矫形力对羟基磷灰石涂层的钛支抗种植体骨界面影响的研究

目的：了解在矫形力作用下的HA涂层钛种植体骨界面情况。方法：在狗下颌骨延期植入8枚种植体，施以2.9N和5.9N的矫形力，通过三色荧光标记和组织学切片的形态学研究支抗种植体骨界面情况。结果：HA涂层钛支抗种植体在矫形力作用3个月后仍然稳定，种植体界面为骨整合,2.9N与5.9N矫形力对种植体周围骨改建的影响无差别。结论：HA涂层种植体在短期内受矫形作用下稳定，可用做正畸矫开支抗。     

羟基磷灰石涂层种植体—骨界面的生物力学研究

本项研究选用氧化铝作为种植体基体．在850℃和1050℃下分别在其表面烧结羟基磷灰石(简称HA)．制成HA1和HA2涂层种植体．以纯钛作对照。狗股骨穿皮质种植1、3、6个月后取材，行顶出试验．并对测试后的破坏断面行扫描电镜观察。结果发现：两种HA涂层种植体具有较好的生物力学性能．能在种植早期加速新骨形成、钙化，达到较高的界面结合强度；涂层种植体在顶出试验后．断裂发生在涂层材料内，而纯钛则发生在种植体—骨组织界面；涂层种植体的界面力学性能和烧结温度有关．HA2涂层种植体在各种植程期的界面结合强度均高于HA1涂层种植体。     

生物陶瓷涂层复合种植体骨界面的剪切强度

本文以恒河猴为实验对象,以未涂层纯钛种植体为对照,用力学测试方法研究两种生物活性玻璃陶瓷涂层种植体植入股骨后,种植体——骨界面的剪切强度。结果表明:两种生物活性玻璃陶瓷涂层种植体,与未涂层种植体相比,在种植早期较快与骨形成牢固的结合。其中,又以M—涂层种植体更明显,它的平均界面剪切强度,在种植后3个月是未涂层者的2至3倍。     

支抗种植体直径对骨界面应力分布的影响

目的 :研究不同直径支抗种植体对骨界面应力分布的影响 ,以供临床筛选合适的种植体。方法 :用三维有限元方法给种植体施加 1.47N(150 g)近远中方向的载荷 ,分别对直径为 3 .0、3 .75、5.0mm的支抗种植体 骨界面进行应力分析。结果 :3种直径种植体颈部的Von Mises应力值分别为 0 .80 7、0 .53 3、1.0 80 ;位移值分别为 0 .2 3 2、0 .163、0 .111μm。结论 :在选择正畸支抗种植体时 ,直径为 3 .75mm的种植体较适宜作正畸支抗体     

支抗种植体长度对骨界面应力分布的影响

目的：研究不同长度支抗种植体对骨界面应力分布的影响，以供临床筛选合适的种植体。方法：用三维有限元方法给种植体施加150g近远中方向的载荷，分别对长度为7mm、10mm、15mm的支抗种植体-骨界面进行应力分析。结果：三种长度种植体颈部的Von-Mises应力值分别为0．5450MPa、0．5330MPa、0．5320MPa；位移值分别为0．1690μm、0．1630μm、0．1610μm。结论：在种植体承受侧向力载荷时，增加种植体长度可提高其承载能力，临床上在选择正畸支抗种植体时，应尽量选择长种植体作正畸支抗体。     

正畸力作用方向对支抗种植体-骨界面应力分布的影响

目的：研究正畸力不同作用方向对种植体-骨界面应力分布的影响，以指导临床选择合适方向的正畸载荷。方法：用三维有限元方法给种植体施加150g近远中向、颊舌向及轴向载荷。对支抗种植体一骨界面进行应力分析。结果：三种方向载荷下种植体颈部，(1）Von—Mises应力值分别为：(a)近远中向——0．5330MPa；(b)颊舌向——颊侧为0．51520MPa，舌侧为0．6470MPa；(c)龈he向——颊侧为0．0702MPa，舌侧为0．0791MPa，近远中向为0．0517MPa。(2)位移值分别为：(a)近远中向——0．1630μm；(b)颊舌向——颊侧为0．2070μm，舌侧为0．1950μm；(c)龈he向——颊侧为0．0496μm，舌侧为0．0467μm，近远中向为0．0484μm。结论：在植入支抗种植体时。应根据正畸载荷力的形式．适当调整种植体的部位，尽量不要过于偏颊、舌侧，以免造成应力的过分集中，导致骨组织损伤。     

含镁羟基磷灰石涂层对卵巢摘除大鼠种植体骨整合的影响

目的探讨羟基磷灰石涂层(hydroxyapatite,HA)中加入镁元素对植入卵巢摘除(ovariectomized,OVX)大鼠体内种植体的稳固性的影响。方法采用溶胶-凝胶法制备种植体表面涂层,对照组为传统的羟基磷灰石涂层,实验组为用镁元素替代羟基磷灰石中10%钙元素的涂层(magnesium-containing hydroxyapatite,MgHA)。另取18只OVX大鼠,随机分为2组,一组在双侧股骨远心端各植入1枚HA涂层种植体,另一组则植入MgHA涂层种植体。12周后,连同周围骨组织取出种植体进行组织形态计量分析、Micro-CT评价、生物力学测试。结果 MgHA组骨-种植体接触率、骨面积比率分别为(52.57±4.73)%、(36.76±3.31)%,HA组为(34.06±5.20)%、(27.26±2.92)%;MgHA组的最大推出强度、界面剪切强度为(63.98±4.08)N,(2.63±0.25)N/mm2,HA组为(41.44±7.07)N,(2.22±0.33)N/mm2,P<0.01。此外,MgHA组骨体积分数(24.5±6.1)%、骨小梁厚度(80.6±11.9)μm、骨小梁数量(5.8±0.5)mm-1、骨小梁分离度(194.7±38.2)μm、连接密度(51.9±5.6)mm-3、骨整合率(58.6±6.2)%;而HA组为(16.6±4.3)%、(68.4±10.3)μm、(5.2±0.6)mm-1、(220.8±30.6)μm、(44.1±4.5)mm-3、(45.1±3.8)%,除骨小梁分离度无统计学差异外,其余P<0.05。结论镁元素能改善骨质疏松骨中种植体的生物性能。     

氮化硅复合种植体-骨界面的剪切强度

目的：测试并分析新型种植体及钛种植体与骨的剪切强度。方法：以Ｂｅａｇｌｅ犬为实验对象,羟基磷灰石（ＨＡ）涂层钛种植体及钛合金种植体为对照,用力学测试方法研究新型种植体－氮化硅复合羟基磷灰石涂层种植体和单一氮化硅种植体植入股骨后,不同时期种植体－骨界面的剪切强度。结果：两种有涂层的种植体植入后１个月,其界面剪切强度高于非涂层者,但３个月后实验组的两种种植体界面剪切强度明显高于对照组,与骨形成更牢固的     

微螺钉正畸支抗种植体

正确的支抗设计和控制是正畸治疗成功的重要因素,正畸种植体支抗技术是口腔正畸学与修复学、材料学、口腔颌面外科学等学科之间交流融合的产物,是近年来正畸临床上具有突破性的进展,众多支抗种植体的出现丰富了正畸支抗设计的内容。 微螺钉支抗种植体是目前临床较常用的正畸支抗种植体,根据植入方式可分为助攻型和自攻型2类。助攻型微螺钉支抗种植体在植入前需要先用圆钻钻开骨皮质,然后用骨钻形成通道以引导植入(pilot drilling),最后将螺钉自身顺通道拧入(self tapping)。自攻型微螺钉支抗种植体,又称为自钻型(self drilling)微螺钉支抗种植体,可以直接攻入皮质骨,不需要骨钻引导,甚至不需要钻开骨皮质。另外,根据正畸治疗时微螺钉的头部是否暴露于口腔中,还可将手术方法分为开放式(openmethod)和闭合式(cbsed method),前者微螺钉的头部暴露于口腔中,后者微螺钉的头部埋植于软组织中,主要用于种植部位较深时(如颧弓)。需要指出的是;正畸用支抗螺钉种植体的直径多在1.2-2.7 mm之间,骨内长度在7-15 mm之间,比较常用的直径在1.5-2.0 mm、骨内长度在7-11 mm之间。一般直径较小者(2.0mm以下)称为microscrew(微螺钉),直径在2 mm以上者称为miniscrew(小螺钉)。 目前较有代表性的微螺钉正畸支抗种植体系统主要有:(1)MIA系统(Micro Implant Anchorage):由韩国庆北大学开发,种植体为直径1.2 mm、长6 mm的纯钛螺钉,助攻型,软组织愈合2周后可直接负载,能够有效承受200-300 g正畸力。2004年最新的产品螺钉直径加大为1.3-1.8 mm不等,长度在5-12 mm之间。直径在1.5 mm以上的螺钉植入时采用自攻方式。(2)OSAS系统(Osseodyne Skeletal Anchorage System):由韩国汉城国立大学和EPOCH公司联合开发生产,螺钉直径1.6mm,长度分9mm(上颌)和7mm(下颌)两种,自攻型,在附着龈处植入时无需切开龈黏膜,在     

钛铸件与三种钛瓷粉结合强度的对比研究

目的 :观察钛铸件与VitaTitankeramik、TiBond和NoritakeTi2 2三种钛专用瓷粉的结合强度 ,分析钛/瓷结合强度的影响因素。方法 :根据ISO 9693标准 ,运用三点弯曲方法对钛 /瓷和Ni -Cr/瓷的结合强度进行测试 ,并对钛 /瓷结合界面进行SEM /EDS观察与分析。结果 :钛 /TiBond结合强度 ( 3 0 .96± 3 .0 6)MPa、钛 /VitaTi tankeramik结合强度 ( 3 5 .18± 3 .0 6)MPa ,钛 /NoritakeTi2 2结合强度 ( 3 8.5 4± 3 .0 6)MPa ,均大于ISO所要求的基本值 2 5MPa ,但仍明显小于Ni-Cr/瓷的结合强度 ( 4 8.3 5± 3 .0 6)MPa(P <0 .0 1)。钛 /VitaTitankeramik界面存在大量的孔隙 ,瓷对钛的浸润性较差。钛 /NoritakeTi2 2界面瓷与钛基体相互交错 ,结合紧密。结论 :钛 /瓷结合强度可满足临床需要 ,但仍需进一步改善     

Torsional stability of HA-coated and grit-blasted titanium dental implants.

Hydroxylapatite (HA)-coated and grit-blasted (non-HA-coated) titanium dental implants were inserted into healed extraction sites of canine mandibles. After six weeks, the animals were killed and the implants mechanically tested in torsion to failure. Interface attachment strength, implant/tissue compatibility, integrity of the HA coating, and the location of interface failure were evaluated. Mechanical testing demonstrated an interface torsional strength of 3.98 +/- 0.93 MPa for the HA-coated implants and 2.25 +/- 0.65 MPa for the grit-blasted implants. This represents a 76.9% improvement in the maximum torsional interface strength, and is statistically-significant (p = 0.0004). On qualitative histologic analysis, interface failure was seen to occur primarily at the HA/implant interface, although failure through the HA coating and regions of bone/HA interface failure were observed. The HA-coated implants had bone in direct apposition to their surface with no fibrous tissue interposition. The grit-blasted implants also had regions of direct bone-implant apposition, but these areas were limited to a smaller proportion of the total interface area. There was no evidence of breakdown or change in thickness of the HA coating.     

Bone response to plasma-sprayed hydroxyapatite and radiofrequency-sputtered calcium phosphate implants in vivo

PURPOSE: The objective of this study was to evaluate the effect of radiofrequency- (RF) sputtered calcium phosphate (CaP) coating of titanium implants on bond strength at the bone-implant interface and percent bone contact length. MATERIALS AND METHODS: Cylindric sputtered CaP-coated and plasma-sprayed hydroxyapatite- (HA) coated implants (4.0 mm diameter and 8 mm length) were implanted in dog mandibles. Half the sputtered CaP-coated implants were heat-treated. RESULTS: Twelve weeks after implant placement, no statistical differences in the mean ultimate interfacial strengths were observed between as-sputtered CaP-coated, sputtered CaP-coated heat-treated, and control plasma-sprayed HA-coated implants. Histomorphometric evaluation indicated that the percent bone contact lengths for the plasma-sprayed HA-coated implants and the as-sputtered CaP-coated implants were similar and significantly greater than that for the sputtered CaP-coated heat-treated implants. Differences in the ultimate interfacial strength and percent bone contact length between different implant sites in the mandible were not observed. DISCUSSION: The results of this study, considered together with the results of previous studies, suggest that once early osseointegration is achieved, biodegradation of the thin CaP coatings is not detrimental to bone-coating-implant fixation, and does not compromise bone responses to the coated implant surfaces. CONCLUSION: The interfacial strength and histomorphometric data suggest that the CaP coatings applied using the sputtering process produce bone responses similar to those of HA coatings applied using plasma spraying.     

Effects of anodized implants coated with Escherichia coli-derived rhBMP-2 in beagle dogs

This study evaluated the effects of Escherichia coli-derived rhBMP-2 (ErhBMP-2) coated onto anodized implants to stimulate bone formation, osseointegration and vertical bone growth in a vertical bone defect model. Six young adult beagle dogs were used. After a 2-month bone healing period, anodized titanium implants (8 mm in length) were placed 5.5 mm into the mandibular alveolar ridge. Eighteen implants coated with ErhBMP-2 (BMP group) and another 18 uncoated implants (control group) were installed using a randomized split-mouth design. The implant stability quotient (ISQ) values were measured. Specimens were fabricated for histometric analysis to evaluate osseointegration and bone formation. The ISQ values at 8 weeks after implant placement were significantly higher in the BMP group than in the control group (p < 0.05). Histological observations showed that the changes in bucco-lingual alveolar bone levels were higher in the BMP group than in the control group (p < 0.05). The ErhBMP-2 coated anodized implants can stimulate bone formation and increase implant stability significantly on completely healed alveolar ridges in dogs. Further studies evaluating the effects of ErhBMP-2 on osseointegration in the bone–implant interface are warranted.     

Comparative study of hydroxyapatite and titanium dental implants in dogs

This study compares the clinical performances and histologic response in dogs to a cylindrical implant with a surface consisting of dense hydroxyapatite (HA) and a threaded titanium implant in functionally loaded and unloaded conditions. Implantation was performed in five dogs, which were killed at 2 or 4 months postfunctional condition (4 or 6 months after implantation). Clinical evaluation showed that neither implant demonstrated significant movement, and assessment of gingival inflammation and sulcus depth showed no significant differences between them. After axial sectioning, the titanium implants were easily removed from the bone, whereas the HA-coated implants were adherent to the bone. Histologically, both implants showed osteogenic ingrowth to the surface in functional and nonfunctional conditions. High-magnification scanning electron micrographs of plastic sections showed that a portion of the interface between the HA-coated implant and the bone showed no gap, whereas gaps were observed at all interfaces with the titanium implant. Histomorphometric analysis by light microscopy indicated that there was no significant difference in the percent bone contact length. Clinically, the two implants behaved similarly.     

羟基磷灰石涂层钛种植支抗的稳定性

将羟基磷灰石涂层钛种植体处期植入狗颌骨，施以１５０ｇ的正畸力，通过口内及Ｘ线归咎测量，动态研究种植支抗在３个月内的稳定性。结果显示：判断种植支抗的移动应综合采用口内及通过Ｘ线归咎测量两种方法：ＨＡ涂层钛种植支抗的骨内段无移位，而基桩在受力后第２和第３个月倾斜移动。     

钛网成形自体颗粒骨修复下颌骨缺损并同期种植的实验研究

目的 观察犬钛网成形自体颗粒骨移植修复下颌骨节段性缺损并同期植入钛种植体后的骨愈合和骨结合情况.方法 5只Beagle犬,一侧下颌骨制备长40 mm的节段性缺损;钛网成形修复下颌骨缺损.将切除后的下颌骨和自体髂骨剪成直径约2mm颗粒,骨皮质、骨松质体积比3∶1混合,紧密充填在钛网内,将2枚纯钛种植体埋置于颗粒骨内,术后6个月处死动物.用下颌骨X线片、组织学切片、扫描电镜以及能谱分析观察钛网内颗粒骨愈合以及种植体骨结合的情况.结果 钛网成形自体颗粒骨移植重建后的下颌骨外形满意,功能正常、颗粒骨成骨良好、结构优良,未见明显骨吸收.同期植入的种植体能够与周围骨组织形成良好的骨结合,并有促进邻近骨组织结构优化的趋势.结论 钛网成形自体颗粒骨移植是一种修复下颌骨节段性缺损的好方法,当修复后下颌骨形态良好、骨质优良、骨量充足时可以同期植入种植体.     

羟基磷灰石涂层种植体骨愈合的实验研究

目的：通过动物实验，研究涂覆烧结工艺技术研制的新型羟基磷灰石（HA）涂层种植体的骨愈合情况。方法：将12颗钛种植体（6颗有HA涂层，6颗无涂层）植入6只成年杂种犬下颌骨内，分别饲养1、3、6个月，使种植体在无负荷的条件下愈合。标本进行大体观察、光镜组织学观察以及计算机定量组织形态学评价。结果：两种种植体都能产生骨结合。有涂层的种植体新骨的产生和成熟都比无涂层的钛种植体更为迅速。术后1、3、6个月有涂层种植体的骨结合率分别为71．68％、86．81％、90．19％；无涂层种植体的骨结合率为53．26％、66．16％、68．72％，其间有显著性差异（P＜0．01）。结论：涂覆烧结工艺HA涂层骨内种植体能取得良好的骨结合，涂覆烧结工艺HA涂层能够很好地促进种植体的骨结合。     

Marginal bone loss pattern around hydroxyapatite-coated versus commercially pure titanium implants after up to 12 years of follow-up

PURPOSE: The purpose of this study was to compare the marginal bone loss (MBL), complications, and 12-year survival rates of commercially pure titanium (cpTi) and hydroxyapatite (HA)-coated implants placed in the maxilla. MATERIALS AND METHODS: The study group consisted of 120 patients (77 women, 43 men) treated from 1988 to 1997. A total of 388 implants (156 cpTi and 232 HA-coated) were placed in the maxilla. There were 126 immediate (32.5%) and 262 (67.5%) nonimmediate implants. Patients were evaluated annually. Mean follow-up was 60 +/- 32.3 months. MBL was measured on radiographs using the implant threads as the dimensional reference. MBL, complications, and 12-year survival and success rates were correlated with implant coating, time of implantation, implant dimensions, and position in arch. RESULTS: Total mean MBL was 1.07 +/- 2.16 mm. MBL was significantly lower with cpTi implants (0.55 +/- 1.04 mm) compared to HA-coated implants (1.51 +/- 2.71 mm) (P < .001). No statistical difference in regard to MBL was found between immediate and nonimmediate implants (0.86 +/- 1.8 mm vs 1.16 +/- 2.3 mm). The total 12-year survival rate was 91.4%. HA-coated implants had a significantly higher 12-year survival rate than cpTi implants (93.2% vs 89%; P < .03). Nonimmediate implants had a significantly higher failure rate (8.2%) than the immediate implants (1.3%) (P < .009). No correlation was found between type of implant coating and late implant failure. DISCUSSION: Immediate implants can serve as a predictable option, providing higher survival and success rates. HA-coated implants tended to fail less during the surgical phase, but had higher mean MBL compared to cpTi implants. CONCLUSIONS: HA-coated implants had greater MBL than cpTi implants but a higher 12-year survival rate. Immediate implants had a lower failure rate than the nonimmediate implants in this study population.     

3D打印多孔钽种植体对骨整合影响的实验研究

目的 研究多孔钽及多孔钛种植体对骨整合的影响。方法 通过计算机辅助设计方法建模,采用3D打印技术制备两种微孔参数相同的多孔材料种植体：多孔钽及多孔钛。在24只新西兰大白兔双侧股骨外踝处建立骨缺损模型,每只动物左右侧缺损随机分组,分别用多孔钽（实验组）和多孔钛（对照组）种植体进行修复。种植体植入后2、4、8周取材,进行大体观察和亚甲基蓝-酸性品红染色,观测种植体和骨界面的骨整合情况,采用推出实验测试种植体-骨界面结合强度。 结果 术后2、4、8周,两组材料界面的新生骨组织逐渐增加,出现新生骨小梁并向材料孔隙内生长;两组的成骨情况及种植体-骨组织界面结合强度的差异无统计学意义（P>0.05）。结论 3D打印的多孔钽能与骨组织形成早期的生物结合,具有与多孔钛相当的骨整合能力。     

钛种植体-羟基磷灰石复合型植入体修复下颌骨缺损的动物实验

本研究采用钛种植体-羟基磷友石复合型植入体植入20只狗下颌骨牙缺失区．并对植入体与宿主骨结合的过程进行了X线、组织形态学观察和复合型植入体抗折强度测试。结果表明：术后12周．复合型植入体的抗折强度比植入体内前高；复合型植入体植入后用微型钛夹板固定组与宿主骨呈骨性结合；用骨膜复位缝合固定组与宿主骨呈纤维骨性结舍。钛种植体与羟基磷灰结合牢固．负荷条件下无松脱落。复合型植入体不干扰骨愈合过程。作者认为该种复合型植入体可用于颌骨缺损后的牙颌整复．但植入体植入后早期的稳定固定则十分重要。