Periodontal repair in dogs: rhBMP-2 significantly enhances bone formation under provisions for guided tissue regeneration

BACKGROUND: Recombinant human bone morphogenetic protein-2 (rhBMP-2) has been shown to support the regeneration of alveolar bone and periodontal attachment in surgically created periodontal defects and in defects with a history of dental plaque and calculus exposure. Periodontal regeneration has also been shown following guided tissue regeneration using space-providing expanded polytetrafluoroethylene (ePTFE) devices. The objective of this study was to evaluate the influence of rhBMP-2 on regeneration of alveolar bone and periodontal attachment used in conjunction with a space-providing ePTFE device. METHODS: Routine, critical-size, 5-6 mm, supra-alveolar, periodontal defects were created around the third and fourth mandibular premolar teeth in four young adult Hound Labrador mongrel dogs. rhBMP-2 (0.2 mg/ml) in an absorbable collagen sponge (rhBMP-2/ACS) or buffer/ACS (control) implants were randomly assigned to be placed around the premolar teeth in the left and right jaw quadrants in subsequent animals. Space-providing ePTFE devices with 300-microm laser-drilled pores, 0.8 mm apart, were used to cover the rhBMP-2 and control implants. The gingival flaps were advanced for primary wound closure. The animals were euthanized at 8 weeks postsurgery for histologic and histometric analyses. RESULTS: Bone regeneration and ankylosis were significantly increased in jaw quadrants receiving rhBMP-2/ACS compared to control (bone height 4.8+/-0.3 versus 2.0+/-0.2 mm, p=0.001; bone area 10.9+/-1.3 versus 1.4+/-0.1 mm2; p=0.009, and ankylosis 2.2+/-0.2 versus 0.04+/-0.7 mm; p=0.01). No differences between groups were found for cementum regeneration and root resorption. CONCLUSIONS: rhBMP-2 significantly enhances regeneration of alveolar bone in conjunction with a space-providing, macroporous ePTFE device for GTR.     

Bone reconstruction following implantation of rhBMP-2 and guided bone regeneration in canine alveolar ridge defects

BACKGROUND: Alveolar ridge aberrations commonly require bone augmentation procedures for optimal placement of endosseous dental implants. The objective of this study was to evaluate local bone formation following implantation of recombinant human bone morphogenetic protein-2 (rhBMP-2) in an absorbable collagen sponge (ACS) carrier with or without provisions for guided bone regeneration (GBR) as potential treatment modalities for alveolar augmentation. METHODS: Surgically induced, large, mandibular alveolar ridge saddle-type defects (2 defects/jaw quadrant) in seven young adult Hound dogs were assigned to receive rhBMP-2/ACS, rhBMP-2/ACS combined with GBR (rhBMP-2/GBR), GBR, and surgery controls. The animals were euthanized at 12 weeks post-surgery when block sections of the defect sites were collected for histologic analysis. RESULTS: Clinical complications included swelling for sites receiving rhBMP-2 and wound failure with exposure of the barrier device for sites receiving GBR (4/6) or rhBMP-2/GBR (3/7). The radiographic evaluation showed substantial bone fill for sites receiving rhBMP-2/ACS, rhBMP-2/GBR, and GBR. In particular, sites receiving rhBMP-2/GBR presented with seroma-like radiolucencies. The surgery control exhibited moderate bone fill. To evaluate the biologic potential of the specific protocols, sites exhibiting wound failure were excluded from the histometric analysis. Sites receiving rhBMP-2/ACS or rhBMP-2/GBR exhibited bone fill averaging 101%. Bone fill averaged 92% and 60%, respectively, for sites receiving GBR and surgery controls. Bone density ranged from 50% to 57% for sites receiving rhBMP-2/ACS, GBR, or surgery controls. Bone density for sites receiving rhBMP-2/GBR averaged 34% largely due to seroma formation encompassing 13% to 97% of the sites. CONCLUSION: rhBMP-2/ACS appears to be an effective alternative to GBR in the reconstruction of advanced alveolar ridge defects. Combining rhBMP-2/ACS with GBR appears to be of limited value due to the potential for wound failure or persistent seromas.     

Effect of rhBMP-2 on guided bone regeneration in humans

Abstract: The aim of the present clinical study was to test whether or not the addition of recombinant human bone morphogenetic protein‐2 (rhBMP‐2) to a xenogenic bone substitute mineral (Bio‐Oss^®) will improve guided bone regeneration therapy regarding bone volume, density and maturation. In 11 partially edentulous patients, 34 Brånemark implants were placed at two different sites in the same jaw (five maxillae, six mandibles) requiring lateral ridge augmentation. The bone defects were randomly assigned to test and control treatments: the test and the control defects were both augmented with the xenogenic bone substitute and a resorbable collagen membrane (Bio‐Gide^®). At the test sites, the xenogenic bone substitute mineral was coated with rhBMP‐2 in a lyophilization process. Following implant insertion (baseline), the peri‐implant bone defect height was measured from the implant shoulder to the first implant–bone contact. After an average healing period of 6 months (SD 0.17, range 5.7–6.2), the residual defects were again measured and trephine burs were used to take 22 bone biopsies from the augmented regions. The healing period was uneventful except for one implant site that showed a wound dehiscence, which spontaneously closed after 4 weeks. Later at reentry, all implants were stable. At baseline, the mean defect height was 7.0 mm (SD 2.67, range 3–12 mm) at test and 5.8 mm (SD 1.81, range 3–8 mm) at control sites. At reentry, the mean defect height decreased to 0.2 mm (SD 0.35, range 0–1 mm) at test sites (corresponding to 96% vertical defect fill) and to 0.4 mm (SD 0.66, range 0–2 mm) at the control site (vertical defect fill of 91%). Reduction in defect height from baseline to reentry for both test and control sites was statistically significant (Wilcoxon P<0.01). Histomorphometric analysis showed an average area density of 37% (SD 11.2, range 23–51%) newly formed bone at test sites and 30% (SD 8.9, range 18–43%) at control sites. The fraction of mineralized bone identified as mature lamellar bone amounted to 76% (SD 14.4, range 47.8–94%) at test compared to 56% (SD 18.3, range 31.6–91.4%) at control sites (paired t‐test P<0.05). At BMP‐treated sites 57% (SD 16.2, range 29–81%) and at control sites 30% (SD 22.6, range 0–66%) of the surface of the bone substitute particles were in direct contact with newly formed bone (paired t‐test P<0.05). It is concluded that the combination of the xenogenic bone substitute mineral with rhBMP‐2 can enhance the maturation process of bone regeneration and can increase the graft to bone contact in humans. rhBMP‐2 has the potential to predictably improve and accelerate guided bone regeneration therapy.     

Periodontal repair in dogs: space-providing ePTFE devices increase rhBMP-2/ACS-induced bone formation

BACKGROUND: Recombinant human bone morphogenetic protein-2 (rhBMP-2) technologies have been shown to enhance alveolar bone formation significantly. Biomaterial (carrier) limitations, however, have restricted their biologic potential for indications where compressive forces may limit the volume of bone formed. The objective of this proof-of-principle study was to evaluate the potential of a space-providing, macroporous ePTFE device to define rhBMP-2-induced alveolar bone formation using a discriminating onlay defect model. METHODS: Routine, critical size, 5-6 mm, supra-alveolar, periodontal defects were created around the third and fourth mandibular premolar teeth in four young adult Hound Labrador mongrel dogs. All jaw quadrants received rhBMP-2 (0.4 mg) in an absorbable collagen sponge (ACS) carrier. Contralateral jaw quadrants in subsequent animals were randomly assigned to receive additionally the dome-shaped, macroporous ePTFE device over the rhBMP-2/ACS implant or no additional treatment. The gingival flaps were advanced to cover the ePTFE device and teeth, and sutured. Animals were scheduled for euthanasia to provide for histologic observations of healing at 8 weeks postsurgery. RESULTS: Healing was uneventful without device exposures. New bone formation averaged (+/-SD) 4.7+/-0.2 mm (98%) and 4.5+/-0.4 mm (94%) of the defect height, respectively, for jaw quadrants receiving rhBMP-2/ACS with the ePTFE device or rhBMP-2/ACS alone (p>0.05). In contrast, the regenerated bone area was significantly enhanced in jaw quadrants receiving rhBMP-2/ACS with the ePTFE device compared to rhBMP-2/ACS alone (9.3+/-2.7 versus 5.1+/-1.1 mm2; p<0.05). Cementum formation was similar for both treatment groups. Ankylosis compromised periodontal regeneration in all sites. CONCLUSIONS: The results suggest that the novel space-providing, macroporous ePTFE device appears suitable as a template to define rhBMP-2/ACS-induced alveolar bone formation.     

Space-providing expanded polytetrafluoroethylene devices define alveolar augmentation at dental implants induced by recombinant human bone morphogenetic protein 2 in an absorbable collagen sponge carrier

Background: Surgical implantation of recombinant human bone morphogenetic protein 2 (rhBMP‐2) in an absorbable collagen sponge carrier (ACS) significantly enhances bone regeneration in horizontal alveolar defects; however, sufficient quantities of bone for implant dentistry are not routinely obtained. Purpose: The objective of this proof‐of‐principle study was to evaluate the potential of a space‐providing macroporous expanded polytetrafluoroethylene (ePTFE) device to control volume and geometry of rhBMP‐2/ACS‐induced alveolar bone augmentation. Materials and Methods: Bilateral critical‐size supra‐alveolar periimplant defects were created in four Hound‐Labrador mongrel dogs. Two turned and one surface‐etched 10 mm titanium dental implants were placed 5 mm into the surgically reduced alveolar ridge creating 5 mm supra‐alveolar defects. rhBMP‐2/ACS (0.4 mg rhBMP‐2) was placed around the exposed dental implants. Additionally, one jaw quadrant in each animal was randomly assigned to receive the domeshaped macroporous ePTFE device. Mucoperiosteal flaps were advanced for primary wound closure. The animals were euthanized at 8 weeks post surgery for histometric analysis. Results: The space‐providing macroporous ePTFE device defined the volume and geometry of rhBMP‐2/ACS‐induced bone formation, whereas bone formation at sites receiving rhBMP‐2/ACS alone varied considerably. Vertical bone gain at turned dental implants averaged (SD) 4.7 ± 0.2 mm at sites receiving rhBMP‐2/ACS and the ePTFE device compared with 3.5 ± 0.9 mm at sites receiving rhBMP‐2/ACS only. The corresponding values for rhBMP‐2/ACS‐induced bone area were 9.6 ± 0.7 mm ² and 7.5 ± 6.2 mm ². There was a highly significant correlation between induced bone area and the space provided by the ePTFE device (p .001). There was no difference in induced bone density or bone‐implant contact between the two technologies. These observations were consistent with those observed at surface‐etched dental implants. Conclusions: The data from this study suggest that a space‐providing macroporous ePTFE device defines rhBMP‐2/ACS‐induced alveolar augmentation to provide adequate bone quantities for implant dentistry. The dental implant surface technology does not appear to substantially influence bone formation.     

Denaturation of demineralized bone matrix significantly reduces bone formation by guided tissue regeneration

AIM: To examine in a discriminating capsule model whether denaturation of demineralized bone matrix (DBM) by heating may influence bone formation. MATERIALS AND METHODS: DBM was produced from the long bones of rats. Half the portion of DBM was denatured by heating in distilled water for 20 min at temperatures between 70 degrees C and 90 degrees C. Prior to the study, the destruction of the osteoinductive properties of the DBM was confirmed in three rats following intramuscular implantation. Thirty, 4-month-old, male albino rats of the Wistar strain were used in the study. Following surgical exposure of the mandibular ramus, a hemispherical Teflon capsule (internal diameter = 5.0 mm) was placed, with its open part facing the lateral aspect of the ramus. On one side (test side), the capsule was loosely packed with denatured DBM, while on the contralateral side, serving as control, the capsule was loosely packed with the same amount of non-denatured DBM. After healing periods of 30, 60, and 120 days, groups of 10 animals were killed and 40-70 microm thick undecalcified sections of the capsules were produced. Three sections from each specimen, representing the mid-portion of the capsule, were subjected to histological analysis and computer-assisted planimetric measurements. RESULTS: Increasing amounts of newly formed bone were observed in both test and control capsules during the experimental period. At 4 months, the new bone formed in the control capsules occupied 46.7% of the cross-sectional area of the capsules, while it was only 19.1% in the test capsules (P<0.05). CONCLUSION: Denaturation of DBM by heating significantly reduces bone formation by guided tissue regeneration.     

Regeneration and enlargement of jaw bone using guided tissue regeneration

The purpose of this study was to present the surgical procedures and the clinical results of guided tissue regeneration (GTR) treatment aimed at regenerating local jaw bone in situations where the anatomy of the ridge did not allow the placement of dental implants. 12 patients were selected for ridge enlargement or bony defect regeneration. A combined split- and full-thickness flap was raised in areas designated for subsequent implant placement. Following perforation of the cortical bone to create a bleeding bone surface, a PTFE membrane was adjusted to the surgical site in such a way that a secluded space was created between the membrane and the subjacent bone surface in order to increase the width of the ridge or to regenerate bony defects present. Complete tension-free closure of the soft tissue flap was emphasized. Following a healing period of 6 to 10 months, reopening procedures were performed and the gain of bone dimension was assessed. In 9 patients with 12 potential implant sites, a sufficient bone volume was obtained to allow subsequent implant placement. The gain of new bone formation varied between 1.5 and 5.5 mm. In 3 patients, acute infections developed which necessitated early removal of the membranes and no bone regeneration could be achieved. The results of the study indicate that the biological principle of GTR is highly predictable for ridge enlargement or defect regeneration under the prerequisite of a complication-free healing.     

Periodontal repair in dogs: guided tissue regeneration enhances bone formation in sites implanted with a coral-derived calcium carbonate biomaterial

BACKGROUND: Previous studies suggest that a bioresorbable calcium carbonate coral implant (CI) supports space provision and bone formation for guided tissue regeneration (GTR). However, it could not be discerned whether observed effects were because of GTR or whether the CI possessed osteoconductive properties enhancing bone formation. The objective of this study was to evaluate bone formation associated with the CI biomaterial in the presence and absence of provisions for GTR. METHODS: Routine, critical size, 6 mm, supra-alveolar periodontal defects were created in 12 young adult Beagle dogs. Five animals received the CI alone (Biocoral 1000). Seven animals received the CI/GTR combination using an expanded polytetrafluoroethylene barrier (GORE-TEX Regenerative Material). The animals were euthanized at 4 weeks postsurgery and tissue blocks of the experimental sites were collected and processed for histometric analysis. RESULTS: Clinical healing was uneventful. The histopathologic and histometric analysis revealed significantly increased bone formation (height and area) in sites receiving the CI/GTR combination compared with CI alone (2.3+/-0.6 versus 1.2+/-0.9 mm; and 3.1+/-0.8 versus 1.2+/-1.1 mm2; p<0.05). The CI biomaterial appeared to be mostly unassociated with new bone formation; the CI particles were observed sequestered in newly formed bone, fibrovascular marrow, and in the supra-alveolar connective tissue. Cementum formation was limited and observed in few sites for both treatment protocols. CONCLUSION: While GTR promoted new bone formation, the CI contributed limited, if any, osteoconductive effects.     

Prognostic factors for alveolar regeneration: effect of tissue occlusion on alveolar bone regeneration with guided tissue regeneration

OBJECTIVES: Design criteria for guided tissue regeneration (GTR) devices include biocompatibility, cell occlusion, space-provision, tissue integration, and ease of use. The objective of this study was to evaluate the effect of cell occlusion and space-provision on alveolar bone regeneration in conjunction with GTR. METHODS: Routine, critical-size, 6 mm, supra-alveolar, periodontal defects were created in 6 young adult Beagle dogs. Space-providing ePTFE devices, with or without 300-microm laser-drilled pores were implanted to provide for GTR. Treatments were alternated between left and right jaw quadrants in subsequent animals. The gingival flaps were advanced for primary intention healing. The animals were euthanized at week 8 post surgery. The histometric analysis assessed regeneration of alveolar bone relative to space-provision by the ePTFE device. RESULTS: A significant relationship was observed between bone regeneration and space-provision for defect sites receiving the occlusive (beta = 0.194; p < 0.02) and porous (beta = 0.229; p < 0.0004) GTR devices irrespective of treatment (p = 0.14). The bivariate analysis showed that both space-provision and device occlusivity significantly enhanced bone regeneration. Hence, sites receiving the occlusive GTR device and sites with enhanced space-provision showed significantly greater bone regeneration compared to sites receiving the porous GTR device (p = 0.03) or more limited space-provision (p = 0.0002). CONCLUSIONS: Cell occlusion and space-provision may significantly influence the magnitude of alveolar bone regeneration in conjunction with guided tissue regeneration.     

冷冻异体骨膜引导即刻种植体周围骨缺损修复的临床研究

目的：观察机体对冷冻异体骨膜的反应及其引导骨组织再生的效果，方法：在实验研究成功的基础上，将冷冻异体骨膜作为引导组织再生膜性材料应用于引导即刻种植义齿植体周围骨缺损的修复。结果：临床观察证实机体对冷冻异体骨膜无排斥反应，膜无脱出，无感染，骨缺损修复率达到92．12％，结论：冷冻异体骨膜是一种理想的引导组织再生膜性材料。     

A volumetric study of guided bone regeneration around titanium implants in the New Zealand white rabbit

Previous studies have shown the ability for bone to grow under occlusive membranes. This study was undertaken to determine the time required for bone to form in the space created under the membrane and to determine the amount of bone that may be grown under the membrane. Thirty-two New Zealand white rabbits were divided into three groups. A Brånemark implant, having a diameter of 3.75 mm with a length of 7 mm, was placed in each tibia and Gore-Tex membrane was draped over the implant on the experimental side and tethered to the wound margin. Sixteen rabbits were sacrificed at six weeks, eight at twelve weeks, and eight at eighteen weeks. At six weeks the available space under the membrane was filled to 68 per cent, at twelve weeks it was 45 per cent, and at eighteen weeks 54 per cent. A comparison of bone height measurements on test and control sides showed a significant difference (p=0.0001) at the three time intervals. A comparison of grown bone volumes (test vs control) was also statistically significant (p=0.0001). The ability to grow bone under an occlusive membrane was confirmed but the long-term survival rate and ability to support load needs to be investigated.     

引导骨再生屏障膜改良的研究进展

引导骨再生术是解决骨组织缺损问题的重要技术,引导骨再生屏障膜在其中发挥着不可替代的作用。引导骨再生膜是防止成纤维细胞进入骨缺损部位的屏障,同时可促进成骨细胞的黏附、增殖和骨组织再生。由于目前广泛应用于引导骨再生的胶原膜尚存在一些缺陷,探索具有更优良性质的引导骨再生屏障膜成为一个重要的课题。因此出现了从抗菌性的改良、成骨性的改良和新材料的研发等多方面的努力以改良引导骨再生膜。本文回顾了近年来引导骨再生膜改进的研究成果和进展,展望了未来相关研究的发展方向,为进一步展开骨再生及修复的相关研究工作提供参考。     

引导骨再生屏障膜改良的研究进展

引导骨再生术是解决骨组织缺损问题的重要技术,引导骨再生屏障膜在其中发挥着不可替代的作用。引导骨再生膜是防止成纤维细胞进入骨缺损部位的屏障,同时可促进成骨细胞的黏附、增殖和骨组织再生。由于目前广泛应用于引导骨再生的胶原膜尚存在一些缺陷,探索具有更优良性质的引导骨再生屏障膜成为一个重要的课题。因此出现了从抗菌性的改良、成骨性的改良和新材料的研发等多方面的努力以改良引导骨再生膜。本文回顾了近年来引导骨再生膜改进的研究成果和进展,展望了未来相关研究的发展方向,为进一步展开骨再生及修复的相关研究工作提供参考。     

Bone regeneration using the principle of guided tissue regeneration

The biological principle of "guided tissue regeneration" (GTR) was developed for regenerating periodontal tissues, lost as a result of periodontal disease. This principle was based on the hypothesis that non-desirable types of tissue cells can be prevented from migrating into a wound by means of a membrane barrier and at the same time giving preference to those particular cells to repopulate the wound, which have the capacity to regenerate the desired type of tissue. This principle may have its application in many areas of surgery, aimed at regeneration of lost tissues. One such area is osseous surgery aimed at bone regeneration. In the present paper, a series of experiments in laboratory animals using the method of GTR for regeneration of various types of bone defects are presented as well as examples of application in humans for regeneration of jaw bone defects in conjunction with the placement of dental implants.     

GBR技术引导颌骨再生的研究进展

引导骨再生（GBR）是修复种植体周围缺损的重要方法,但在成骨效果上仍有不足。理论上组织工程将生长因子和生物活性材料应用于GBR可以提高疗效,但是目前临床上尚未建立起可预测疗效的种植体周围缺损再生疗法,甚至有研究发现在GBR中使用生长因子后还存在成骨长期稳定性不良的现象,这与理论上预计的结果不符。解决这一问题是推进生长因子应用的关键,通过查阅文献与分析,文中给出了两种可能的原因：生长因子后期水平过低和加速屏障膜降解作用,并据此提出验证的方法,为进一步研究提供参考和依据。     

改良骨劈开联合引导骨再生术修复上颌前牙区水平向严重骨缺损的临床效果

目的评价上颌前牙区水平向严重骨缺损应用改良骨劈开联合引导骨再生术（GBR）的临床效果。 方法选取2015年2月至2016年3月就诊于南方医科大学口腔医院种植中心,上颌前牙区水平向严重骨缺损的拟采取分阶段骨增量患者50例,符合上颌前牙区单牙缺失,4 mm≥水平向骨宽度≥2 mm,垂直向骨高度正常。按照简单随机抽样法分为观察组和对照组,各25例。观察组使用改良骨劈开联合GBR;对照组使用常规GBR。各组于骨增量后6个月植入种植体25枚,植入后4 ~ 6个月行上部结构修复,随访6个月行临床及影像学检查,以种植体存留率、红色美学指数（PES）、水平向骨宽度、边缘骨吸收量评估临床效果。使用SPSS 21.0软件进行数据分析。 结果两组随访率100%,愈合期及随访过程中均无种植体脱落,种植体存留率均为100%。观察组PES修复当日为6.96 ± 0.98,负重6个月为8.28 ± 1.28;对照组修复当日为7.12 ± 1.13,负重6个月为8.12 ± 1.30。观察组和对照组修复当日及负重6个月PES差异均无统计学意义（t₀ = -0.535,P₀ = 0.595;t₆ = 0.439,P₆ = 0.663）。观察组术后6个月水平向骨宽度为（7.08 ± 0.40）mm,对照组为（5.81 ± 0.53）mm,差异具有统计学意义（t = -9.461,P<0.001）。观察组负重6个月的近中边缘骨吸收量为（0.34 ± 0.02）mm,对照组为（0.45 ± 0.04）mm,差异具有统计学意义（t = -12.86,P<0.001）。观察组负重6个月的远中边缘骨吸收量为（0.35 ± 0.02）mm,对照组为（0.44 ± 0.04）mm,差异有统计学意义（t = -10.44,P<0.001）。 结论应用改良骨劈开联合GBR有效解决上颌前牙区水平向严重骨缺损并取得良好的临床效果。     

GBR技术应用于上前牙种植骨缺损的临床研究

目的：评估引导骨再生技术（GBR）在上前牙不同类型骨缺损种植修复中的效果。方法：对35例上前牙牙槽骨缺损种植的患者采用GBR技术进行骨增量,其中29例种植体周围骨缺损患者仅采用GBR技术,在植体植入骨床后,同期植入Bio～oss人工骨粉,表面盖Bio～gide可吸收性胶原膜;6例牙槽骨缺损患者采用移植自体块状骨联合Bio～oss人工骨粉,盖Bio～gide可吸收性胶原膜,5～6个月后行Ⅱ期种植体植入术。结果：所有患者在植体植入术后6～12个月临床观察种植体与骨结合良好,软组织形态与周围组织一致,行冠或桥修复,修复后12个月随诊复查无种植体失败。结论：引导骨再生技术皆能有效地对上前牙不同类型骨缺损进行骨增量,符合美学种植要求。     

双抗胶原膜应用于引导组织再生的长期疗效观察

目的 观察双抗胶原膜应用于引导组织再生(guided tissue regeneration,GTR)的长期疗效,以期为临床提供参考.方法 对24例重度牙周炎患者的26颗患牙按单双数法随机分组,分别应用双抗胶原膜(试验组)和牛腱胶原膜(对照组)对3l处垂直型骨吸收和根分叉病变进行GTB治疗,试验组共13例患者,14颗患牙,16处骨缺损;对照组共11例患者,12颗患牙,15处骨缺损.分别于术前、术后6个月、1、3和6年进行临床附着水平、计算机辅助密度影像分析(computer assisted densitometry image analysis,CADIA)等指标的临床检查,并对结果进行统计学分析.结果 GTR术后1年,试验组临床附着获得是(3.93±1.74)mm,对照组是(2.25±1.90)mm(t=2.146,P=0.044),CADIA值分别增加(53.14±21.35)和(32.96±17.97)(t=2.319,P=0.031).GTR术后6年与术后1年临床附着水平相比,试验组和对照组仅分别平均有0.35 mm和0.34 mm的附着丧失.结论 在6年随访的病例中,双抗胶原膜应用于引导组织再生所获得的再生牙周组织可以长期保持稳定.     

Comparable efficacy of silk fibroin with the collagen membranes for guided bone regeneration in rat calvarial defects

PURPOSE

Silk fibroin (SF) is a new degradable barrier membrane for guided bone regeneration (GBR) that can reduce the risk of pathogen transmission and the high costs associated with the use of collagen membranes. This study compared the efficacy of SF membranes on GBR with collagen membranes (Bio-Gide®) using a rat calvarial defect model.

MATERIALS AND METHODS

Thirty-six male Sprague Dawley rats with two 5 mm-sized circular defects in the calvarial bone were prepared (n=72). The study groups were divided into a control group (no membrane) and two experimental groups (SF membrane and Bio-Gide®). Each group of 24 samples was subdivided at 2, 4, and 8 weeks after implantation. New bone formation was evaluated using microcomputerized tomography and histological examination.

RESULTS

Bone regeneration was observed in the SF and Bio-Gide®-treated groups to a greater extent than in the control group (mean volume of new bone was 5.49 ± 1.48 mm³ at 8 weeks). There were different patterns of bone regeneration between the SF membrane and the Bio-Gide® samples. However, the absolute volume of new bone in the SF membrane-treated group was not significantly different from that in the collagen membrane-treated group at 8 weeks (8.75 ± 0.80 vs. 8.47 ± 0.75 mm³, respectively, P=.592).

CONCLUSION

SF membranes successfully enhanced comparable volumes of bone regeneration in calvarial bone defects compared with collagen membranes. Considering the lower cost and lesser risk of infectious transmission from animal tissue, SF membranes are a viable alternative to collagen membranes for GBR.