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I C.E. article_ labial soft-tissue recession _about the author Dr. Bach Le completed specialty training in oral and maxillofacial surgery at Oregon Health Sciences University. He is currently clinical associate professor of oral and maxillofacial sur- gery at the Herman Ostrow School of Dentistry at USC, where he has been an ac- tive faculty member since 2000. Le has lectured inter- nationally on bone regen- eration and dental implant- related surgery and has taught on six continents. He has authored or co- authored more than 13 chapters in textbooks on bone regeneration and dental implants and has published extensively in journals. Le peer-review served as editor of the dental implant section of the recognized Fonseca Oral & Maxillofacial Surgery textbook (third edition), re- leased in 2017. His primary focus has been in hard- and soft-tissue regeneration im- proving esthetic outcomes. He has been a main- podium speaker at numer- ous organizations, includ- ing the American Associa- tion of Oral and Maxillofacial Surgeons, the Academy of Osseointegration, the American Academy of Es- thetic Dentistry, American Academy of Implant Den- tistry, the American College of Prosthodontists, the Greater New York Acad- emy of Prosthodontists and the International Con- gress of Oral Implantolo- gists. Le was inducted as an honorary member of the American College of Pros- thodontists in 2014 and is a recipient of the Charles E. English Award in Clini- cal Science for “the most significant article” published in the Journal of Implant Dentistry for 2008. He is a diplomate of the Ameri- can Association of Oral and Maxillofacial Surgeons, the American Dental Society of Anesthesiologist and the In- ternational Congress of Oral Implantologists. Fig. 16 Fig. 17 Fig. 16_Eight years follow-up. Fig. 17_13 years follow-up, illustrating continued tissue stability. Figs. 18-20_CBCT and periapical views at eight years after GBR procedure. showing stable bone and healthy tissue thickess around both implants. Fig. 18 Fig. 19 Fig. 20 anterior maxilla after increasing the thickness of the facial bone through GBR. Furthermore, the membrane placed over the par- ticulate graft in the present clinical case was essentially a collagen matrix similar to a connective tissue graft, which adds to the thickness of the overlying tissue.35 Scoring of the periosteum and underlying bone tis- sue prior to grafting and foreign body reaction from placement of a graft and membrane may also result in scar tissue formation that augments the soft-tissue profile. The present technique is not ideal for restoring the gingival margins for poorly positioned implants or when there is significant thread exposure. For example, implants placed outside of the alveolar housing or with significant labial inclination associated with labial bone loss should be excluded. Zucchelli et al.36 reported on a surgical-prosthetic treatment for implants with buccal soft-tissue de- hiscence defects in the esthetic zone. The technique involved removing the crown, shortening the abutment and then treating the dehiscence defect with a coronally advanced flap and connective tissue graft.36 After one year, mean soft-tissue dehiscence coverage was 96.3 percent with complete coverage in 75 percent of the treatment sites.36 While patients were satisfied during short-term follow-up, the ability to camouflage a bony defect with or without exposed implant threads is highly limited without the support of the underlying bone, which is the main cause of soft-tissue recession.24, 37-38 In addition to soft-tissue recession, marginal bone loss has been associated with increased peri-implant stress concentrations in the crestal bone region. Over time, elevated stress concentrations can trigger ad- ditional bone loss and further soft-tissue recession.39 If left untreated, increased stresses can result in screw loosening, metal fatigue and component fracture over time.39-40 Implants placed in the anterior maxillary jaw with thin buccal plates are highly susceptible to the adverse effects of marginal bone loss.39-40 In summary, the use of a mineralized bone allograft and a collagen membrane effectively increased alveolar hard- and soft-tissue dimensions in the esthetic zone of the anterior maxilla. Restoring the missing buccal bone decreased the risk of developing peri-implantitis from bacterial biofilm attachment to the exposed implant- abutment crevice and roughened implant surface. Secondly, the soft-tissue thickness was increased, which made the restored tissues more resistant to future recession and mask the underlying titanium components.31,40-41 Thirdly, guided bone regeneration also unexpectedly increased the width of keratinized tissue, which has also been reported to help provide a peri-implant soft-tissue seal against bacterial invasion, in addition to providing resistance against recession.33 While increases in soft-tissue thickness and kerati- nized tissue width have been reported after placement of connective tissue and free gingival grafts,33 this phe- nomena has not been previously reported after guided bone regeneration procedures around dental implants. The author has reported the results of using this same technique in 11 patients who achieved similar outcomes after short-term follow-up.14 The value of individual clinical case reports is that their anecdotal data can provide preliminary evidence for developing new hypotheses that lead to larger ran- domized clinical trials,42 which are needed to determine if the present approach will effectively serve as an alter- native for soft-tissue augmentation in instances where tissue thickening is needed._ References available upon request from the publisher. 08 I implants 1_2018