电子束熔融技术制作的个性化根形种植体的制作精度评价

目的：初步评估CBCT结合电子束熔融技术制作的个性化根形种植体的制作误差大小,并分别计算其中CBCT数据提取误差和电子束熔融设备加工误差的大小。方法：分别依据8颗正畸减数离体牙的光学扫描模型和拔牙前CBCT数据提取模型,采用电子束熔融技术制作个性化根形种植体,并建立光学扫描模型,比较个性化根形种植体与离体牙三维偏差的大小。结果：CBCT结合电子束熔融技术制作的个性化根形种植体的整体制作误差为（-0.18±0.04）mm（P〈0.01）,其中EBM设备的加工误差为（-0.20±0.01）mm（P〈0.01）,CBCT数据提取误差为（0.04±0.05）mm。结论：CBCT结合电子束熔融技术制作的个性化根形种植体制作误差较小,主要来自于电子束熔融设备加工误差,并可以通过调节制作参数加以减小。     

基于锥形术CT数字化建模的3D打印牙颌模型制作及精确度研究

目的 基于锥形术CT（CBCT）数据构建患者数字化模型,应用3D打印技术制作牙颌实体模型并评估其精确度。方法 通过Mimics 10.01软件处理正畸临床患者CBCT数据,并结合Geomagic studio三维软件制作牙颌数字化模型,导入MakerBot Replicator2X型3D打印机中,采用熔融沉积技术（FDM）制作聚乳酸材料的上下颌实体模型。比较3D打印模型与传统石膏模型的牙冠近远中径、牙弓长度和宽度及后牙牙尖三角嵴长度测量值。结果 3D打印牙颌模型和传统石膏模型的测量数据经配对样本t检验,无统计学差异（P>0.05）。结论 采用CBCT构建数字化模型具有可行性,能够简化正畸检查流程、实现患者牙颌状况的数字化存储。采用3D打印制作牙颌模型精确度良好,可用于正畸临床。     

结合三维激光扫描的仿真颌骨模型在口腔种植中的应用

目的：探索结合三维激光扫描技术的仿真颌骨模型在口腔种植中的应用。方法：选取就诊于北京大学口腔医院第二门诊部要求种植修复的20例患者,进行口腔颌面锥形束CT（cone beam computed tomography,CBCT）扫描,将扫描后的数据与3D激光扫描数据进行匹配,形成计算机三维颌骨模型并通过三维快速成型机形成实物的三维颌骨模型。术者在此模型上进行术前设计和模拟,制作手术导板。完成种植修复。结果：20例患者中12例颌骨的锥形束CT数据与三维激光扫描数据匹配准确;制作出手术导板,并在手术导板引导下顺利完成手术及最终修复。3例CBCT数据与激光扫描模型配比后发现CBCT在后牙区有偏差,最大偏差1mm。5例患者缺牙区骨质形态与临床不符,骨缺损范围偏大。结论：结合激光扫描技术的仿真颌骨模型在牙列区有清晰外形同时真实的显示了颌骨形态,为医生提供了一个熟悉而真实的模拟空间。     

3D打印铝合金种植手术导板准确度的体外评价

目的 在体外树脂模型上设计并模拟种植体植入实验，分析比较一种新型铝合金材质种植导板与传统树脂导板的准确度差异。方法 选取一名肯氏III类牙列缺损患者并制取硅橡胶印模，灌制超硬石膏模型后使用口内扫描仪扫描，设计并打印20个树脂模型。将患者的锥束计算机断层扫描（CBCT）数据导入软件（3Shape Implant Studio 2019）并规划该患者的种植方案，设计种植导板。使用3D打印机分别制作树脂与铝合金材质手术导板各一个。通过全程引导手术将种植体植入模型中，植入后拍摄术后CBCT。在软件中测量术后CBCT图像与原治疗计划图像，在近远中面和唇腭面分析种植体相对于原设计在三维线性以及角度上的准确度差异。结果 种植体在金属导板引导下的线性偏差分别为近中（0.51±0.63）mm，远中（0.49±0.58） mm，唇向（1.14±1.40） mm，腭向（1.15±1.42） mm；垂直向（2.09±0.84） mm。近远中角度和唇腭侧角度的角度偏差分别为（1.41°±0.81°）和（1.78°±1.03°）。种植体在垂直向的偏差与近远中角度、唇腭侧角度偏差与树脂导板引导下的种植体偏差有统计学...     

CAD/CAM导板在后牙区种植精度的体外研究

目的 后牙区利用计算机辅助设计和制作（computer aided design and computer aided manufacture,CAD/CAM）导板种植时,比较翻瓣与不翻瓣两种术式的精度。方法 选取20名后牙种植患者的锥形束CT（cone beam CT,CBCT）资料和石膏模型,采用3D打印技术制作翻瓣与不翻瓣树脂模型,运用导板在两种模型上模拟牙种植术,分别计算术前术后种植体位置偏差进而比较两种术式的精度。结果 CAD/CAM导板在后牙区辅助种植时,翻瓣与不翻瓣术式种植体顶端偏差分别为（0.95±0.36）mm、（1.33±0.43）mm;底端偏差分别为（1.53±0.56）mm、（1.94±0.30）mm;角度偏差分别为3.45°±1.10°、3.31°±1.55°;深度偏差分别为（0.75±0.47）mm、（1.43±0.41）mm。翻瓣与不翻瓣两种术式在种植体距离偏差上有统计学差异,角度偏差上没有统计学差异。结论 CAD/CAM导板引导的种植翻瓣术式比不翻瓣术式在种植体距离偏差上更准确。     

数字化导板辅助种植6颗平行种植体精确度分析

目的 通过对比3种数字化测量方法,评估静态导板辅助种植的精确度并探讨同一导板辅助种植多颗种植体的影响误差及种植体之间的平行情况。方法 随机抽取3名下颌无牙颌患者的CBCT数据,数据提取后通过Straumann P20+3D打印机仿形态各打印10个模型,共30个下颌无牙颌树脂模型。按照无牙颌固定修复在46位点、44位点、42位点、32位点、34位点、36位点常规植入6颗平行种植体,并设计手术导板。由1名种植医生从46位点开始依次顺序种植6颗种植体,共180颗种植体,术后分别用3种测量方法评估植入种植体的3D距离偏差及轴向角度偏差。结果 术后种植体合计平均角度偏差为1.89°±0.87°,平均3D距离偏差颈部为（0.46±0.19）mm、根方为（0.58±0.21）mm;扫描杆&Qualify、扫描杆&coDiagnostiX和CBCT&coDiagnostiX 3种测量方法的测量数据轴向角度偏差分别为1.96°（1.26°）、1.82°（1.15°）和1.60°（1.12°）,颈部3D距离偏差分别为0.37mm(0.23mm)、0.41mm(0.15mm)和0.6...     

一种通用型口腔种植定位器的体外实验研究

目的　通过体外实验评估一种通用型口腔种植定位器的测量和导向功能。方法    以猪下颌骨的无牙区域作为缺牙区牙槽嵴模型。分别应用锥形束CT（cone beam computed tomography,CBCT）、定位器和游标卡尺测量牙槽嵴颊舌向宽度,以游标卡尺测量结果为标准,比较CBCT和定位器的测量偏差值。分别使用定位器引导种植备洞（定位器组）和自由手种植备洞（自由手组）,应用CBCT测量比较两组备洞方向的角度偏差值和距离偏差值,以评估两组侧穿风险差异。结果　（1）测量牙槽嵴颊舌向宽度：定位器的测量偏差值［（1.24 ± 0.491）mm ］稍大于CBCT测量偏差值［（0.81 ± 0.377）mm ］,差异有统计学意义（P = 0.025）。（2）种植备洞方向准确性分析：定位器组的角度偏差（6.05° ± 2.803°）和距离偏差［（1.05 ± 0.302）mm ］分别小于自由手组的角度偏差（20.50° ± 7.199°）和距离偏差［（3.70 ± 0.971）mm ］,差异均有统计学意义（均P < 0.05）。结论    本研究的通用型口腔种植定位器兼具牙槽骨颊舌向宽度测量和辅助口腔种植导向功能,尽管存在一定测量误差,但可以满足临床需求。     

探究后牙区拟种植位点牙槽嵴顶CBCT影像的判读误差

目的:探究后牙区拟种植位点拔牙3个月后,牙槽嵴顶CBCT影像边界不连续伴模糊时的显影误差。方法:选择2022年4～9月就诊于徐州医科大学附属口腔医院种植中心,主诉后牙区单牙拔除后3个月,且CBCT检查显示缺牙区牙槽嵴顶影像不连续伴模糊的40例患者纳入研究。试验组使用医学三维重建软件所提供的骨阈值自动分割功能,提取拟种植位点牙槽骨影像的2D蒙版,对照组采用人工判读的方法,提取拟种植位点牙槽骨影像的2D蒙版。最后,基于2D蒙版三维重建出术区牙槽骨的三维数字化模型,并与术中所获取的牙槽嵴顶光学模型进行三维比较,运用偏差分析算法计算出二者间差异的平均偏差(AVG)与均方根值(RMS)。结果:试验组拟种植位点牙槽嵴顶的CBCT重建模型与术中光学扫描模型间差异的AVG与RMS分别为(2.26±0.36) mm和(2.35±0.26) mm,均大于对照组[AVG为(1.25±0.21) mm, RMS为(1.31±0.20) mm],且差异具有统计学意义(P<0.05)。结论:拔牙3个月后,当牙槽嵴顶的CBCT影像不连续伴模糊时,人工判读的牙槽嵴顶位置,其误差小于经软件自动判读得到的结果,并且...     

种植数字化印模精确度分析

目的：测试种植数字化印模的精确度,为种植数字化修复提供参考。方法：随机选取115例种植患者,待骨结合形成后放置种植转移杆,拍摄锥形束CT（CBCT）,同时进行口腔扫描,制作3D打印数字化种植模型,对数字化树脂模型进行模型扫描,得到模型数据,以余留牙为参考依据,在Nobel Clinicion软件中匹配。结果：患者CBCT中种植体转移杆与数字化模型上的种植体转移杆面、冠状面、矢状面均完全匹配重叠,提示口腔内的种植体位置、方向、角度与口腔扫描制取的数字化模型上的替代体完全一致。结论：口腔扫描打印的3D数字化树脂模型完全准确,可在临床上推广运用。     

3D打印种植导板在前牙区不同术式的精度比较

目的 比较3D打印种植导板引导前牙牙种植在不同术式下的精度。方法 选择21例（32个牙位）牙缺失患者,制作仿真翻瓣与不翻瓣颌骨模型,分为翻瓣组（FP组）与不翻瓣组（FPS组）,分别设计制作牙种植导板,比较两组牙种植体实际位置与术前规划在顶端、底端、垂直向距离的偏差值和角度偏差值。采用SPSS 19.0软件对数据进行统计学分析。结果 FPS组与FP组种植体顶端、底端、垂直向距离偏差值和角度偏差值的差异均有统计学意义（P<0.05）;与FPS组相比,FP组偏差值更小,精度更高。结论 3D打印种植导板可提高牙种植的精确性,翻瓣与不翻瓣的不同术式对牙种植精度有一定的影响,临床医生可根据实际情况合理选择术式。     

Accuracy of a chairside fused deposition modeling 3D-printed single-tooth surgical template for implant placement: An in vitro comparison with a light cured template

PurposeTo compare the accuracy of a chairside fused deposition modeling (FDM) 3D-printed surgical template with that of a light-cured template for implant placement.Materials and methodsTwenty standard mandibular resin models with missing teeth 36 and 46 were selected. Surgical templates were fabricated using a chairside FDM 3D-printer (test group) or a light-curing 3D printer (control group) (n = 20/group). Forty implants were placed by a clinician blinded to group allocation. The angular, 3D, mesiodistal, buccolingual, and apicocoronal deviations at the implant base and tip between preoperative design and postoperative implant position were recorded.ResultsThe mean angular (test vs control groups: 3.22° ± 1.55° vs 2.74° ± 1.24°, p = 0.343) and 3D deviations at the implant base (test vs control groups: 0.41 ± 0.13 mm vs 0.35 ± 0.11 mm, p = 0.127) and tip (test vs control groups: 0.91 ± 0.34 mm vs 0.75 ± 0.28 mm, p = 0.150) were similar. The mesiodistal, buccolingual, and apicocoronal deviations at the implant base and tip also did not differ significantly between groups (p > 0.05).ConclusionsFor single tooth gap indications, implant placement with an FDM 3D-printed surgical template was as accurate as that with a light-cured template, and more efficient.     

Conventional Multi‐Slice Computed Tomography (CT) and Cone‐Beam CT (CBCT) for Computer‐Aided Implant Placement. Part II: Reliability of Mucosa‐Supported Stereolithographic Guides

Purpose: Deviations of implants that were placed by conventional computed tomography (CT)‐ or cone beam CT (CBCT)‐derived mucosa‐supported stereolithographic (SLA) surgical guides were analyzed in this study. Materials and Methods: Eleven patients were randomly scanned by a multi‐slice CT (CT group) or a CBCT scanner (CBCT group). A total of 108 implants were planned on the software and placed using SLA guides. A new CT or CBCT scan was obtained and merged with the planning data to identify the deviations between the planned and placed implants. Results were analyzed by Mann‐Whitney U test and multiple regressions (p < .05). Results: Mean angular and linear deviations in the CT group were 3.30° (SD 0.36), and 0.75 (SD 0.32) and 0.80 mm (SD 0.35) at the implant shoulder and tip, respectively. In the CBCT group, mean angular and linear deviations were 3.47° (SD 0.37), and 0.81 (SD 0.32) and 0.87 mm (SD 0.32) at the implant shoulder and tip, respectively. No statistically significant differences were detected between the CT and CBCT groups (p = .169 and p = .551, p = .113 for angular and linear deviations, respectively). Conclusions: Implant placement via CT‐ or CBCT‐derived mucosa‐supported SLA guides yielded similar deviation values. Results should be confirmed on alternative CBCT scanners.     

Accuracy assessment of cone beam computed tomography-derived laboratory-based surgical templates on partially edentulous patients

Objectives: The aim of the present prospective clinical study was to evaluate the match between the positions and axes of the virtually planned and the placed implants using laboratory‐based surgical guides generated from cone beam computed tomography (CBCT). Materials and methods: A total of 132 implants were placed with the aid of 3D‐based transfer templates in 52 consecutive partially edentulous patients between April 2008 and March 2010. After individual adaptation of the scan templates and CBCT scanning, the acquired data for virtual implant planning and simulation were processed using the med3D software program. After finalizing the virtual placement of the implants the radiographic templates were converted into operative guides containing titanium sleeves for cavity preparation. Preoperative planning was merged with postoperative CBCT data to identify linear and angular deviations between virtually planned and placed implants. Results: Compared with the planned implants the installed implants showed linear deviations in the median at the neck and apex of 0.27 mm (range 0.01–0.97 mm), and of 0.46 mm (range 0.03–1.38 mm), respectively. The angle deviation was 1.84° in median, with a range of 0.07–6.26°. The extent of deviation depends on the size of the tooth gap and the distribution of the remaining teeth. Conclusion: The results of this study suggested that laboratory‐fabricated surgical guides using CBCT data may be reliable in implant placement under prosthodontic considerations in partial edentulism. To cite this article:
Behneke A, Burwinkel M, Knierim K, Behneke N. Accuracy assessment of cone beam computed tomography‐derived laboratory‐based surgical templates on partially edentulous patients.
Clin. Oral Impl. Res. 23 , 2012; 137–143.
doi: 10.1111/j.1600‐0501.2011.02176.x     

Accuracy of three-dimensional printed models derived from cone-beam computed tomography

ObjectivesTo determine the accuracy of three-dimensional (3D) printed models fabricated from cone-beam computed tomography (CBCT) scans of human mandibular dry skulls in comparison with models derived from intraoral scanner (IOS) data.Materials and MethodsSix human mandibular dry skulls were scanned by IOS and CBCT. Digital models (DMs) constructed from the IOS and CBCT data were fabricated physically using a 3D printer. The width and thickness of individual teeth and intercanine and molar widths were measured using a digital caliper. The accuracy of the DMs was compared between IOS and CBCT. Paired t-tests were used for intergroup comparisons.ResultsAll intraclass correlation coefficient values for the three measurements (mesial-distal, buccal-lingual, width) exceeded 0.9. For the mandibular teeth, there were significant discrepancies in model accuracy between the IOS (average discrepancies of 0.18 ± 0.08 mm and 0.16 ± 0.12 mm for width and thickness, respectively) and CBCT (0.28 ± 0.07 mm for width, 0.37 ± 0.2 mm for thickness; P < .01). Intercanine (P = .38) and molar widths (P = .41) showed no significant difference between groups.ConclusionsThere was a statistically significant difference in the accuracy of DMs obtained from CBCT and IOS; however, this did not seem to result in any important clinical difference. CBCT could be routinely used as an orthodontic diagnostic tool and for appliance construction.     

数字化导板引导下全口种植即刻负重可行性与精准度的研究

目的 探究数字化导板引导下全口种植即刻负荷的可行性,根据影像学数据评价导板引导的种植精准度,探讨可能影响植体位置精度的相关因素.方法 按照准入排除标准,收集2017年至2019年使用数字化导板引导下的全口种植即刻负重固定修复患者16例(98枚植体),跟踪随访患者评价长期的临床修复效果.利用CBCT数据测量30颗植体实际...     

3D打印导板在上前牙种植中的精度评价

目的:评价3D打印导板在上前牙种植的精确度,探讨其临床效果。方法:选取2017年6月—2018年6月在青岛大学附属医院口腔种植科行上前牙区种植手术的60例患者,采用随机数字表法随机分为G组（导板组）和R组（常规组）,每组30例,均在术前拍摄锥形束CT（CBCT）,应用“Dentiq Guide种植导板软件”进行设计。G组制作3D打印导板辅助种植手术,R组行常规种植手术。术后即刻拍摄CBCT,应用“Dentiq Guide种植导板软件”将术前、术后CT重叠,测量术前设计与种植体实际位置差异,采用SPSS 24.0软件包对所得数据进行统计分析。结果:G组共植入46颗种植体,测量偏差角度(2.34±1.03)°,顶部(0.63±0.38)mm,根尖部(0.71±0.38)mm,深度(0.41±0.40)mm;R组共植入43颗种植体,测量偏差角度(6.72±3.65)°,顶部(1.59±0.35)mm,根尖部(2.05±0.92)mm,深度(0.77±0.63)mm。2组在角度、顶部、根尖部、深度的差异均有统计学意义（P<0.05）。结论:应用3D打印导板辅助上前牙种植手术,可提高手术精确度,满足种植修复需要,践行以修复为导向的精确种植理念。