A Prospective Randomized-controlled Multicenter Clinical and Histological Study of Extraction Site Augmentation With mp3 vs. Apatos
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 30
- 主要终点
- Volume of the alveolar ridge
研究概览
简要总结
The primary aim of the present multicenter randomized controlled trial was to evaluate and compare the shortterm clinical and histological changes of extraction sockets after ridge preservation procedures with changes of extraction sockets that healed naturally.
The secondary aim was to evaluate which, if any extraction socket characteristics could have affected tissue changes occurring at the augmented as well as naturally healed sites.
Recruitment and enrollment of patients were performed from June 2011 to June 2012 in five university centers/private practice:
- University of Pisa;
- University of Murcia;
- University of Ancona;
- Private practice, Dr. Di Felice;
- University of Verona.
Randomization:
- extraction sockets with spontaneous healing;
- extraction sockets grafted with pre-hydrated collagenated cortico-cancellous porcine bone, with a particle size between 600 and 1000 μm;
- extraction sockets grafted with cortical porcine bone, with a particle size between 600 and 1000 μm.
Outcome Variables
- Complications
- Changes of ridge volume contour;
- Vertical bone changes;
- Buccal-Lingual Width;
- Histomorphometric parameters.
Sample size was calculated comparing outcome data between grafted sockets versus non-grafted sockets. The primary parameter was the change in mid-buccal vertical height (0.7±1.4mm and 3.6±1.5mm, respectively, for the test and control groups) (Barone et al. 2008). Final sample size was increased to 30 subjects per group due to possible patient dropout events. Each center contributed according to the predetermined 1:1:1 ratio; the fresh extraction socket was considered the unit of randomization.
Corrections for balancing the three experimental groups for confounding factors were not applied.
A matrix elaborator performed all the analyses§§: multi-way analysis of variance (ANOVAn) was applied, then appropriate post hoc comparison tests were run; post hoc estimated effect sizes were calculated with a power of 0.9. The level of statistical significance was set at 0.05 for all analyses.
详细描述
BACKGROUND
Following tooth extraction, the alveolar ridge undergoes a marked change. During the first year after tooth extraction, about 50% of the bucco-lingual ridge dimension will be lost. Furthermore, ridge reduction will become more pronounced from a buccal than from a lingual/palatal aspect. The hard tissue modelling and remodelling following tooth extraction were studied in the dog model. It was demonstrated that the socket was first occupied by a coagulum that was replaced with granulation tissue, provisional connective tissue and woven bone. This immature hard tissue was subsequently replaced with lamellar bone and bone marrow. During the healing phase, the height of the buccal bone wall was substantially reduced. In addition, about 30% of the marginal portion of the alveolar process of the extraction site was lost.
Several approaches have been tested to preserve or improve the dimension and contour of the ridge following tooth extraction including the use of various graft or filler materials such as autografts, allografts, xenografts and/ or barrier membranes. The most recent studies on animals as well as in humans showed that the placement of xenografts in fresh extraction sockets promoted de novo hard tissue formation, in particular in the marginal portion of the extraction site. Moreover, it should be considered that the dimension of hard tissue walls was maintained and the profile of the ridge preserved. The data concerning socket preservation techniques in humans are still scarce. Therefore, firm conclusions about dimensional changes cannot be drawn currently; in reality, socket preservation procedures may aid in reducing the bone dimensional changes following tooth extraction. However, they do not completely prevent bone resorption so that a loss in width and height may be still expected; even if this procedure can allows a better location for implant placement and minimize the need for GBR procedure simultaneously with implant placement when compared to natural healed sites.
The histologic and histomorphometric evaluations showed the early phase of hard tissue formation were altered in extraction sockets that were grafted with a deproteinized bovine bone mineral immediately after tooth removal. The authors suggested that this modified wound healing and bone modelling may have been influenced by the presence of multinucleated cells that occurred in tissues harbouring the xenogenic graft. Thus, in grafted sites, substantial amount of newly formed bone could only be detected in the apical portion of the sockets where the graft material was absent. In the remaining portions of the grafted sockets a mildly inflamed provisional matrix surrounded the majority of bovine bone mineral particles, whose surface was frequently, but not always, coated with multinucleated cells. The biological behaviour can be explained with the type of biomaterial which is not resorbable/or slowly resorbable.
Given these premises, this prospective, randomized-controlled multicenter clinical study will compare the dimensional healing pattern, the quality of de novo bone formation and the implant placement in large tooth extraction sites after grafting with two types of xenografts: MP3 vs. Apatos by Tecnoss- Osteobiol.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Treatment
- 盲法
- Single (Outcomes Assessor)
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •18 years old or older
- •requiring one single tooth extraction and subsequently an implant-supported restoration
- •able to sign an informed consent form
排除标准
- •history of systemic diseases that would contraindicate oral surgical treatment;
- •long-term non-steroidal anti-inflammatory drug therapy;
- •lack of opposite occluding dentition in the area intended for extraction and subsequent implant placement;
- •Oral biphosphonate therapy;
- •absence of adjacent teeth;
- •unwillingness to return for the follow-up examination;
- •use of more than 10 cigarettes per day. Subjects smoking less than 10 cigarettes per day were requested to stop smoking before and after surgery; however, their compliance could not be monitored.
结局指标
主要结局
Volume of the alveolar ridge
时间窗: 36 months after grafting
Several impressions of the experimental sites were obtained from each patient. Impressions of the jaw were obtained in a one-step process with two viscosity polyvinyl siloxane impression materials. Within 24 h, model casts of the dental impressions were obtained using plaster of Paris. A scanner for cone-beam computerized tomography was employed for 3D file acquisition of the different model casts of each patient. The CBCT scan data were inserted into a Matrix Laboratory, and for each patient, positions of axial images related to all time frames were elaborated in space in such a way that the residual teeth were superimposable (Sbordone et al. 2012a,b); A volumetric evaluation (V in cm3) of the study models in the site subjected to alveolar ridge preservation was performed with Segment and Planning tool of SimPlant Pro 12.02.
Clinical vertical bone changes
时间窗: 36 months after grafting
Vertical bone changes were evaluated in mm with the use of a custom made stent at mesial, distal, buccal and lingual/palatal sites; it was set as the distance between the reference point and the most apical point of the marginal bone level. Changes at the vertical bone level were evaluated by subtracting the postoperative value from the respective baseline value.
Buccal-Lingual Width
时间窗: 36 months after grafting
Buccal-Lingual Width was evaluated in mm, measuring the distance between buccal and lingual/palatal plate with a periodontal probe. Changes at bucco-lingual width were calculated by subtracting the baseline value from the post-operative value.
Implant success
时间窗: 36 months after grafting
Implant failure (count) was defined as implant mobility, removal of implants caused by progressive bone loss or infection. The stability of each implant was evaluated at the delivery of prosthetic restoration and 1 year after implant insertion and two metallic handles of dental instruments were used to evaluate the stability of single crowns. Success rates (in percentage) were calculated according to the criteria suggested by Buser and colleagues.
Marginal bone loss
时间窗: 36 months after grafting
Bone loss was measured (in mm) by comparing the radiographs taken at baseline (immediately after placement) to the postoperative ones. The marginal bone height (MBL) was measured as the distance between the reference point (fixture-abutment interface) and the most apical point of the marginal bone level. Calibration was performed using the known thread-pitch distance of the implants (pitch = 1.0 mm), and fixture diameter and length.
次要结局
- Pink Esthetic Score(36 months after grafting)
- NMT: non-mineralized tissue(3 months after extraction procedure)
- Width of keratinized gingiva(36 months after grafting)
- RGP: residual graft particle(3 months after extraction procedure)
- Facial Soft Tissue Level(36 months after grafting)
- Papillae index(36 months after grafting)
- NFB: newly formed bone(3 months after extraction procedure)
研究者
Antonio Barone
Antonio Barone, DDS, PhD, MSc, University of Pisa Adjunct Professor
Tuscan Dental Institute