Osteotome-Induced Blood Clot and Subsequent Bone Formation with the Use of Collagen Sponge for Integration of Single Dental Implants into the Atrophied Posterior Maxilla: A Retrospective Follow-Up of 36 Implants after 5 to 13 years

Background. Atrophy of the posterior maxilla as a consequence of tooth loss and sinus pneumatization is a frequent condition encountered in the clinical practice. Prosthetic rehabilitation with implants in these patients often requires some kind of bone regeneration procedure to increase the bone volume. Aim. The aim of the present retrospective study is to analyze the survival and success rates of a series of implants placed in the atrophic posterior maxilla with a transcrestal osteotome procedure, without placing a bone grafting material. Materials and Methods. From 2006 to 2014, 36 dental implants (Neoss Ltd., Harrogate, UK) were inserted in 36 patients with at least 4 mm of bone below the maxillary sinus using transcrestal osteotome sinus floor elevation and placement of collagen sponge below the sinus membrane. ISQ measurements were made after implant placement and at abutment surgery after 4 to 6 months. The vertical bone height (VBH) was evaluated in intraoral radiographs taken prior to surgery and in radiographs from annual check-up appointments 5 to 13 years after implant placement. In addition, marginal bone loss (MBL) was evaluated. Results. One implant was lost after four years of prosthetic loading. The remaining 35 implants showed no complications and were loaded with single crowns after 4–6 months of healing. All 35 implants showed clinical success after 8.5 ± 2.8 years of prosthetic loading (from 5 to 13 years). The vertical bone height was 5.9 ± 1.4 mm at surgery, 9.7 ± 1.1 mm at second surgery after 4–6 months, and 8.3 ± 1.8 at the follow-up at 8.5 ± 2.8 years (from 5 to 13 years). The implant stability registered was 73.2 ± 6.2 ISQ at the surgery and 75.8 ± 3.9 at the second surgery after 4–6 months. Conclusions. The present long-term follow-up study showed that the crestal approach for sinus floor bone augmentation without additional bone grafting results in predicable bone formation and high implant survival. The osteotome technique is a valid alternative to the more invasive lateral window technique in single cases with a minimum of 4 mm of VBH below the maxillary sinus.

Transplantation of collagen sponge-based three-dimensional neural stem cells cultured in the RCCS system facilitate locomotor functional recovery in spinal cord injury animals

Numerous studies have indicated that microgravity induces various changes in the cellular functions of neural stem cells (NSCs), and the use of microgravity to culture tissue engineering seed cells for...

Endodontic Perforation Closure by Five Mineral Oxides Silicate-Based Cement with/without Collagen Sponge Matrix

Endodontic perforations are common accidents that occasionally happen as a result of misuse or difficult anatomy of some teeth; it may lead to teeth loss unless a good management is provided. Bioceramic (silicate-based) cements like mineral trioxide aggregate have a big role in management of such accidents. This case report aimed to evaluate the ability of five mineral oxides cement “5MO” in sealing two root canal perforations (furcation and postdrill perforations) and inducing clinical and radiographic healing in the periodontal tissues with/without the use of collagen sponge matrix. A 58-year-old healthy female was referred to our dental office complaining of severe pain in the upper left premolars’ region. Periapical radiographic examination revealed unsatisfactory root canal treatment of the teeth #24 and #25 with a furcation perforation and a postdrill perforation, respectively. Cone-beam computed tomography “CBCT” scans confirmed the findings of the periapical radiography and revealed the presence of radiolucent lesions surrounding the apex of both teeth #24 and #25. The treatment plan was a nonsurgical root canal retreatment by endodontic access through the full-ceramic crowns. After three years of follow-up, CBCT scans revealed a complete healing and bone formation on both premolars. This case report indicates the use of 5MO cement for endodontic perforations management.

BMP-2 Promotes Bone Formation in Bone Defects in Which Bone Remodeling Is Suppressed by Long-Term and High-Dose Zoledronic Acid

Background: The use of long-term and high-dose bisphosphate is associated with severely suppressed bone turnover and the delayed union of fractures. However, therapeutic methods to overcome the negative effects of bisphosphonate use are lacking. Bone morphogenetic proteins (BMPs) are powerful osteoinductive proteins. We hypothesized that BMPs had similar effects as autografts in patients with decreased bone healing potential due to long-term bisphosphonate treatment. The purpose of this study was to compare BMPs with demineralized freeze-dried bone grafts and autografts in a rat femoral bone defect model with long-term and high-dose bisphosphonate treatment. Methods: Forty rats were divided into the following four groups depending upon the materials implanted into the femoral defect after ten weeks of bisphosphonate (zoledronic acid) injections: Group I: absorbable collagen sponge (control); group II: demineralized freeze-dried bone graft; group III: autogenous bone graft; and group IV: rhBMP-2 with an absorbable collagen sponge. Radiographic union, micro computed tomography (CT) analysis, manual palpation, and histologic analysis were evaluated. Results: The radiographic union rate, manual union rate, and micro-CT bone volume in groups III and IV were significantly higher than those in groups I and II. Groups III and IV showed similar results to each other. Although the amount of immature bone in the BMP-treated group was large, the effect was similar to that of autografts in the bone defect model in which bone turnover was severely reduced by bisphosphonate treatment. Conclusion: BMP might be a good substitute for autografts in patients with decreased bone healing potential due to long-term bisphosphonate treatment.

Bone remodeling around implants placed after socket preservation: a 10-year retrospective radiological study

Background To evaluate and compare the long-term clinical and radiological outcomes of post-extraction sockets after ridge preservation either with porcine xenograft or collagen alone. Patients underwent single-tooth extraction in the posterior mandible. Fresh extraction sockets were filled with pre-hydrated cortico-cancellous porcine bone or collagen sponge. Two or 3 months later, a ridge expansion technique with immediate implant positioning placement was performed. Primary (alveolar width changes) and secondary outcomes (adverse events and long-term maintenance of buccal plate covering the implant) were evaluated. Results Thirty-four women and 20 men were selected: 30 implants (group A) placed into healed post-extraction sockets grafted with porcine bone and 24 (group B) into sockets filled with a collagen sponge. There was a significant loss in width in both groups from the first and second surgery (ranging between 2.7 mm and 4.5 mm). The ridge splitting with bone expansion resulted in significant long-term increases in width for both procedures and implant sites. Non-significant differences in alveolar width were registered between the groups at 10-year follow-up even if the analysis of the implant buccal bone coverage suggested that group A had significantly worst results. Conclusions Porcine bone group had significantly better short-term outcomes with lower long-term maintenance of the buccal plate.