对缩短椅旁工作时间正畸种植支抗方法的分析

目的:对微螺钉支抗种植进行分析,找出失败的原因,为各位同道提共成功的种植经验.方法:对64例各类错牙合畸形采用方丝弓矫治技术配合自攻型微螺钉支抗种植体进行了矫治,按微螺钉支抗的标准规程操作,共计种植微螺钉128颗,分剔对即刻种植后、种植4周启及负载后4周的稳定性进行统计分析.微螺钉支抗种植体的种植成功与失败情况通过其脱落率及折断率来评价.结果:64例128颗微螺钉支抗种植体,共有6例8颗脱落,成功率为93.75%,脱落率为6.25%,其中种植后即刻脱落2例4颗,4周后脱落1例2颗,负载4周后脱落2例2颗,无种植体折断情况发生.结论微种植支抗体的种植成功率与种植手术的术式、技巧及手术设备、环境有关,同时,患者的个体因素年龄、性别、骨密度及口腔卫生情况也是微种植支抗种植成功及能否成功行使功能的关键.     

微螺钉种植体支抗稳定性的临床观察

目的分析微螺钉种植体作为支抗的稳定性。方法选择35例错颌畸形患者,共植入种植钉84枚,观察其在行支抗功能过程中的松动脱落情况。结果 84枚微螺钉种植体中,11枚出现松动脱落,成功率86.9%,脱落率13.1%。结论微螺钉种植体作为支抗性能稳定,疗效肯定,操作简单,是正畸治疗过程中理想的支抗选择。     

微螺钉种植支抗稳定性的临床研究

目的：研究微螺钉加载正畸负荷后的稳定性。方法：本研究包括了15例成年患者，以植入上颌颧突的微螺钉作为前牙内收的颌内支抗。微螺钉植入2周后施力。加力前及加力后9个月分别拍摄X线头颅定位片，将头影测量片进行重叠，测量微螺钉的移位变化。结果：15例中6例患者的微螺钉伸出并移位（-0．5～1．5mm）。微螺钉头部平均向前移位0．4mm，有统计学意义（P〈0．05）。结论：微螺钉是一种稳定的支抗装置，但是在承载正畸负荷的过程中，并不保持绝对的稳定，部分微螺钉在正畸力作用下有移位。为了防止因微螺钉移位伤及临近的重要组织结构，建议微螺钉应植入在没有主要神经、血管通过的非齿槽骨区，或植入在齿槽间隔区，但微螺钉与牙根之间应留出2mm的安全距离。     

微不锈钢种植体支抗的稳定性研究

目的：分析不同施力时间对微不锈钢种植支抗稳定性的影响。方法：选择20例错牙合畸形患者（男10例,女10例）,年龄16～18岁,分别将种植钉被植入每位患者上颌两侧第一前磨牙和第一磨牙区作为种植钉支抗内收前牙,共植入40颗不锈钢种植钉。男女患者按加载时间不同被随机平分为两组,实验组1：种植钉植入后便采用镍钛拉簧即刻加力,实验组2：4周后在进行加力,分别通过头颅侧位片测量种植钉加载前后半年的位移变化。然后对两个实验组进行统计学分析。结果：实验组1：种植钉在矢状向上平均移动了1.31mm,垂直向上平均移动了1.53mm。实验组2：种植钉在矢状向和垂直向的平均位移是0.83mm和1.03mm。结论：不锈钢种植钉能够为内收前牙提供稳定和可靠的支抗,植入4周后再施力更有助于种植钉的稳定。     

自攻型微螺钉种植体内收上前牙的临床研究

目的：评价自攻型微螺钉种植体作为正畸支抗内收上前牙的有效性。方法：从临床病例中选择30例矫治设计拔除4颗第一双尖牙、上颌强支抗的双颌前突患者,均采用自攻型微螺钉种植体作为支抗手段,植入部位选择在上颌第二双尖牙和第一磨牙牙根间的颊侧牙槽骨,植入4周后施加350g以内矫治力,观察微螺钉种植体的稳定性,并对30例患者治疗前后X线头颅侧位片进行测量,评价治疗效果。结果：微螺钉种植体5个月内的成功率为93.3%,稳定性高。30例双颌前突患者上前牙内收效果明显,获得了磨牙强支抗的效果。结论：微螺钉种植体能作为稳定的正畸支抗,能有效地内收上前牙,起到了加强磨牙支抗的效果。     

微小种植体支抗的脱落情况分析

目的:分析不同植入部位、不同植入时间微小种植体支抗的脱落的情况,寻找导致微小种植体脱落的最可能原因,以利于临床工作需要。方法:记录176例患者植入的349枚微小种植体植入部位、植入时间及其中脱落的29枚微小种植体的植入部位、植入时间并进行统计分析。结果:植入总成功率为91.6%。植入在腭侧的19枚,及植入在上下颌两侧第二前磨牙近中区域的28枚微小种植体均未见脱落;微小种植体上下颌脱落率有显著性差异;不同年份微小种植体脱落率有显著性差异。结论:植入手术操作是影响微小种植体植入成功率的最主要因素。     

音乐疗法在微螺钉种植体支抗植入中的应用

目的:探讨音乐疗法在微螺钉种植体支抗植入中的应用效果。方法:纳入2019年-2020年于西安交通大学口腔医院正畸科行微螺钉种植体支抗植入的患者102例,采用随机数表法分为对照组(n=51)及音乐疗法组(n=51),以问卷调查及访谈形式评估音乐疗法对缓解患者焦虑情绪、提升患者满意度的效果。结果:两组术前、术中、术后恐惧程度评分及术后并发症恐惧程度评分比较,差异无统计学意义(P0.05);音乐疗法组手术总体满意度、护理质量满意度、护理态度满意度及再次进行微螺钉种植体支抗植入手术评分均高于对照组,差异有统计学意义(P0.05)。问卷结果及访谈主题分析法均提示音乐疗法可以有效缓解患者术前、术中及术后等不同阶段的焦虑,提升治疗及护理满意度。结论:音乐疗法是一种有效的微螺钉种植体支抗植入中的护理配合方法,值得进一步推广应用。     

微种植体植入角度对微种植体稳定性的影响

目的:通过有限元方法,分析微种植体植入角度对微种植体稳定性的影响,为微种植体支抗的临床应用提供可靠的理论依据.方法:建立不同植入角度的微种植体-上颌全牙弓有限元模型,对各模型施加2.5N内收前牙的作用力,对微种植体所受等效应力进行比较.结果:微种植体与牙槽骨表面的夹角增加,微种植体所受等效应力明显减小.结论:微种植体植入角度的增加,有利于微种植体的稳定.     

保留末端基牙在无牙颌精确种植中的应用

目的:探讨保留末端基牙制作牙-黏膜支持式导板在无牙颌精确种植中的应用,并与无牙颌黏膜支持式导板的精准性进行比较。方法:选择临床上无牙颌种植患者18例共98颗种植体,分成两组。牙-黏膜组利用末端基牙制作牙-黏膜支持式数字化种植导板进行无牙颌种植体植入;黏膜组没有可利用的末端基牙,常规制作数字化黏膜支持式导板植入种植体。记录种植留存率及患者满意度。比较两组种植体植入前后位置差异测量值。所有患者术后随访6～20个月。结果:种植体的总存留率为98.97%,患者满意度较高。牙-黏膜组种植体植入颈部距离、尖端距离、植入深度、植入角度偏差均显著小于黏膜组(P0.05)。结论:选择可以保留的末端基牙制作牙-黏膜支持式导板可以提高无牙颌种植的精准性及临床操作便利性,易于实现即刻修复,术者及患者的满意度比较高。这种治疗方案值得在全口种植即刻修复中推广。     

计算机辅助设计腰椎融合器的生物力学评价

目的探讨新型计算机辅助设计腰椎椎间融合器和2种常用的椎间融合器在PLIF附加椎弓根螺钉术后的生物力学稳定性。方法选用经过检查无损伤(肿瘤、外伤、手术)的10具成人新鲜冰冻尸体脊柱标本(L4~S1)进行实验分组:①完整标本组;②行腰椎后路L4,5全椎板切除减压合并椎间隙单纯植骨组;③行腰椎后路L4,5全椎板切除减压、椎间隙单纯植骨合并L4,5椎弓根螺钉组;④行腰椎后路L4,5全椎板切除减压、椎间隙植骨CAPSTONE融合器植入合并L4,5椎弓根螺钉组;⑤行腰椎后路L4,5全椎板切除减压、椎间隙植骨OIC融合器植入合并L4,5椎弓根螺钉组;⑥行腰椎后路L4,5全椎板切除减压、椎间隙植骨CAD-CAGE融合器植入合并L4,5椎弓根螺钉组。各组随机顺序进行7项非损伤性加载,运用数字相关法对不同处理组术后腰椎即刻生物力学指标进行测定,并运用统计学方法分析。结果腰椎后路L4,5全椎板切除术后,与完整标本组和其他固定组相比,在屈曲、左右侧弯、左右旋转6个方向的动态加载下角位移和运动范围显著增大(P<0.01);行PLIF附加椎弓根螺钉固定术后各组,与完整标本和不附加椎弓根螺钉固定组相比,6个方向的动态加载下角位移和运动范围显著减小(P<0.01);使用椎弓根螺钉各个固定组之间比较,单纯椎间隙植骨组仅在屈曲方向的动态加载下角位移和运动范围显著增大(P<0.01),其他各个方向的动态加载下角位移和运动范围差异无统计学意义(P>0.05)。使用椎间融合器的3组之间比较,6个方向的动态加载下角位移和运动范围差异无统计学意义(P>0.05)。结论①腰椎全椎板切除后,腰椎稳定性显著降低。②附加椎弓根螺钉固定可以得到比完整状态更好的腰椎稳定性。③PLIF术式中,采用椎间融合器比不采用融合器,能够使腰椎得到更可靠的稳定性。④融合器外形设计的区别对稳定性影响甚微。     

Peri-implant bone reactions at delayed and immediately loaded implants: an experimental study.

OBJECTIVE: The aim of this study was to compare the peri-implant bone reactions of implants subjected to immediate loading with those subjected to delayed loading. STUDY DESIGN: In 6 mongrel dogs, bilateral edentulated flat alveolar ridges were created in the mandible. After 3 months of healing, 1 implant was placed in each side. On one side of the mandible, the implant was loaded immediately with a force of 20 N that was applied at a 120 degrees angle from the tooth's longitudinal axis at the labial surface of the crown for 1800 cycles per day for 10 weeks. On the opposite side, after a delay of 3 months to allow osseointegration to take place, the implant was loaded with the same force used for the immediately loaded implant. Ten weeks after loading, microscopic computerized tomography at the implantation site was performed. Osseointegration was calculated as the percentage of implant surface in contact with bone. Bone height was measured in the peri-implant bone. RESULTS: The mean osseointegration was greater (65.5%) for the delayed-loading implants than for the immediately loaded implants (60.9%; P < .05). The mean peri-implant bone height was greater (10.6 mm) for the delayed-loading implants than for the immediately loaded implants (9.6 mm; P < .05). CONCLUSION: The results indicate that when implants are immediately loaded, the immediate loading may decrease both osseointegration of dental implants and bone height.     

Preclinical animal study and clinical trail of modified extraoral craniofacial implants.

We report on our experience using a new endosseous implant designed to provide sufficient retention to various types of facial prostheses. In a preclinical animal experiment implants (N=12, 4 x 3.5 mm) were placed in the frontal calvarial region of nine adult pigs. The animals were sacrificed at 2, 4 and 8 weeks to evaluate the implant incorporation microradiographically. The clinical outcome and patient satisfaction of implant-retained prostheses were evaluated in a group of 10 patients with facial defects by using clinical assessment and standardized questionnaires for patients and relatives. In the prospective clinical study 33 identical modified implants for extraoral anchorage were placed for the fixation of various prostheses in the midfacial (eye, nose) and ear regions in the course of a clinical trial and observed over a follow-up period of 34 months. The bone-implant contact in the animal experiment reached 31% (+/-2) at 2 weeks, 39% (+/-1) after 4 weeks and 51% (+/-5) at 8 weeks. In the clinical trial, no implants were lost and all implants remained osseointegrated as confirmed clinically and radiographically, providing a stable prosthetic restoration. The analysis of the questionnaire indicates an improvement of the quality of life of patients with respect to aesthetic and psychological well-being. The results demonstrate that extraoral implants not only achieve sufficient osseointegration but also show good clinical handling and easy fixation possibilities for prosthetic anchorage.     

半导体激光治疗羟基磷灰石义眼座暴露

目的　探讨低功率半导体激光治疗羟基磷灰石义眼座暴露的疗效。方法　采用JAM Ⅱ型多功能半导体激光治疗仪对 2 2例不同程度的义眼座暴露患者进行激光照射治疗 ,并将结果与既往采用药物及手术治疗的 2 0例义眼座暴露患者对照比较。结果　激光组 2 2例全部愈合(10 0 % ) ;药物及手术组中轻、中、重度的愈合率分别为 83 3%、6 3 6 %和 0。经采用卡方检验之四格表精确检验法处理 ,两组间轻度患者的愈合率差异无显著性意义 (P =0 5 4 5 ) ,而两组间中度和重度患者的愈合率差异有显著性意义 (P =0 0 19,0 0 18)。结论　低功率半导体激光治疗羟基磷灰石义眼座暴露的疗效优于药物及手术方法。也可用于预防义眼座暴露。     

牙齿缺失患者常规种植和即刻种植修复后疗效比较

目的:探讨牙齿缺失患者行常规种植和即刻种植修复后的临床效果。方法:选择笔者医院2017年3月-2018年9月收治的118例牙齿缺失患者,根据治疗方法和种植情况分为常规种植组和即刻种植组。常规种植组:62例,给予常规种植进行治疗;即刻种植组:56例,给予即刻种植进行治疗。比较两组患者的临床疗效,观察两组修复后牙槽骨及种植体周围情况。结果:两组治疗后,常规种植组总有效率为100%,即刻种植组总有效率为100%,两组差异不具有统计学意义(P>0.05);常规种植组PES得分(12.3±3.32)分,即刻种植组为(11.8±3.19)分,两组比较差异不具有统计学意义(P>0.05);牙槽骨吸收情况:常规种植组总体吸收程度1.14±0.58,即刻种植组为0.94±0.42,两组比较差异具有统计学意义(P<0.05);常规种植组的临床总满意率88.71%,明显低于即刻种植组的98.21%,两组比较差异显著,具有统计学意义(χ^2=2.05,P=0.04)。结论:常规种植和即刻种植对牙齿缺失进行修复的临床疗效相似,安全性均较高,但相对而言即刻种植可降低牙槽骨吸收,提高患者满意度,值得临床推广应用。     

A preliminary randomized clinical trial comparing diode laser and scalpel periosteal incision during implant surgery: impact on postoperative morbidity and implant survival

The aim of this preliminary randomized clinical trial was to compare: (1) post-operative morbidity after application of laser or scalpel incision for flap advancement during implant surgery and bone grafting and (2) implant survival rate following flap advancement with laser or scalpel incision after 6 months of loading. Eighteen patients who were scheduled for dental implant placement and simultaneous bone grafting were randomly assigned to test or control groups. Diode laser (810 nm, 2 W, pulse interval 200 μs; pulse length 100 μs, 400-μm initiated fiber tip), or scalpel (control) was used to sever the periosteum to create a tension-free flap. Visual analogue scale (VAS) pain score, rate of nonsteroid anti-inflammatory drug (NSAID) consumption, intensity of swelling, and ecchymosis were measured for the six postsurgical days. Six months after loading, implant survival was assessed. VAS pain score (during the first four postoperative days), rate of NSAID consumption (during the first three postoperative days), and intensity of swelling (during the first five postoperative days) were significantly lower in the test group compared to the control group (All P values < 0.05). One patient in the control group experienced ecchymosis. All implants were successful in function. Application of laser for performing periosteal releasing incision reduced the incidence and severity of postoperative morbidity of the patients undergone implant surgery in conjunction with bone augmentation procedure. We did not find any detrimental effect of laser incision on the implant survival within 6 months of loading.     

Strain driven fast osseointegration of implants

Background

Although the bone's capability of dental implant osseointegration has clinically been utilised as early as in the Gallo-Roman population, the specific mechanisms for the emergence and maintenance of peri-implant bone under functional load have not been identified. Here we show that under immediate loading of specially designed dental implants with masticatory loads, osseointegration is rapidly achieved.

Methods

We examined the bone reaction around non- and immediately loaded dental implants inserted in the mandible of mature minipigs during the presently assumed time for osseointegration. We used threaded conical titanium implants containing a titanium2+ oxide surface, allowing direct bone contact after insertion. The external geometry was designed according to finite element analysis: the calculation showed that physiological amplitudes of strain (500–3,000 ustrain) generated through mastication were homogenously distributed in peri-implant bone. The strain-energy density (SED) rate under assessment of a 1 Hz loading cycle was 150 Jm-3 s-1, peak dislocations were lower then nm.

Results

Bone was in direct contact to the implant surface (bone/implant contact rate 90%) from day one of implant insertion, as quantified by undecalcified histological sections. This effect was substantiated by ultrastructural analysis of intimate osteoblast attachment and mature collagen mineralisation at the titanium surface. We detected no loss in the intimate bone/implant bond during the experimental period of either control or experimental animals, indicating that immediate load had no adverse effect on bone structure in peri-implant bone.

Conclusion

In terms of clinical relevance, the load related bone reaction at the implant interface may in combination with substrate effects be responsible for an immediate osseointegration state.     

Bonding behavior of a glass-ceramic containing apatite and wollastonite in segmental replacement of the rabbit tibia under load-bearing conditions

Glass-ceramic implants containing apatite and wollastonite were studied under load-bearing conditions in a segmental replacement model in the tibia of the rabbit. Alumina-ceramic implants were used as a control. A sixteen-millimeter segment of the middle of the shaft of the tibia was resected at a point distal to the junction of the tibia and the fibula. The defect was replaced by a fifteen-millimeter-long hollow, cylindrical implant that was fixed by intramedullary nailing using a Kirschner wire. Two groups of eight rabbits each (one group with a glass-ceramic implant and the other with an alumina implant) were killed twelve weeks after implantation. Two similar groups were killed twenty-five weeks after implantation. The segment of the tibia that contained the implant was excised and tension-tested. The load to failure of glass-ceramic implants containing apatite and wollastonite increased with time. The loads to failure of the glass-ceramic and alumina implants at twelve weeks after implantation were 19.8 +/- 7.06 and zero newtons, respectively. The loads to failure of glass-ceramic and alumina implants at twenty-five weeks after implantation were 126.4 +/- 32.54 and 19.6 +/- 13.92 newtons, respectively. No glass-ceramic implants broke. A calcium-phosphorus layer at the interface of the glass-ceramic and the bone was observed by scanning electron microscopy and electron-probe microanalysis. There was no interposition of soft tissue between the glass-ceramic and the bone, as observed by Giemsa surface staining.     

Locally delivered rhBMP-2 enhances bone ingrowth and gap healing in a canine model.

The purpose of the present study was to determine if recombinant human bone morphogenetic protein-2 (rhBMP-2) enhances bone ingrowth into porous-coated implants and gap healing around the implants. In the presence of a 3-mm gap between the implant and host bone, porous-coated implants were placed bilaterally for four weeks in the proximal humeri of skeletally mature, adult male dogs. In three treatment groups, the test implant was treated with HA/TCP and rhBMP-2 in buffer at a dose of 100 microg/implant (n=5), 400 microg/implant (n=6), or 800 microg/implant (n=5) and placed in the left humerus. In these same animals, an internal control implant was treated only with HA/TCP and buffer and placed in the right humerus. These groups were compared with a previously reported external control group of seven animals in which no growth factor was delivered [J. Orthop. Res. 19 (2001) 85]. The BMP treated implants in the two lower dose groups had significantly more bone ingrowth than the external controls with the greatest effect in the 100 g/implant group (a 3.5-fold increase over the external control, p=0.008). All three dose groups had significantly more bone formation in the 3-mm gap surrounding the BMP treated implants than the external controls with the greatest effect in the 800 microg group (2.9-fold increase, p<0.001). Thus, application of rhBMP-2 to a porous-coated implant stimulated local bone ingrowth and gap healing. The enhancement of bone formation within the implant (bone ingrowth) was inversely related to dose.     

Experimental studies on splenic autotransplantation in rats

To determine if splenic implants in the body regain vascularization and grow, and to determine the effects of any interaction between implant and remnant on growth of these spleen fragments, we conducted experiments on rats. 1) Spleen fragments were implanted in the omentum (20 cases), in the subcutaneous space (20 cases), or in the liver (10 cases), and the weight of splenic portions and its histological findings were observed 12 and 24 weeks after operation. The best splenic growth was observed in the group of implant in the omentum. 2) Total, 4/5, 2/3, 1/3 and 1/5 spleen were implanted in the omentum and the weight of implants were measured 6 weeks after the operation. The rate of growth of implanted spleen was the highest in the group of 1/5 and was the lowest in the group of whole spleen. 3) Two groups of rats underwent 1/3 splenectomy, and the 1/3 spleen portions was implanted in the omentum. One group had the remaining 2/3 spleen removed, the other group had the remaining 2/3 spleen left in place. In group at 6, 12 and 24 weeks postoperatively the splenic portions was weighed. The implants regenerate with time in rats of both groups. The rate of weight-gain was, however, slow in the group with 2/3 spleen and there was no regeneration on the remaining 2/3 spleen.     

Stimulation of implant fixation by parathyroid hormone (1–34)-A histomorphometric comparison of PMMA cement and stainless steel

Whereas continuous exposure to PTH results in bone resorption, PTH administration at intermittent doses results in bone formation by increasing osteoblast number and activity. PTH leads to faster fracture repair and better fixation of orthopaedic implants in animal models. The present study evaluates if PTH is able to increase the contact surface between bone and implant and whether the effect of PTH is dependent on implant material characteristics. The implants were made as rods, either of stainless steel or Palacos R bone-cement. The steel rods had a surface roughness of R(a) 0.1 microm and the cement rods R(a) 2.2 microm. In 40 adult male rats, one cement rod was inserted in the left tibia and one steel rod in the right tibia. After implantation, the rats were divided into groups by random. One group was injected three times a week with human PTH (1-34) at a dose of 60 microg/kg BW/injection. The second group was injected with the vehicle only. Both groups were then divided into groups for 2 and 4 weeks time till tibial harvest. The tibial segments around the hole of the rods were then prepared by standard histological techniques. The linear tissue surfaces, that had been in contact with the surface of the rod, were analyzed in a blind fashion. PTH increased the bone contact fraction compared with the vehicle in the steel group from 7.4 (SD 7.6) to 21.1 (SD 10.7) % after 2 weeks and from 9.8 (SD 8.1) to 47.1 (SD 13.3) % after 4 weeks. In the cement group PTH increased the contact index again compared with the vehicle from 7.8 (SD 10.2) to 53.6 (SD 26.3) % already after 2 weeks and from 14.3 (SD 15) to 65.6 (SD 15.7) % after 4 weeks. The bone trabeculae adjacent to the implant had become fewer and thicker after the treatment with PTH (1-34), with an increase of the bone mass in the area next to the bone-implant-interface. The earlier onset of PTH effects in the rougher cement group suggests that intermittent PTH treatment might lead to an increased micro-interlock between implant and bone, and might therefore be considered as a possible drug to enhance incorporation of orthopedic implants.