigation during the Finishing and Polishing of Composite Resin Restorations—A Systematic Review of In Vitro Studies

The surface smoothness of composite restorations affects not only their esthetic appearance but also other properties. Thus, rough surfaces can lead to staining, plaque accumulation, gingival irritation, recurrent caries, abrasiveness, wear kinetics, and tactile perception by the patient. The aim of this study was to evaluate the influence of irrigation during the finishing and polishing of composite resin restorations. A systematic search of the PubMed, Cochrane Library, EMBASE, Web of Science, and Clinical Trials databases was conducted. Papers published up to 11 February 2021 were considered. The quality of each study was assessed using the modified Consolidated Standards of Reporting Trials checklist for reporting in vitro studies on dental materials. No clinical studies were identified. Six in vitro studies were included, reporting changes in physical and esthetic properties. After performing a methodological quality assessment of the studies, some limitations were identified, the main limitation being the heterogeneous methodology across studies. The evidence resulting from this systematic review did not favor either wet or dry finishing/polishing procedures. There is a clear need for well-designed studies focusing on the comparison of dry/wet finishing/polishing with standard protocols to evaluate the differences among different materials and methods.     

Molecular Interactions between Saliva and Dental Composites Resins: A Way Forward

Dentin and enamel loss related to trauma or especially caries is one of the most common pathological issues in dentistry that requires restoration of the teeth by using materials with appropriate properties. The composite resins represent dental materials with significant importance in today’s dentistry, presenting important qualities, including their mechanical behavior and excellent aesthetics. This paper focuses on the saliva interactions with these materials and on their biocompatibility, which is continuously improved in the new generations of resin-based composites. Starting from the elements involved on the molecular landscape of the dental caries process, the paper presents certain strategies for obtaining more advanced new dental composite resins, as follows: suppression of oral biofilm acids formation, promotion of remineralization process, counteraction of the proteolytic attack, and avoidance of cytotoxic effects; the relation between dental composite resins and salivary oxidative stress biomarkers is also presented in this context.     

复合补片和生物补片治疗食管裂孔疝的疗效对比研究

目的:对比应用复合补片和生物补片治疗反流性食管炎和食管裂孔疝的疗效。方法:21例应用Crurasoft誖复合补片组及20例应用BiodesignTM Surgisis誖生物补片组修补食管裂孔疝病人,对比分析术后复发率和补片相关并发症发生的差异。结果:两组病人一般情况、食管裂孔长径和手术时间等方面无统计学差异。应用复合补片和生物补片均能使术前反流性食管炎的症状显著缓解。复合补片组和生物补片组围手术期并发症发生率分别为9.5%和30.0%,两组间无统计学差异。术后6个月随访裂孔疝复发率均为0。复合补片组和生物补片组长期随访平均时间分别为(16.3±8.9)个月和(17.3±6.8)个月,解剖性复发率分别为4.8%和5.0%,无统计学差异。两组病人均未发生食管侵蚀的并发症。复合补片组病人术后吞咽困难发生率高于生物补片组(38.1%比20..0%),但无统计学差异。结论:应用新一代小肠黏膜下基质补片和复合补片修补食管裂孔疝后疗效满意,复发率低,补片相关的严重并发症发生率差异无统计学意义。     

Free thoracodorsal,perforator-scapular flap based on the angular artery (TDAP-Scap-aa): Clinical experiences and description of a novel technique for single flap reconstruction of extensive oromandibular defects

PurposeThe reconstruction of oromandibular defects can be challenging, particularly when considerable amounts of bone and soft tissues are lost. In such cases, the use of a single flap may be unsatisfactory and a concomitant free flap is needed. Here we present a chimeric, thoracodorsal perforator-scapular free flap based on the angular artery of the subscapular system (TDAP-Scap-aa) as an alternative technique for single flap reconstruction of extensive oromandibular defects.Materials and methodsThe authors studied patients who underwent reconstructions of extensive oromandibular defects with a TDAP-Scap-aa free flap. The operative technique and the clinical experiences are described. Postoperatively, surgical complications were classified with the Clavien-Dindo Classification.ResultsFive male patients (59.4 ± 8.8 years) were treated with the TDAP-Scap-aa. Average sizes for harvested hard and soft tissue components, which are both included in the flap and completely independently from each other, were 10.4 ± 1.5 cm of bone length, 2.6 ± 0.3 cm of bone height, 11.6 ± 4.8 cm of skin paddle length and 8.4 ± 1.7 cm of skin paddle width. The overall mean operation time (cut-suture) was 14.6 ± 0.9 h. The postoperative follow-up was 6 months. No complications requiring surgical treatment as well as donor site nerve damages were observed.ConclusionsIn comparison to other double free flaps, the TDAP-Scap-aa offers several advantages such as higher amounts of hard and soft tissues without prolonged operation times, and provides satisfying aesthetic outcomes and little donor site morbidity due to the preservation of muscle and nerve structures. Therefore, the TDAP-Scap-aa constitutes a clinically reliable alternative in extensive oromandibular defect reconstruction.     

Exothermic properties of plaster–synthetic composite casts

Purpose

Plaster casts can cause burns. Synthetic casts do not. Composite plaster–synthetic casts have not been thoroughly evaluated. This study analyzed the temperature from plaster casts compared with composite casts in a variety of in vitro conditions that would simulate clinical practice.

Methods

A Pyrex cylinder filled with constant body temperature circulating water simulated a human extremity. Circumferential casts, of either plaster or composite construction (plaster inner layer with outer synthetic layer), were applied to the model. Peak temperatures generated by the exothermic reactions were studied relative to the following variables: dip water temperature (24 °C versus 40 °C), cast thickness (16, 30, and 34 ply), and delayed (5-min) versus immediate application of the synthetic outer layers. Peak temperatures from the all-plaster casts were compared with the composite casts of the same thickness. Finally, the relative cast strength was determined.

Results

Potentially dangerous high temperatures were measured only when 40 °C dip water was used or when thick (30- or 34-ply) casts were made. Cast strength increased with increasing cast thickness. However, the presence of synthetics in the composite casts layers did not increase cast strength in every case.

Conclusion

When applying composite casts, the outer synthetic layers should be applied several minutes after the plaster to minimize temperature rise. Composite casts do not routinely generate peak temperatures higher than plaster casts of similar thickness. Because the skin of children and the elderly is more temperature-sensitive than average adult skin, extra care should be taken to limit the exothermic reaction when casting children and the elderly: clean, room temperature dip water, minimal required cast thickness, avoidance of insulating pillows/blankets while the cast is drying.