低强度超声对放射线损伤的犬下颌骨微血管修复作用的实验研究

目的:探讨低强度超声对放疗后犬下颌骨微血管的修复作用,为临床防治放射性骨坏死提供实验理论依据.方法:建立下颌骨放射线损伤的动物模型,免疫荧光观察实验Ⅰ组、实验Ⅱ组与对照组CD34的表达.运用低强度超声对其进行治疗,并通过微血管密度(MVD)检测实验Ⅰ组(超声治疗10d,20d,30d)、实验Ⅱ组(未用低强度超声治疗组)与对照组的微血管密度,所得数据进行统计学分析.结果:成功的建立了放射线损伤的动物模型;免疫荧光染色显示对照组CD34呈强阳性表达,实验Ⅰ组呈阳性表达,实验Ⅱ组呈弱阳性表达;MVD检测结果显示实验Ⅱ组呈弱阳性表达,实验Ⅰ组的微血管密度为:10d组(4.04±0.77),20d组(6.22±0.65),30d组(7.13±0.43);实验Ⅱ组为3.85±0.89;与对照组为7.41±0.45.统计结果显示各组之间的差异具有显著性的意义(P＜0.05).结论:低强度超声对放射线损伤后骨组织内的微血管具有较好的修复作用.     

低强度脉冲超声促进钛种植体骨结合的实验研究

目的 建立种植体植入动物模型,研究低强度脉冲超声(low intensity pulsed ultrasound,LIPUS)对种植体骨结合的促进作用.方法 选用雌性SD大鼠24只,每只大鼠双侧胫骨干骺端内侧植入螺纹状钛种植体.植入术后第2天对右侧胫骨种植体周围进行LIPUS刺激作为实验侧,每日20 min,左侧胫骨种植体植入部位不刺激作为自身对照侧.超声刺激后第4、8、12 周分批处死动物,每批8只,获取双侧胫骨标本.采用X线片、显微CT、组织切片等观察LIPUS对种植体骨结合的作用.结果 3个时间点种植体与骨组织之间均形成了不同程度的骨结合.显微CT组织形态计量学分析结果显示,种植体周骨结合率在实验侧第4、8、12周分别为(45.708±3.316)%、(46.231±1.954)%、(46.807±1.451)%,在对照侧分别为(43.021±3.558)%、(44.272±3.023)%、(44.894±4.215)%,第4周时差异具有统计学意义(P<0.05).种植体周骨体积分数在第4、8周,种植体周骨小梁厚度及第8周、第12周各向异性程度,实验侧均高于自身对照侧,差异有统计学意义(P<0.05).组织学切片可见实验侧种植体周新生骨组织厚度明显大于自身对照侧,骨结合量更多.结论 LIPUS可以促进种植体周围骨组织的愈合,加快种植体骨结合,并能促进骨小梁早期呈一定方向改建.

Abstract：

Objective To establish an animal model of titanium implant and to investigate the effects of low intensity pulsed ultrasound(LIPUS)on the implant osseointegration. Methods Twenty-four female Sprague Dawley(SD)rats were used. Titanium implants were inserted into tibia metaphysis bilaterally in each SD rat. Since the second day following implant surgery, LIPUS stimulation were carried out around the implant on the right side for 20 minutes per day, and implants on the left side remain untouched as self-control. Eight rats were sacrificed and tibiae specimens were harvested on the end of the 4th, 8th, and 12th week respectively. X-ray picture,micro-CT analysis and histological sections were performed to evaluate the effects of LIPUS on the implant osseointegration. Results Osseointegration at the interface between the implant and bone tissue was observed bilaterally. In the micro-CT histomorphometry analysis, the percentage of osseointegration(%OI)of experiment side were (45.708±3.316)%, (46.231±1.954)%, and (46.807±1.451)% on the end of the 4th, 8th, and 12th week. Meanwhile, the %OI of control side were (43.021±3.558)%, (44.272±3.023)%, and (44.894±4.215)% respectively. The %OI on the 4th weekend, bone volume ratio(BV/TV)on the 4th and 8th weekend,trabecular thickness(Tb. Th)and degree of anisotropy(DA)on the 8th and 12th weekend of the experiment side tibia were significantly greater than those on the control side(P<0.05). The histological examination showed that the thickness of new bone around the implant and the bone-implant contact area was obviously greater in the LIPUS treated side compared to the control side.Conclusions The LIPUS therapy may accelerate the bone healing and osseointegration at the interface between titanium implant and bone, and promote remodeling of bone trabecula on the early stage.     

低强度超声治疗颌骨放射性骨坏死的研究进展

颌骨放射性骨坏死是头颈部恶性肿瘤患者放疗后常见的严重并发症, 迄今尚无满意的治疗方法。低强度超声作为一种新的非侵入性疗法正逐渐引起人们的关注。本文就其治疗颌骨放射性骨坏死的研究现状做一概述。     

99mTc-MDP骨显像观察低强度脉冲超声促进犬下颌骨牵张新生骨痂成熟的作用

目的:应用99mTc-MDP骨显像来观察低强度脉冲超声对犬下颌牵张新生骨痂的促成熟作用.方法:利用内置式牵张器行犬双侧下颌骨牵张延长术,7只杂种犬双侧下颌骨第2、3前磨牙之间行截骨术,术后7天开始牵引, 0.5 mm/次,2次/d,共20 d.牵张过程中随机一侧给予40 mW/cm2超声刺激,10 min/次,2次/d,另一侧做遮蔽对照.于牵张完成当日及1、2、4、6、8、12周时对动物进行放射性核素骨扫描观察.结果:牵张完成早期随时间的延长,实验侧牵张间隙区出现核素浓聚,放射强度明显高于对照侧.中后期对照侧核素浓聚度强于实验侧.牵张完成12周,实验侧和对照侧核素浓聚均变弱,基本与正常骨组织浓聚度相近,两侧的差异明显变少.结论:低强度脉冲超声有促进牵张新骨成熟的作用.     

低强度脉冲超声在种植牙同期植骨术后的疗效观察

目的：观察低强度脉冲超声（low intensity pulsed ultrasound,LIPUS）对促进种植牙植骨后骨形成的影响。方法：将40例骨量不足、同期进行植骨和植入人工种植体的病例随机分为LIPUS治疗组和对照组,每组各20例,治疗组于术后第3 d开始应用LIPUS治疗8 w。对照组不做特殊处理。所有患者均于术后当日、2、8、12、24 w拍摄CBCT片,观察骨形成情况,对两组患者的骨形成定量检查结果进行统计学分析。结果：LIPUS治疗组新骨形成时间明显短于对照组,X线片新骨定量检查结果表明LIPUS治疗组8 w时新骨形成优于对照组。结论：临床应用LIPUS治疗能够显著促进种植牙同期植骨后的新骨形成。     

低强度脉冲超声在正畸骨改建中的研究进展

低强度脉冲超声(low-intensity pulsed ultrasound,LIPUS)是强度介于30～100 mW/cm2、频率低于3 MHz的脉冲式超声波,其广泛参与调控成骨细胞、牙周膜细胞及牙骨质细胞的增殖、分化等多项生理功能,最终发挥加快牙移动速度、保护牙根组织的效应.本文就近年来LIPUS对正畸中骨改建调控作用的研究进展进行综述,以进一步加深对LIPUS生物学功能的理解.     

低强度脉冲超声在正畸骨改建中的研究进展

低强度脉冲超声(low-intensity pulsed ultrasound,LIPUS)是强度介于30～100 mW/cm2、频率低于3 MHz的脉冲式超声波,其广泛参与调控成骨细胞、牙周膜细胞及牙骨质细胞的增殖、分化等多项生理功能,最终发挥加快牙移动速度、保护牙根组织的效应.本文就近年来LIPUS对正畸中骨改建调控作用的研究进展进行综述,以进一步加深对LIPUS生物学功能的理解.     

低强度脉冲超声在正畸骨改建中的研究进展

低强度脉冲超声(low-intensity pulsed ultrasound,LIPUS)是强度介于30～100 mW/cm2、频率低于3 MHz的脉冲式超声波,其广泛参与调控成骨细胞、牙周膜细胞及牙骨质细胞的增殖、分化等多项生理功能,最终发挥加快牙移动速度、保护牙根组织的效应.本文就近年来LIPUS对正畸中骨改建调控作用的研究进展进行综述,以进一步加深对LIPUS生物学功能的理解.     

低强度超声在下颌埋伏智牙拔除术中的应用

目的:观察埋伏阻生牙拔除术后应用低强度超声照射对缓解疼痛、肿胀、干槽症和促进骨愈合的效果。方法:在门诊患者中,依据曲面断层X线片选择两侧埋伏阻生程度相近者为研究对象,一侧创口术后照射低强度超声,另一侧进行常规处理。应用SPSS10.0软件对患者手术后疼痛、肿胀、干槽症和创口完全骨愈合的情况进行统计学分析。结果:实验组和对照组比较,实验组疼痛4例,对照组16例(P<0.05);实验组肿胀11例,对照组13例(P>0.05);实验组发生干槽症患者0例,对照组4例(P<0.05);实验组创口完全骨愈合35例,对照组21例(P<0.01)。结论:埋伏阻生牙拔除术后应用低强度超声,可以显著缓解术后疼痛,降低干槽症发生率,并促进创口骨愈合,但是对术后肿胀的治疗效果不明显。     

低强度脉冲超声对牵张成骨新骨形成的研究进展

低强度脉冲超声是一种波动形式,也是一种能量形式,以其机械效应和理化效应为作用基础,在体内传播时,可引起生物体系的功能或结构发生变化,有效促进牵张成骨的愈合,缩短治疗时间。笔者就低强度脉冲超声促进牵张成骨愈合的作用机制进行探讨,并对其动物试验、临床应用研究进行总结。作为促进牵张成骨愈合的一种方法,它具有无不良反应,应用简单等优点。     

低强度脉冲超声在下颌骨骨折愈合过程中的应用

目的:观察低强度脉冲超声(low intensity pulsed ultrasound, LIPUS)促进下颌骨骨折临床愈合的效果.方法:下颌骨骨折病例分为LIPUS治疗组和对照组,每组各20例,所有病例采用颌间固定或微型钛板内固定,于术后3d开始治疗组行LIPUS治疗,1次/d×4周.分别记录骨折临床愈合时间,同时在伤后2周、4周、6周分别摄下颌骨正侧位片,观察骨折线愈合情况,将两组病例的骨折临床愈合时间及X线片骨折线愈合定量检查结果进行统计学分析.结果:LIPUS治疗组骨折临床愈合时间明显短于对照组,X线片骨折线愈合定量检查结果表明LIPUS治疗组4～6周时骨折愈合明显优于对照组.结论:应用LIPUS治疗能够促进下颌骨骨折愈合.     

Effect of low intensity pulsed ultrasound stimulation on sinus augmentation in rabbits

Objectives

The objective of the present study was to evaluate the efficacy of low intensity pulsed ultrasound stimulation (LIPUS) and to determine the optimal frequency for enhancing bone regeneration in sinus augmentation using a rabbit model.

Material and methods

Thirty male rabbits underwent sinus augmentation. Two rectangular nasal bone windows were outlined bilaterally. LIPUS was applied at two different frequencies (1 MHz and 3 MHz) on experimental sites daily for 2, 4 and 8 weeks. Each histological area of the experimental and control sites was divided into upper and lower parts from the parietal region to a depth of 5 mm. Each area of new bone was measured.

Results

At 2, 4 and 8 weeks, the experimental sites in the 1 MHz group exhibited significantly more new bone growth than the control sites in both the upper and lower parts. When the upper and lower parts of each area were measured in combination there was a statistical difference between the test and control sites in the 1 MHz group at 2, 4 and 8 weeks; however, there were no statistical differences between the test and control sites in the 3 MHz group.

Conclusions

The results suggest that clinical application of LIPUS for sinus augmentation may promote new bone formation, and that the effect of LIPUS for sinus augmentation at a frequency of 1 MHz was greater than at 3 MHz until 8 weeks after sinus augmentation.     

The effect of low-intensity pulsed ultrasound on the osseointegration of titanium dental implants

Our aim was to record the effect of low-intensity pulsed ultrasound (LIPUS) on the osseointegration of endosseous dental implants in 10 New Zealand rabbits. One titanium implant with screw was inserted into the metaphyseal region of each femur and tibia in the knee joints of each rabbit, making a total of 40 implants. The area of one lateral knee joint, including implants, was irradiated with LIPUS for 10 min twice a day for 21 days. The other side acted as control, having been given "sham" irradiation. Two rabbits were killed at each of 0, 2, 4, 6, and 8 weeks after irradiation. A micro-computed tomogram (μCT), histological examination, and implant pull-out test were used to judge the reactions of the bone to the titanium implant. Histological and μCT examinations showed that osseointegration of the implants on the LIPUS-treated side happened earlier and more effectively than on the control side. The mechanical test showed that the maximal axial pull-out strength of the implants on the LIPUS-treated side was greater than that on the control side. We conclude that LIPUS has the potential to accelerate the osseointegration of dental implants.     

A preliminary study of the effect of low intensity pulsed ultrasound on new bone formation during mandibular distraction osteogenesis in rabbits

This study assesses the effect of low intensity pulsed ultrasound (LIPUS) on new bone formation during mandibular distraction osteogenesis (DO) in rabbits. 24 rabbits underwent DO on the right side of the mandible. 12 rabbits received a daily 20-min LIPUS (1.5 MHz, 30 mW/cm²) treatment on the first day of the distraction until they were killed at week 0 (immediately after the distraction), week 2 and week 4 after the distraction. Four rabbits were killed at each time point. The other 12 rabbits followed the same protocol without the ultrasound treatment. A plain radiography, a micro-CT scan, a microhardness test and a histological examination were used to evaluate new bone formation in the distraction gap. At week 0 and week 2 after the distraction, the treatment groups showed higher radiopacity and microhardness (p < 0.05), and more bone formation was detected by the histological examination. At week 4 after the distraction, there was no statistical difference between the two groups. In this study, LIPUS accelerated new bone formation during the distraction period and 2 weeks after the distraction, which implies that the effective time for using LIPUS is in the early stage of DO.     

Effect of low intensity laser irradiation on surgically created bony defects in rats

Low intensity lasers have been used by clinicians to improve healing and reduce pain in humans. Lasing also results in new bone formation around hydroxyapatite implants and a significant increase in the total bone area. However, the exact mechanism of cell biostimulation by laser is still unclear. This study biochemically assessed the effects of low intensity laser (Gallium-Arsenide) using 4 and 22.4 mW cm(-2) power density on the bone healing process after surgically creating bony cavities in rat mandibles. Rats (n = 24) were divided into two groups each treated with specific energy, 4 or 22.4 mW cm(-2), for 3 min each day post-surgery. Surgical cavities were created on both sides of the mandible: the left served as an untreated control, the right was treated with laser. All rats were sacrificed after 1, 2 and 4 weeks of treatment. In the newly formed callus, accumulation of radiocalcium and alkaline phosphatase activity was measured to indicate osteogenic activity. One-way anova with repeated measures showed that the low intensity laser using 4 mW cm(-2) power density significantly increased radiocalcium accumulation from 2 weeks post-surgery, whereas 22.4 mW cm(-2) had no effect. No changes were noted in the activity of alkaline phosphatase with the laser treatment. These results suggest that laser therapy of low power density is effective on the bone healing process in artificially created osseous cavities by affecting calcium transport during new bone formation.     

低强度脉冲超声波联合引导骨组织再生促进牙周骨缺损修复的实验研究

目的探讨低强度脉冲超声波（LIPUS）联合引导骨组织再生（GBR）对Beagle犬尖牙牙周骨缺损的修复效应。方法将8只Beagle犬中每只犬的4颗尖牙随机分配到4组：实验1组（LIPUS处理+GBR+自体骨移植组）,实验2组（LIPUS处理+自体骨移植组）,实验3组（GBR+自体骨移植组）,空白对照组。在犬尖牙颊侧区根中1/3处制备牙周骨缺损模型,根据分组,自体骨移植后,实验1组和2组采用LIPUS处理20 min·d-1,超声强度为30 mW·cm-2,实验1、3组植入Bio-Gide胶原膜。在LIPUS处理6、8周后处死Beagle犬,对各组尖牙牙周骨缺损区进行Micro-CT检测和分析。结果临床观察各组牙周骨缺损面积均不同程度缩小。Micro-CT检测分析表明,各组6周与8周时的骨小梁数目、骨小梁厚度和骨小梁体积均无统计学差异（P＞0.05）,而各组之间的骨组织测量指标均有统计学差异（P＜0.05）,实验1组新生骨量最多。结论LIPUS具有促进牙周骨缺损修复的潜能,LIPUS与GBR结合可能更有利于牙周骨缺损的修复与再生。