ABSTRACT
@#Tooth loss is accompanied by alveolar bone absorption or defect, resulting in insufficient bone and soft tissue. In addition to restoring the masticatory function of missing teeth, implant treatment should also needs to restore the contour and shape of the dental arch. Guided bone regeneration is a common means of bone increase. Xenogeneic granular bone substitute materials are widely used in the field of clinical bone augmentation due to their advantages of long degradation time and low immunogenicity, but other problems, such as inconvenient operation and low osteogenic activity, remain. Plasmatrix can effectively improve the effect of oral tissue regeneration and reduce the occurrence of postoperative complications, and its application in oral tissue regeneration is gradually increasing. This article first introduces the main application forms of plasmatrix in horizontal bone augmentation (mainly solid plasmatrix membrane and plasmatrix bone block), and reclassifies horizontal bone defects according to commonly used decision-making schemes in clinical bone augmentation, in other words, whether the implant can be placed in the ideal position and whether there is bone dehiscence after implantation. Type Ⅰ defects refers to the situation where the bone at the implant site can allow the insertion of an implant with ideal size, and there is no bone dehiscence around the implant, but the alveolar bone contour is not ideal; type Ⅱ defects refers to the situation that when an ideal size implant is placed at the implant site determined by the future prosthesis position, there will be bones on three sides of the implant, but there is bone dehiscence in the buccal bone wall (the length of bone dehiscence is less than 50% of the implant length); type Ⅲ defects refers to the situation where the bone volume at the implant site is not enough to for the placement of the ideal size implant at the ideal position, and bone grafting is required to restore the bone volume before the implant placement. The application of plasmatrix in different types of bone defects is then described. In type Ⅰ bone defects, the solid plasmatrix membrane is used instead of the collagen membrane; in type Ⅱ bone defects, the bone defect around the implant is filled by plasmatrix bone block and then covered with collagen membrane and solid plasmatrix membrane; and in type Ⅲ bone defects, plasmatrix bone block is used to replace autogenous bone block to fill the defect area, and titanium screws are used for fixation. The defect is then covered with a collagen membrane and a solid plasmatrix membrane. This article aims to provide oral clinicians with a comprehensive understanding of plasmatrix and simplify the guidelines for bone regeneration operations.
ABSTRACT
Objective To evaluate the therapeutic outcome of horizontal bone augmentation by using the modified split crest technique of piezosurgery in mandible molar area. Methods The present study reviewed the record of 15 patients from 2016 January to 2017 March in the department of oral implantology center of Stomato-logical Hospital of Southern Medical University,who underwent the modified split crest technique of piezosurgery in mandible molar area. Preoperative CBCT was performed to determine the bone thickness of the toothless alveo-lar crest of the mandibular posterior region,and the bone thickness was less than 3 mm. The modified split crest technique of piezosurgery was performed for the horizontal bone augmentation at mandibular posterior region. Meanwhile,GBR and the postoperative CBCT were performed to determine the bone width increments,followed with 1-week anti-inflammatory therapy postoperation. Three months after the operations,the bone width incre-ment was examined by CBCT. SPSS13.0 software was used to analyze the collected data. Results The modified split crest technique of piezosurgery in mandible molar area was successfully established,resulting in the mini-mal operative wounds and the slight postoperative reaction,without obvious infection. The postoperative crest width increase achieved 6.05 ± 0.65 mm. At 3 months after operation,the crest width increase reduced to(5.81 ± 0.61)mm. There were significant differences of the alveolar ridge thickness between the preoperative and post-operative patients(P<0.05). There were significant differences between the preoperative crest width and the 3 months after treatment(P<0.05). Conclusion Horizontal bone augmentation of the modified split crest tech-nique of piezosurgery was efficient,which could be performed in very narrow alveolar ridge,and which was rela-tively safe and accurate,with less trauma. No damage was observed to the soft tissue,and the cutting direction can be well controlled.
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