The Role of Two Different Collagen Membranes for Dehiscence Defect Around Implants in Humans
The aim of this study was to elucidate the role of 2 types of collagen membranes (cross-linked vs noncross-linked) used in conjunction with autogenous or allogenic bone followed by xenogeneic bone particles for dehiscence defect around implants in humans. Experimental groups were divided into 2 groups: Group CL (cross-linked, Ossix Plus, n = 24 implants, 16 patients) and Group NCL (noncross-linked, Bio-Gide, n = 25 implants, 18 patients). At the time of implant insertion and uncovery surgery, measurements of the dehiscence bony height, width, and surface area were made. Before applying the membrane to defects, guided bone regeneration was performed. Because it is difficult to measure the degree of exposure, early exposed cases were excluded from the result analysis. The mean percentage gain of the dehiscence defect and the mean marginal bone reduction value of follow-up radiograph did not show statistically significant differences between the 2 groups. Both membranes exhibited satisfactory results on dehiscence defects. As a result, our authors concluded the success of guided bone regeneration was performed simultaneously for dehiscence defects around the implant, regardless whether collagen membranes were cross-linked or noncross-linked.

Figure 1. Measurement of the depth from the most apical aspect of the bucco-lingual crestal bone to the implant platform margin (dehiscence height). Figure 2. Measurement of the mesiodistal length of the buccal bony defect (dehiscence width). Figure 3. Bone grafting performed with autogenous or allogenic bone applied over the exposed area followed by xenogenic bone particles. Figure 4. Application of resorbable collagen membrane was performed randomly. Figure 5. At the uncovery surgery, note the newly formed buccal area.

Figure 6. Intraoral radiograph during delivery of final restoration. Figure 7. Intraoral radiographs after 6 months of prosthetic loading.
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