一段式叶状钛牙种植体骨内种植的临床研究

作者自1992年开始开展了一段式叶状钛牙种植体骨内种植的临床研究工作，至今随访已超过三年的为138例患者，205颗种植体，拔除16颗，其中因种植体折断而拔除的4颗，其成功率为92．2％。本文对其手术方法、成功因素、一段式种植体的优点等进行了分析和讨论。作者认为一段式叶状钛牙种植体是一种值得推广的种植体。     

叶状种植体在前牙种植中的临床应用

目的：探讨CDIC纯钛一段式叶状种植体在前牙缺失种植中的应用效果。方法：对128例失牙患者共种植CDIC纯钛一段式叶状种植体152枚，术后6个月行烤冠修复。结果：修复后通过1－5年随访，种植体成功率为97．37％。结论：CDIC纯钛一段式叶状种植体在前牙种植修复中具有成功率高，操作简便，创伤小的优点。严格的适应症，精细的外科操作，正确的修复是种植成功的关键。     

种植体-天然牙支持的种植义齿修复的临床研究

了解种植体－天然牙联合支持地联冠或桥在一段式种植体修复中的临床效果。方法：用常规手术方法植入一段式纯钛螺旋状种植体,经愈合期后,采用种植体一天然牙支持的烧 或联冠修复缺失牙。结果５５枚种植体行使功能良好,五年成功率达到９４．５５％。     

816枚人工牙种植体外科植入手术问题探讨

牙种植外科技术是种植学的重要组成部分，它直接关系到牙种植的成功与失败。我们１９９３-１９９７年共种植８１６枚人工种植牙,取得了满意的临床效果。本文就作者的临床体会对种植手术的设计、术前准备、手术注意事项等问题进行分析探讨。１材料与方法１．１种植体共采用了７种类型种植体共８１６枚,分别为:（１）ＣＤＩＣ(卫生部种植科技中心)锥状螺旋种植体３０１枚;（２）ＣＤＩＣ叶状种植体６枚;（３）丽珠羟基磷灰石喷涂二段种植体２３枚;（４）西湖二段种植体７５枚;（５）ＨＢＩＣ(河北医科大学厚朴口腔种植科技中心)一段式种植体２…     

CDIC非埋植型钛锥状螺旋牙种植体骨内种植的临床效果评价

67例患者共植入CDIC非坦植型钛锥状螺旋牙种植体98枚，临床观察18－48个月。结果表明：本组资料的累计成功率为93．9％。牙种植你丢失主要发生在愈合初期，失败率不随观察时间的延长而增加。单一牙种植体的单冠修复失败率较高。采用种植体一天然牙联合固定桥修复者成功率较高。CDIC非埋植型钛锥状螺旋牙种植体是一种适合国人前牙修复的理想牙种植体。     

120例人工种植牙的临床效果分析

目的：对120例患者实施了262枚人工种植牙修复治疗,观察远期的效果。方法：应用纯钛种植体等多种种植体修复牙列缺损。结果：经追随访观察11～16年,对120例患者共植牙262枚,其中成功240枚,失败22枚,成功率达91．6％。结论：种植体选择得当、适用症选择得当、修复技术操作规范、可获得良好的种植修复效果。     

微孔钛种植体的实验研究及临床应用

作者报导微孔钛种植体的实验研究及临床应用。实验中证明国产微孔钛性能良好,骨组织长入微孔间隙深度及其与牙槽骨的结合力皆与国外资料相似,临床应用种植体修复后的病例最长已超过5年。但本组病例数不多,少数病例仍有受(牙合)力的影响或局部感染的因素而致失败,故还须继续探索改进。     

3D打印和CAD/CAM氧化锆种植体骨结合性能的动物实验评价

目的 比较3D打印和计算机辅助设计与制造(CAD/CAM)氧化锆种植体与纯钛种植体在动物体内的骨结合和成骨效果的差异,评价氧化锆种植体骨结合性能.方法 分别将3D打印氧化锆、CAD/CAM种植体和钛种植体各20枚随机植入6只Beagle犬的胫骨内,8周后观察氧化锆种植体的成功率和骨结合能力,并与钛种植体进行比较,观察指...     

CDIC叶状钛种植体临床应用体会

作者采用国产叶状钛种植体对41名患者口内缺牙区作了48颗种植术，观察12－46个月，均已完成冠修复，除2例失败外，均获成功，作者总结了临床应用的体会，并就种植术应注意的问题，叶状钛种植体临床应用的体会，并就种植术应注意的问题，叶状钛种植体临床应用的特点及种植失败原因进行了分析。     

放疗对狗下颌纯钛种植体与骨接触作用的影响

目的:观察放疗对狗下颌纯钛种植体与骨接触作用的影响。方法:8只成年雄性杂种狗,拔除双侧下颌第3、4前磨牙和第1磨牙,形成无牙区。拔牙后3个月,用电子直线加速器照射一侧下颌无牙区,单一剂量15Gy。另一侧不接受照射,作为对照。放疗后3个月,狗双侧下颌无牙区各植入纯钛种植体4枚,其中两枚种植体无任何辅助治疗措施。种植术后1.5个月和3个月分别处死2只动物取材。结果:放疗侧种植体的种植体-骨接触率与对照侧相比,有明显下降,在统计学上有显著差异(P=0.0001<0.01);放疗后种植体周围骨小梁体积百分比具体数值下降,统计学上差异不明显(P=0.071>0.05)。结论:放疗会影响狗下颌纯钛种植体与骨的接触作用。     

A comparison of 3 different endosseous nonsubmerged implants in edentulous mandibles: a clinical report.

The purpose of this prospective clinical study was to investigate the outcome of 3 different types of endosseous, nonsubmerged implants in the anterior part of the mandible. Fourteen older edentulous patients, 10 females and 4 males, were included. All participants received 3 different types of endosseous implants in the anterior mandible: 1 titanium plasma-sprayed cylindric implant (4 mm in diameter), 1 titanium cylindric implant with hydroxyapatite (HA) coating (4 mm in diameter), and 1 standard threaded titanium implant (3.75 mm in diameter). The 3 types of implants were originally designed to be placed in a 2-step surgical procedure. However, at this stage all implants were simultaneously provided with a temporary abutment that penetrated the mucosa. Three months later the temporary abutments were replaced by ball abutments, which were connected to an overdenture. At 12, 24, and 36 months after surgery, marginal bone resorption and Periotest values were recorded. Two patients died within the 2 first postoperative years. Five of 42 implants (11.9%) failed to osseointegrate. After 3 years, marginal bone resorption around titanium plasma-sprayed implants was significantly greater than that seen around both HA-coated and threaded titanium implants. Threaded titanium implants also had significantly better scores for marginal bone resorption than the HA-coated implants. Periotest values for HA-coated cylinders were significantly lower than test values for the other implants after 3 years (P < .05). The conclusion from this investigation is that nonsubmerged implants showed impaired prognoses compared to implants placed according to the 2-stage concept. Marginal bone resorption around titanium plasma-sprayed cylindric implants was clearly increased compared to the 2 other implant systems. Periotest values for HA-coated cylindric implants were superior to titanium plasma-sprayed and pure titanium implant surfaces.     

Effects of overdenture attachment systems with different working principles on stress transmission: A three-dimensional finite element study

PURPOSEThe aim of the present study was to compare the stress distributions on the dental implants, abutments, and bone caused by different overdenture attachment types under functional chewing forces.MATERIALS AND METHODSThe 3D finite element models of the mandible, dental implants, attachment types, and prostheses were prepared. In accordance with a conventional dental implant supported overdenture design, the dental implants were positioned at the bone level in the canine teeth region bilaterally. A total of eight models using eight different attachment systems were used in this study. All the models were loaded to simulate chewing forces generated during the centric relationship (450 N), lateral movement (400 N), protrusive movement (400 N), and also in the presence of a food mass unilaterally (200 N). Stress outputs were obtained as the maximum principal stress and the equivalent von-Mises stress.RESULTSIn all attachment types, higher stress values were observed in the abutments, dental implants, and bone in the magnet attachments in different loading conditions. The highest stress values were observed among the magnet systems in the components of the Titanmagnetics model in all loading conditions (stresses were 15.4, 17.7, and 33.1 MPa on abutment, dental implant, and bone, respectively). The lowest stress value was observed in the models of Zest and O-Ring attachments.CONCLUSIONThe results of the present study implied that attachment types permitting rotation and tolerating various angles created lower stresses on the bone, dental implants, and abutments.     

The removal torque of titanium implant inserted in rabbit femur coated with biomimetic deposited Ca-P coating

A number of experimental data on biomimetic deposition CaP (BDCaP) coating implants have reported promising outcomes by histological evaluation. But little is investigated on the role of the BDCaP coating and osseointegration mechanism by interface shear strength. To make a direct biomechanical comparison between the BDCaP coating implants and the uncoated rough titanium implants (control), a well-established animal model for implants removal torque testing was employed in rabbits, using a self-matching experimental design. All implants had an identical cylindrical screw shape without any macroscopic retentive structure. After 2, 4, 6, 8 and 12 weeks of bone healing, removal torque testing was performed to evaluate the interfacial shear strength of each implant type. The torqued implants were sputter-coated with gold for morphology observation and observed with a field-emission electron microscopy. Results showed that the interfacial shear strength of the BDCaP coating implants was similar to that of the uncoated rough implants at 2 and 4 weeks of healing. The mean removal torque values of the BDCaP coating implants were lower than those of control implants (P < 0.05) after 6 weeks of healing. The removal torque values for both types of implants revealed similar mean values after 8 and 12 weeks of healing; there were no significant difference between the two types of implants (P > 0.05). It can be concluded that the BDCaP coating implants had no beneficial effect on the interfacial shear strength at early bone healing stage.     

In vivo force measurements on maxillary implants supporting a fixed prosthesis or an overdenture: a pilot study

STATEMENT OF PROBLEM: In this preliminary study, an attempt was made to measure in vivo forces simultaneously on 5 maxillary implants with different types of superstructure. MATERIAL AND METHODS: Force measurements were carried out on 1 test patient with 5 ITI implants in the edentulous maxilla. A screw-retained fixed complete denture and an overdenture were fabricated for comparative measurements of forces. The overdenture could be mounted to 2 different types of bars. The measuring method was used with piezo-electric force transducers that were directly mounted onto the implants. This allowed for simultaneous measurements of forces in 3 dimensions, ie, in axial and transverse directions. Static and functional forces such as maximum biting (clenching), biting on a bite plate, and chewing food were registered. All measurements were repeated in the same way 2 years later. RESULTS: The registered forces exhibited similar force patterns with both types of superstructure and both types of bars for overdenture connection. The force magnitudes were significantly different for the 3 dimensions (P<.05) with highest forces along the implant axis. On the posterior implants, force magnitudes were significantly higher (P<.05) than on the anterior implants in all 3 dimensions. On the anterior implants, under some test conditions, the transverse force components reached up to 100% of the axial force or even exceeded it during the chewing of food. During maximum biting, no upward force (tensile force) was found on any implant with the fixed complete denture, but upward force was found on one anterior implant with the overdenture. When chewing food, small force magnitudes in upward directions were regularly found with both superstructures. The force patterns between the first and second registrations showed similar trends, and no obvious differences were found. CONCLUSION: From these results it was concluded that similar patterns of force transmission onto the implants are observed with a fixed complete denture and an overdenture connected to maxillary implants. The bar design did not significantly influence the force pattern.     

Osseointegration of zirconia and titanium dental implants: a histological and histomorphometrical study in the maxilla of pigs

Objectives: The purpose of the present study was to histologically compare the bone tissue responses to surface-modified zirconia and titanium implants.
Methods: Threaded zirconia implants were produced using a new low-pressure injection moulding technique and thereafter surface treated by acid etching. Titanium implants with the exact shape and surface treated by sandblasting and acid etching (SLA) served as controls. Fifteen adult pigs received both implant types in the maxilla 6 months after extraction of the second and third incisors. The animals were sacrificed after 4, 8 and 12 weeks and 30 implants with surrounding bone were retrieved.
Results: Histological evaluation showed osseous integration for both materials. Zirconia implants revealed mean peri-implant bone density values of 42.3% (SD ± 14.5) at 4 weeks, 52.6% (SD ± 5.7) at 8 weeks and 54.6% (SD ± 11.5) at 12 weeks after implantation, whereas Ti-SLA implants demonstrated mean values of 29% (SD ± 10), 44.1% (SD ± 18) and 51.6% (SD ± 8.6) at corresponding time intervals. With respect to the bone–implant contact ratio, the mean values for zirconia ranged between 27.1% (SD ± 3.5) and 51.1% (SD ± 12.4) and for Ti-SLA, it ranged between 23.5% (SD ± 7.5) and 58.5% (SD ± 11.4).
For the parameters investigated, no statistically significant differences between both types of implants could be detected at any time point.
Conclusions: No statistical difference between implants could be demonstrated with any of the methods used. The limited number of animals per group, however, does not allow to conclude that there is no difference in osseointegration between the two types of implants, although the data tend to suggest such a trend.     

Spontaneous progression of ligatured induced peri-implantitis at implants with different surface characteristics. An experimental study in dogs II: histological observations

Aim: The aim of the present study was to analyze tissue reactions to plaque formation following ligature removal in experimental peri-implantitis at commercially available implants in dogs.
Material and methods: Mandibular premolars and the three anterior premolars in both sides of the maxilla were extracted in six Labrador dogs. After 3 months, four implants representing four different implant systems – groups A (turned), B (TiOblast), C (SLA), D (TiUnite) – were placed in a randomized order in the right side of the mandible. Three months after implant installation, experimental peri-implantitis was initiated by placement of ligatures and plaque formation. The ligatures were removed when about 40–50% of the supporting bone was lost. After the subsequent 24-week period of continued plaque accumulation, block biopsies containing implants and their surrounding tissues were obtained and prepared for histological analysis.
Results: All types of implants exhibited extensive inflammatory cell infiltrates and large associated crater-formed osseous defects. The lesions were consistently characterized by insufficient encapsulation of pus and biofilm layers and the inflammatory cell infiltrates extended apical of the pocket epithelium. The presence of numerous osteoclasts indicated active tissue destruction. The vertical dimension and the overall surface area of the infiltrated connective tissue (ICT) were larger at implants of group D than at other implant types.
Conclusion: It is suggested that spontaneous progression of peri-implantitis is associated with severe inflammation and tissue destruction.     

Evaluation of combinations of titanium, zirconia, and alumina implants with 2 bone fillers in the dog

The quality of the tissue-implant interface was evaluated using light and scanning electron microscopy with morphometric analysis. Nine dogs were implanted with 3 types of dental implants (titanium, zirconia, or alumina). A total of 24 dental implants was placed in mandibular bone previously filled with coral carbonate calcium (corail) or hydroxyapatite. The study results in breaking the concept of osseointegration into 2 phases: "osseocoaptation," which concerns only the interface (physical contact between the implants and the bone without interpenetration process), and "osseocoalescence," which relies on an interpenetration of the bioactive material, which almost entirely disappears, being substituted by newly formed bone. There was no significant statistical difference between the 3 types of implants. Both fillings showed good ossecoalescence properties. However, hydroxyapatite led to fibrous encystment, preventing osseocoaptation of implants. In contrast with calcium carbonate filling.     

The early remodeling phases around titanium implants: a histomorphometric assessment of bone quality in a 3- and 6-month study in sheep

The purpose of this study was to evaluate the quality of the bone matrix around commercially pure titanium implants at 3 and 6 months postplacement in sheep. Implants were placed in the corticotrabecular areas of both femurs in 6 animals. Each animal received 4 Euroteknika implants in the right femur and 4 Nobel Biocare implants in the left femur. Bone blocks containing the implants were studied undecalcified after being embedded in methylmethacrylate. Sections were stained with toluidine blue and basic fuchsin. The amount of bone around the implants, the contact interface between the implant and bone, and the mineral apposition rates were measured. The fractional amount of woven bone could be quantified because of its high glycosaminoglycan content. No differences could be observed between the 2 types of implants. Total bone volume did not increase around both types of implants between 3 and 6 months, indicating that ankylosis was rapidly achieved. In contrast, in the area in contact with the implant, the bone-titanium interface drastically increased and the mineral apposition rate decreased. The fractional volume of woven bone around implants was considerably reduced after 6 months. Bone quality around implants was improved at 6 months (volume of woven bone near zero), and true osteonic structures were observed in close contact with titanium. The remodeling process appeared to improve bone quality and increase the bone-titanium interface around implants, while the net bone quantity necessary to immobilize implants was achieved rapidly and remained unchanged.     

Crestal bone changes around titanium implants. A histometric evaluation of unloaded non-submerged and submerged implants in the canine mandible

BACKGROUND: Today, implants are placed using both non-submerged and submerged approaches, and in 1- and 2-piece configurations. Previous work has demonstrated that peri-implant crestal bone reactions differ radiographically under such conditions and are dependent on a rough/smooth implant border in 1-piece implants and on the location of the interface (microgap) between the implant and abutment/restoration in 2-piece configurations. The purpose of this investigation was to examine histometrically crestal bone changes around unloaded non-submerged and submerged 1- and 2-piece titanium implants in a side-by-side comparison. METHODS: A total of 59 titanium implants were randomly placed in edentulous mandibular areas of 5 foxhounds, forming 6 different implant subgroups (types A-F). In general, all implants had a relatively smooth, machined coronal portion as well as a rough, sandblasted and acid-etched (SLA) apical portion. Implant types A-C were placed in a non-submerged approach, while types D-F were inserted in a submerged fashion. Type A and B implants were 1-piece implants with the rough/smooth border (r/s) at the alveolar crest (type A) or 1.0 mm below (type B). Type C implants had an abutment placed at the time of surgery with the interface located at the bone crest level. In the submerged group, types D-F, the interface was located either at the bone crest level (type D), 1 mm above (type E), or 1 mm below (type F). Three months after implant placement, abutment connection was performed in the submerged implant groups. At 6 months, all animals were sacrificed. Non-decalcified histology was analyzed by evaluating peri-implant crestal bone levels. RESULTS: For types A and B, mean crestal bone levels were located adjacent (within 0.20 mm) to the rough/smooth border (r/s). For type C implants, the mean distance (+/- standard deviation) between the interface and the crestal bone level was 1.68 mm (+/- 0.19 mm) with an r/s border to first bone-to-implant contact (fBIC) of 0.39 mm (+/- 0.23 mm); for type D, 1.57 mm (+/- 0.22 mm) with an r/s border to fBIC of 0.28 mm (+/- 0.21 mm); for type E, 2.64 mm (+/- 0.24 mm) with an r/s border to fBIC of 0.06 mm (+/- 0.27 mm); and for type F, 1.25 mm (+/- 0.40 mm) with an r/s border to fBIC of 0.89 mm (+/- 0.41 mm). CONCLUSIONS: The location of a rough/smooth border on the surface of non-submerged 1-piece implants placed at the bone crest level or 1 mm below, respectively, determines the level of the fBIC. In all 2-piece implants, however, the location of the interface (microgap), when located at or below the alveolar crest, determines the amount of crestal bone resorption. If the same interface is located 1 mm coronal to the alveolar crest, the fBIC is located at the r/s border. These findings, as evaluated by non-decalcified histology under unloaded conditions, demonstrate that crestal bone changes occur during the early phase of healing after implant placement. Furthermore, these changes are dependent on the surface characteristics of the implant and the presence/absence as well as the location of an interface (microgap). Crestal bone changes were not dependent on the surgical technique (submerged or non-submerged).     

Bone healing capacity of titanium plasma‐sprayed and hydroxylapatite‐coated oral implants

The influence of surface quality, in particular surface topography and implant material, was evaluated by inserting titanium‐ and hydroxylapatite plasma‐sprayed coated implants into the maxilla of 10 goats. Three types of plasma‐spray coatings were applied to tapered, screw shaped implants; titanium plasma‐spray coating (TPS), titanium plasma‐spray coating with additional acid passivation (TPSA) and a bilayered coating (TPS/HA) consisting of titanium plasma‐spray coating (TPS) and a hydroxylapatite part (HA). In addition, as machined implants (TIM) were used as control. A total of 40 implants were inserted according a balanced split plot design. At the end of a 3‐month healing period, it appeared that 5 implants (2 TPS, 1 TPSA, 1 TPS/HA and 1 TiM) were lost. Histological examination revealed a stronger bone response to TPS/HA coated implants. Even the TPS/HA coated implants induced bone formation on the part of the implant inserted into the sinus. No signs of delamination of the TPS coatings were visible. The HA part of the dual coating showed signs of degradation. Histomorphometrical analysis confirmed these findings. A significant difference in bone contact ( P <0.05) was measured between the TPS/HA coated implants and the other types of implants. Linear regression ( r >0.2) showed no correlation between the inscrew values at the base line and the bone contact measurements 3 months after healing. On the basis of these results, we can conclude that the chemical composition of the HA coating has a positive influence on the bone reaction. The influence of roughness is less evident.