Becker W, Becker B E, Ricci A, Bahat O, Rosenberg E, Rose L F, Handelsman M, Israelson H
Department of Periodontology, University of Southern California School of Dentistry, Los Angeles, California, USA.
Clin Implant Dent Relat Res. 2000;2(3):159-65. doi: 10.1111/j.1708-8208.2000.tb00007.x.
Brånemark fixtures were originally placed in two stages, whereas titanium plasma-sprayed (TPS) solid-screws are placed in one stage. Long-term survival rates for both types of implants are excellent. Excellent survival rates have also been reported for machined screw-shaped (MS) titanium implants placed in one stage. A small number of studies have compared different implant systems and methods of implant placement.
The purpose of this study is to report clinical outcomes from a prospective longitudinal, multicenter study comparing Brånemark MS fixtures (Nobel Biocare, Yorba Linda, California, USA) placed in either one or two stages with a one-stage TPS system (ITI Straumann, Waldenburg, Switzerland).
A protocol was designed to compare implant survival rates, changes in crestal bone for titanium MS fixtures placed in one and two stages, and plasma-sprayed solid-screw fixtures placed in one surgical stage. Twenty-nine patients ranging in age from 24 to 82 years received MS fixtures in one stage. The average age for males was 58 years (n = 11), whereas the ages for females (n = 18) ranged from 15 to 84 years (average 58 years). Twenty-nine patients received machined titanium fixtures placed in two stages. There were 20 females ranging in age from 23 to 74 years (average 54 years) and 9 females ranging from 24 to 74 years (average 46 years). Twenty-five patients received TPS fixtures. There were 15 males, ranging in age from 57 to 79 (average 70), and 10 females, ranging in age from 40 to 83 years (average 62 years). Bone quality and quantity were determined from radiographs and during site preparation. Patient age, sex, location of implant placement according to jaw, length of fixtures, and number of lost fixtures were entered onto computer code sheets and continuously entered into a locked computer system. For one- and two-stage MS fixtures, nonstandardized periapical radiographs were taken at abutment connection and follow-up. Solid screws were x-rayed at prostheses connection and follow-up. The average time between implant restoration and radiographic follow-up was 15 months. The x-rays were scanned into a computer, and a program designed to measure radiographs was used to determine changes in crestal bone. Measurements for one- and two-stage MS fixtures were made from the top of the implant shoulder to the first bone to implant contact mesial and distally. Plasma-sprayed screws were measured from the bottom of the implant to the coronal most bone to implant contacts mesial and distally. Mesial-distal radiographic measurements were averaged and changes were compared using the t-test for related samples.
This report presents data from the 2- to 3-year follow-up examinations. Twenty-nine patients received 80 one-stage MS fixtures. Between 0 and 1 year, two fixtures were lost, resulting in a 97.5% cumulative survival rate (CSR). The CSR remained unchanged through the 2- to 3-year follow-up. Twenty-eight patients received 78 two-stage MS fixtures. One implant was lost prior to loading and two were lost between 0- and 1-year follow-up, yielding a 96.2% CSR at the end of 1 year. The CSR remained unchanged through the 2- to 3-year follow-up. Twenty-three patients received 78 solid-screw plasma-sprayed screws. One implant was lost prior to loading and one between the 0- to 1-year follow-up, accounting for a 97.4% CSR at the 2- to 3-year follow-up. Changes in bone crest measurements for one-stage titanium threaded fixtures were insignificant (-0.11 mm, p = .08, maxillary; 0.07 mm, p = .42, mandibular). For two-stage MS fixtures, crestal bone loss was insignificant in maxillae (-0.16 mm, p = .92) and significant in mandibles (-0.43 mm, p = .000). There was significant bone loss for TPS implants in maxillae and mandibles (maxillae, 1.31 mm, p = .04; mandibles, 0.98 mm, p = .000).
Cumulative survival rates for MS fixtures placed in one and two stages as well as one-stage TPS screws up to the 2- to 3-year follow-up examination were similar, indicating excellent clinical results. Radiographic measurements for changes in crestal bone loss were clinically insignificant for fixtures placed in one stage. For two-stage fixtures, maxillary changes were insignificant, whereas mandibular bone loss was statistically significant but clinically insignificant. Changes in crestal bone loss for TPS implants were statistically significant.
布伦马克种植体最初分两个阶段植入，而钛等离子喷涂（TPS）实心螺钉则一次性植入。两种类型种植体的长期存活率都很高。据报道，一次性植入的机械加工螺纹状（MS）钛种植体的存活率也很高。少数研究比较了不同的种植体系统和种植体植入方法。
本研究的目的是报告一项前瞻性纵向多中心研究的临床结果，该研究比较了一次性或分两阶段植入的布伦马克MS种植体（美国加利福尼亚州约巴林达市诺贝尔生物保健公司）与一次性TPS系统（瑞士瓦尔登堡市ITI士卓曼公司）。
设计了一项方案，以比较种植体存活率、一次性和分两阶段植入的钛MS种植体以及在一个手术阶段植入的等离子喷涂实心螺钉种植体的牙槽嵴骨变化。29例年龄在24至82岁之间的患者一次性接受了MS种植体。男性的平均年龄为58岁（n = 11），而女性（n = 18）的年龄在15至84岁之间（平均58岁）。29例患者分两阶段接受了机械加工钛种植体。有20名年龄在23至74岁之间（平均54岁）的女性和9名年龄在24至74岁之间（平均46岁）的女性。25例患者接受了TPS种植体。有15名男性，年龄在57至79岁之间（平均70岁），10名女性，年龄在40至83岁之间（平均62岁）。根据X光片和种植位点准备情况确定骨质量和骨量。将患者的年龄、性别、根据颌骨确定的种植体植入位置、种植体长度以及丢失种植体的数量录入计算机编码表，并持续录入一个锁定的计算机系统。对于一次性和分两阶段植入的MS种植体，在基台连接和随访时拍摄非标准化根尖片。实心螺钉在修复体连接和随访时进行X光检查。种植体修复与X光随访之间的平均时间为15个月。将X光片扫描到计算机中，并使用一个设计用于测量X光片的程序来确定牙槽嵴骨的变化。对于一次性和分两阶段植入的MS种植体，测量从种植体肩部顶部到种植体近中和远中第一个骨接触点的距离。对于等离子喷涂螺钉，从种植体底部到种植体近中和远中最冠方的骨接触点进行测量。对近中-远中X光测量值进行平均，并使用相关样本的t检验比较变化情况。
本报告展示了2至3年随访检查的数据。29例患者接受了80枚一次性MS种植体。在0至1年之间，有2枚种植体丢失，累积存活率（CSR）为97.5%。在2至3年的随访期间，CSR保持不变。28例患者接受了78枚分两阶段植入的MS种植体。1枚种植体在加载前丢失，2枚在0至1年随访期间丢失，1年后的CSR为96.2%。在2至3年的随访期间，CSR保持不变。23例患者接受了78枚实心螺钉等离子喷涂螺钉。1枚种植体在加载前丢失，1枚在0至1年随访期间丢失，在2至3年随访时的CSR为97.4%。一次性钛螺纹种植体的牙槽嵴骨测量变化不显著（上颌为-0.11 mm，p = 0.08；下颌为0.07 mm，p = 0.42）。对于分两阶段植入的MS种植体，上颌的牙槽嵴骨丢失不显著（-0.16 mm，p = 0.92），而下颌显著（-0.43 mm，p = 0.000）。TPS种植体在上颌和下颌均有显著的骨丢失（上颌为1.31 mm，p = 0.04；下颌为0.98 mm，p = 0.000）。
在2至3年的随访检查中，一次性和分两阶段植入的MS种植体以及一次性TPS螺钉的累积存活率相似，表明临床效果良好。对于一次性植入的种植体，牙槽嵴骨丢失变化的X光测量在临床上不显著。对于分两阶段植入的种植体，上颌的变化不显著，而下颌骨丢失在统计学上显著但临床上不显著。TPS种植体的牙槽嵴骨丢失变化在统计学上显著。
