Immediate loading with a novel implant featured by variable-threaded geometry, internal conical connection and platform shifting: three-year results from a prospective cohort study

PURPOSE

To evaluate the clinical and radiological performance of an immediately loaded novel implant design over a 3-year period.

MATERIALS AND METHODS

This prospective study includes 54 consecutive partially edentulous patients treated between December 2010 and October 2011. Outcome measures were: implant and prosthetic failures; biological and mechanical complications; marginal bone loss (MBL); sulcus bleeding index (SBI); and plaque score (PS).

RESULTS

A total of 118 (29 narrow platform, 70 regular platform and 19 wide platform) NobelReplace Conical Connection implants were placed in both post-extraction sockets and healed sites and immediately loaded. The mean insertion torque was 63.4 ± 7.1 Ncm. One hundred out of 118 implants (84.7%) were inserted with a torque ranging between 55 and 70 Ncm. Each patient received a single prosthesis. At the 3-year follow-up, no patient dropped out and only two post-extractive implants failed (1.7%) in two patients (3.7%). The only complication (1.9%) observed was an event of periimplantitis, consisting of a mean mesiodistal peri-implant bone loss of 3.2 mm reported in a healed site of a smoker patient at the 2-year follow-up examination. No prosthesis failures were detected. The cumulative mean MBL between implant placements at the 3-year follow-up was 0.68 mm (95% CI: 0.44, 0.92). At the 3-year follow-up session, the SBI and PS were 5.7% and 15.4%, respectively.

CONCLUSIONS

The NobelReplace Conical Connection implant can be considered as a valuable treatment option for immediate implant placement and loading in the partially edentulous patients over a 3-year period. Insertion torques ranging between 55 and 70 Ncm are not detrimental to osseointegration.

The effectiveness of a resorbable bone substitute with a resorbable membrane in the treatment of periodontal infrabony defect - A multicenter randomised controlled trial

PURPOSE

To evaluate the effectiveness of a bone substitute covered with a resorbable membrane versus open flap debridement for the treatment of periodontal infrabony defects.

MATERIALS AND METHODS

Ninety-seven patients with one infrabony defect, which was 3 mm or deeper and at least 2 mm wide were randomly allocated either to grafting with a bone substitute covered with a resorbable barrier (BG group) or open flap debridement (OFD group) according to a parallel group design in five European centres. Blinded outcome measures assessed tooth loss, complications, patient's satisfaction with treatment and aesthetics, changes in probing attachment levels (PAL), probing pocket depths (PPD), gingival recessions (REC), radiographic bone levels (RAD) on standardised periapical radiographs, plaque index (PI) and marginal bleeding index (MBI).

RESULTS

49 patients were randomly allocated to the BG group and 48 to the OFD group. At baseline there were more mobile teeth in the BG group (29 versus 15). One year after treatment two patients dropped out from the BG group and no teeth were lost. Three complications (minor postoperative wound dehiscence) occurred in the BG group versus none in the OFD group, where the difference was not statistically significant. The BG group obtained significantly greater statistical PAL gain (mean difference = -0.8 mm, 95% CI [-1.51; -0.03], P = 0.0428), PPD reduction (mean difference = -1.1 mm, 95% CI [-1.84; -0.19], P = 0.0165) and RAD gain (mean difference = -1.2 mm, 95% CI [-2.0; -0.4], P = 0.0058) compared to the OFD group. No statistically significant differences between the groups were observed for gingival recession, or the patient's satisfaction with the treatment and aesthetics. There were some statistically significant differences between the centres for PAL and PPD with the Italian centres reporting better outcomes.

CONCLUSIONS

The use of a bone substitute covered with a resorbable membrane yielded significantly better statistical clinical outcomes than open flap debridement in the treatment of periodontal infrabony defects deeper than 3 mm, with regard to PAL gain, PPD reduction and RAD gain.

Comparing membranes and bone substitutes in a one-stage procedure for horizontal bone augmentation. A double-blind randomised controlled trial

PURPOSE

The objective of this parallel randomised controlled trial is to compare two bone substitutes and collagen membranes in a one-stage procedure for horizontal bone augmentation: anorganic bovine bone (Bio-Oss) and collagen porcine membranes (Bio-Gide) (BB group) versus a synthetic resorbable bone graft substitute made of pure β-tricalcium phosphate (Ceros TCP) and porcine pericardium collagen membranes (Jason) (CJ group).

MATERIALS AND METHODS

Patients in need of implant treatment having at least one site with horizontal osseous defects at a private clinic in Rimini (Italy) were included in this study. Patients were randomised to receive either the BB or CJ treatment. Randomisation was computer-generated with allocation concealment by opaque sequentially numbered sealed envelopes. Patients and the outcome assessor were blinded to group assignment. The main outcome measures were implant failure, complications, clinical bone gain at augmented sites, and complete filling of the bone defect. Secondary outcome measures were chair-time, postoperative pain and peri-implant marginal bone level changes.

RESULTS

Twenty-five patients with 32 implants were allocated to the BB group and 25 patients with 29 implants to the CJ group. All 50 randomised patients received the treatment as allocated and there were no dropouts up to 6-months post-loading (12 months post-surgery). There were no failures and there were three complications in the BB group and three complications in the CJ group (relative risk: 1.00, 95% CI from 0.22 to 4.49, P = 1.00). The estimated difference between treatments in the vertical defect bone gain was -0.15 mm (95% CI from -0.65 to 0.35, P = 0.5504) favouring the BB group, and the estimated difference between treatments in the horizontal defect bone gain was -0.27 mm (95%CI from -0.73 to 0.19, P = 0.3851) favouring the BB group. There was no difference in the complete filling of the defect (relative risk: 0.88, 95%CI from 0.58 to 1.34, P = 0.7688). No significant differences were detected for chair-time (P = 0.3524), for VAS pain immediately after surgery (P = 0.5644), VAS pain after 1 week (P = 0.5074) and VAS pain after 2 weeks (P = 0.6950). A slight difference (0.24 mm, 95%CI from 0.0004 to 0.47, P = 0.0464) was detected in radiographic peri-implant bone loss favouring the CJ group.

CONCLUSIONS

No significant differences, except for radiographic bone loss, were observed in this randomised controlled trial comparing anorganic bovine bone with collagen porcine membranes versus synthetic resorbable bone made of pure β-tricalcium phosphate with pericardium collagen membranes for horizontal augmentation.

Short implants as an alternative to crestal sinus lift: A 1-year multicentre randomised controlled trial

PURPOSE

To evaluate the efficacy of short (5 or 6 mm-long) dental implants versus 10 mm or longer implants placed in crestally-lifted sinuses.

MATERIALS AND METHODS

Twenty partially edentulous patients having 5 to 7 mm of residual crestal height and at least 7 mm thickness below the maxillary sinuses as measured on computerised tomography scans were randomised according to a parallel group design to receive either one to two 5 or 6 mm-long implants (10 patients) or 10 mm-long implants (10 patients) after crestal sinus lifting and grafting with anorganic bovine bone (Endobon). Implants were left to heal submerged for 4 months and loaded with reinforced acrylic provisional prostheses, and then replaced after 4 months, by definitive provisionally cemented or screw-retained metal-ceramic or metal-resin prostheses. Outcome measures were prosthesis and implant failures, any complications, radiographic peri-implant marginal bone level changes and patient's satisfaction assessed by blinded assessors, when possible. All patients were followed up to 1 year after loading.

RESULTS

No patient dropped out, no failures or complications occurred. Short implants lost 0.70 ± 0.19 mm of peri-implant marginal bone and long implants lost 0.87 ± 0.21 mm of periimplant marginal bone 1 year after loading, the difference between the two groups showing no statistical significance (difference = -0.17 mm; 95% CI: -0.35 to 0.02; P = 0.078).

CONCLUSIONS

Both techniques achieved excellent results and no differences were observed between prostheses supported by one to two implants, 5 to 6 mm-long or 10 mm-long in the posterior atrophic maxillae up to 1-year after loading, therefore it is up to the clinicians to decide which procedure to use, although longer follow-ups are needed to understand if one of these procedures could be more effective in the long-term.

Group C. Initiator paper. Periodontal regeneration--fact or fiction?

Numerous techniques have been tried and tested to regenerate tissues lost to periodontal disease. While there has been some success to date, more work is required to move this to a reliable and clinically predictable procedure. Much of the future success for such treatments will rely largely on our understanding of the biology of both developmental and regenerative processes. Nonetheless, despite the noble goal of periodontal regeneration, the relevance of re-creation of a connective tissue attachment has been questioned. Since formation of a long junctional epithelial attachment to the tooth following a variety of periodontal treatment procedures has been shown to be no more susceptible to further breakdown than a non-diseased site, the question arises as to what purpose do we seek the ultimate outcome of periodontal regeneration? The answer lies in the "fact and fiction" of periodontal regeneration. There is no doubt that the regenerative procedures that have been developed can be shown to be biologically successful at the histological level. Furthermore, the results of periodontal regeneration (particularly guided tissue regeneration) have been stable over the long term (at least up to 10 years). However, the techniques currently under use which show the greatest promise (guided tissue regeneration and growth factors) are still clinically unpredictable because of their highly technique-sensitive nature. In addition, whether the slight clinical improvements offered by these procedures over routine open flap debridement procedures are of cost or patient benefit with regards to improved periodontal health and retention of teeth remains to be established. The next phase in regenerative technologies will undoubtedly involve a deeper understanding of the molecular signaling (both intra- and extra-cellular) and cellular differentiation processes involved in the regenerative processes. So in answer to the question of whether periodontal regeneration is fact or fiction, the answer clearly is that it is both. However, with more work it will become established fact with little fiction and the desired clinical endpoint of predictable regeneration of the periodontal tissues damaged by inflammation to their original form and function will be achieved.

Immediate non-occlusal loading of immediate post-extractive versus delayed placement of single implants in preserved sockets of the anterior maxilla: 1-year post-loading outcome of a randomised controlled trial

PURPOSE

To compare the effectiveness of immediate post-extractive single implants with delayed implants placed in preserved sockets after 4 months of healing. Implants that achieved an insertion torque of at least 35 Ncm were immediately non-occlusally loaded.

MATERIALS AND METHODS

Just after tooth extraction, and in the presence of less than 4 mm of vertical loss of the buccal bone in relation to the palatal wall, 50 patients requiring a single immediate post-extractive implant in the maxilla from second to second premolar were randomly allocated for either immediate implant placement (immediate group; 25 patients) or for socket preservation using an algae-derived (phycogenic) bone substitute, covered by a resorbable collagen barrier (delayed group; 25 patients), according to a parallel group design in one centre. Bone-to-implant gaps were filled with an algae-derived bone substitute. Four months after socket preservation, delayed implants were placed. Implants inserted with an insertion torque of at least 35 Ncm were immediately loaded with non-occluding provisional single crowns, then replaced, after 4 months, by definitive crowns. Patients were followed up to 1 year after loading. Outcome measures were implant failures, complications, aesthetics assessed using the pink esthetic score (PES), peri-implant marginal bone level changes and patient satisfaction, recorded by blinded assessors.

RESULTS

Nine (36%) implants were not immediately loaded in the immediate group versus 19 (76%) implants in the delayed placement group, because an insertion torque superior to 35 Ncm could not be obtained, the difference being statistically significant (difference = - 0.40, 95% CI: -0.652 to -0.148, P = 0.010). Two patients dropped out 4 months after loading in the delayed group versus none in the immediate group. Two implants failed in the immediate group (8%) versus none in the delayed group, with the difference showing no statistical significance (considering 25 and 23 patients, the difference in proportions was 8% favouring the delayed group, 95% CI: -8.4 to 26.0, P = 0.490). Three minor complications occurred in the immediate group and two in the delayed group, and this was not statistically significant (considering 25 and 23 patients, the difference in proportions was 3.3% favouring the delayed group, 95% CI: -18.2 to 24.0, P = 1.000). At delivery of definitive crowns, 4 months after loading, the mean aesthetic score was 12.42 and 12.28 in the immediate and delayed groups, respectively. At 1 year after loading, the mean aesthetic score was 12.78 and 12.22 in the immediate and delayed groups, respectively. There were no statistically significant differences at 4 months (P = 0.666) and at 1 year (P = 0.090). Marginal bone levels at implant insertion (after bone grafting) were 0.01 mm for immediate and 0.06 mm for delayed implants, which showed a statistically significant difference (mean difference = - 0.04; 95% CI: -0.08 to -0.01; P = 0.009). One year after loading, patients of the immediate group lost on average 0.13 mm marginal bone and those in the delayed group lost 0.19 mm, however the difference was not statistically significant (mean difference = 0.05; 95% CI: -0.002 to 0.110; P = 0.06). All patients were fully satisfied, both for function and aesthetics, and would undergo the same procedure again at 4 months as well as at 1 year after loading.

CONCLUSIONS

No significant differences were observed between the two procedures, although the only two implant failures were for immediate post-extractive implants. It seems more difficult to obtain an implant insertion torque superior to 35 Ncm in sockets preserved with algae-derived bone substitute after a 4-month healing period than at immediate post-extractive sites.

Osteoconductive property of a mechanical mixture of octacalcium phosphate and amorphous calcium phosphate

The present study was designed to investigate the extent of osteoconductive property of a mechanical mixture of octacalcium phosphate (OCP) and amorphous calcium phosphate (ACP). OCP was mixed with ACP in granules that had a diameter of 300 and 500 μm, respectively, and at 25, 50, or 75 wt %. The physicochemical characteristics and the osteoconductive properties of the mixtures were compared with OCP alone or ACP alone through implantation into rat critical-sized calvaria defects for up to 12 weeks and simulated body fluid (SBF) immersion for 2 weeks. The mixtures of OCP and ACP, in particular the OCP 25 wt % and ACP 75 wt % (O25A75), had higher radiopacity compared to ACP and OCP alone. O25A75 induced greater enhancement of bone regeneration than ACP alone at 8 weeks and that than OCP alone at 12 weeks. X-ray diffraction and Fourier transform infrared (FTIR) analyses of the retrieved mixtures showed that ACP, OCP, and O25A75 tended to convert to hydroxyapatite (HA) after the implantation, while the structure of OCP remains without complete conversion after SBF immersion. Analyses by FTIR curve fitting of the solids and the degree of supersaturation of the SBF supported the observation that the existence of ACP enhances the kinetics of the conversion. Scanning electron microscopy found that the surface of O25A75 had distinct characteristics with OCP and ACP after SBF immersion. The results suggest that the extent of the osteoconduction of OCP could be controlled by the copresence of ACP most probably through the prevailing dissolution-precipitation of the surface of ACP crystals to form HA.

A prospective randomized comparison of PEEK cage containing calcium sulphate or demineralized bone matrix with autograft in anterior cervical interbody fusion

PURPOSE

A variety of bone substitutes have been successfully used to fill PEEK cages in cervical interbody fusion in order to avoid the complications related to bone harvesting from the donor site. However, no controlled study has previously been conducted to compare the effectiveness of PEEK interbody cages containing calcium sulphate/ demineralized bone matrix (CS/DBM) with autogenous cancellous bone for the treatment of cervical spondylosis. The objective of this prospective, randomized clinical study was to evaluate the effectiveness of implanting PEEK cages containing CS/DBM for the treatment of cervical radiculopathy and/or myelopathy.

METHODS

Sixty-eight patients with cervical radiculopathy and/or myelopathy were randomly assigned to receive one- or two-level discectomy and fusion with PEEK interbody cages containing CS/DBM or autogenous iliac cancellous bone (AIB). The patients were followed up for two years postoperatively. The radiological and clinical outcomes were assessed during a two-year follow-up.

RESULTS

The mean blood loss was 75 ± 18.5 ml in the CS/DBM group and 100 ± 19.6 ml (P < 0.01) in the AIB group. The fusion rate was 94.3 % in the CS/DBM group and 100 % in the AIB group at 12-month follow-up. The fusion rate was 100 % at final follow-up in both groups. No significant difference (P > 0.05) was found regarding improvement of JOA score and segmental lordosis as well as neck and arm pain at all time intervals between the two groups. The total complication rate was significantly higher (P < 0.05) in the AIB group than in the CS/DBM group, but there was no significant difference between the two groups (P > 0.05) when comparing the complications in the neck.

CONCLUSIONS

In conclusion, the PEEK interbody fusion cage containing CS/DBM or AIB following one- or two-level discectomy had a similar outcome for cervical spondylotic radiculopathy and/or myelopathy. The rate of fusion and the recovery rate of JOA score between the two groups were the same. The filling of CS/DBM in the PEEK cage instead of AIB has the advantage of less operative blood loss and fewer complications at the donor site.

Novel unidirectional porous hydroxyapatite used as a bone substitute for open wedge high tibial osteotomy

PURPOSE

The purpose of this study was to clinically and radiologically evaluate the availability, osteoconductivity, and resorption of a novel unidirectional porous hydroxyapatite (UDPHAp) used as an artificial substitute for open wedge high tibial osteotomy (OWHTO). Our hypothesis was that UDPHAp is a safe and useful bone substitute for OWHTO.

MATERIALS AND METHODS

Seven patients (2 men and 5 women aged 34-72years) who underwent OWHTO and were followed up for more than 12months were retrospectively studied. After the osteotomy, the gap created was filled with UDPHAp(REGENOS® Kuraray Co.Ltd). Radiography and computed tomography(CT) were performed, and gap healing was assessed postoperatively. The Japanese Orthopaedic Association (JOA) knee score was determined pre- and post-operatively for clinical evaluation.

RESULTS

Neither gross displacement nor collapse of the UDPHAp block graft was observed within 12 months after surgery. Both radiographs and CT showed attenuation of lucency and increasing sclerosis over time. JOA score improved from 71.2 (65-80) to 95.8 (85-100).

CONCLUSIONS

Short term results for OWHTO using UDPHAp was satisfactory. Clinical improvement of JOA scores were seen, besides osteogenesis was progressing in and around the artificial bone grafts.

An evaluation and comparison of the efficacy of nanocrystalline calcium sulfate bone grafts (NanoGen) and medical-grade calcium sulfate bone grafts (DentoGen) in human extraction sockets

BACKGROUND

Grafting a fresh extraction socket is essential for successful regeneration of bone and maximizing volume preservation. Various synthetic grafts have been used to simulate bone formation. The purpose of the present study was to evaluate clinical, histomorphometric, and radiographic healing at 1-month, 3-month, and 4-month time points after tooth extraction with placement of calcium sulfate hemihydrate putty bone grafts NanoGen and DentoGen to determine their efficacy in ridge preservation following tooth extraction.

METHOD

Sixty subjects who were in need of extraction were recruited. The subjects were randomly assigned their group based on computer software for both the test groups (NanoGen and DentoGen). DentoGen is a medical-grade calcium sulfate hemihydrate with particle of 30 µm, and NanoGen is a nanocrystalline version of DentoGen with particle size 400 µm to 800 µm. Data were recorded at 1, 3, and 4 months after extraction socket grafting. Bone biopsies were taken at 4 months for histomorphometric analysis.

RESULTS

The mean percentage of bone formed by NanoGen was 51.19 ± 9.53% and by DentoGen 50.67 ± 16.16% after 4 months. No statistically significant difference was noted in the mean bone formation by NanoGen and DentoGen at various time intervals; no bone graft remnants of DentoGen were found at 4 months. The mean percentage of bone graft remnants left after 4 months for NanoGen was 6.83 ± 16% in the maxilla and 7.38 ± 21% in the mandible. The mean percentage of soft tissue formed was significantly higher with DentoGen in mandibular socket sites. On radiographic evaluation the mean percentage of socket fill with DenoGen was found to be 23.1 ± 11.65%, 50 ± 9.6%, and 76.7 ± 11% and with NanoGen was 29.2 ± 12.8%, 52.8 ± 15.6%, and 76.47 ± 12.43% at 1 month, 3 months, and 4 months postoperative intervals, respectively.

CONCLUSION

Both the materials investigated in the study showed excellent bone forming capacity, but the nanocrystalline version (NanoGen) of calcium sulfate was found to have clinical and biologic advantages over DentoGen.

Extraction site preservation using an in-situ hardening alloplastic bone graft substitute

This case report highlights the use of an in-situ hardening alloplastic bone grafting material composed of beta-tricalcium phosphate (β-TCP) granules coated with poly(lactic-co-glycolic acid) (PLGA) to preserve the dimensions and architecture of the alveolar ridge after atraumatic extraction. This material provided a stable scaffold that, although left uncovered, deterred the ingrowth of unwanted soft tissue, allowing newly formed keratinized soft tissue to proliferate over the healing grafted socket and gradually cover the site. At re-entry after 4 months adequate newly formed bone was observed, allowing for the correct positional placement of an implant. The results of this case suggest that an in-situ hardening alloplastic grafting material can be successfully utilized with minimally invasive procedures to preserve the bone and the soft-tissue profile of the alveolar ridge for future implant rehabilitation.

Bone substitutes in orthopaedic surgery: from basic science to clinical practice

Bone substitutes are being increasingly used in surgery as over two millions bone grafting procedures are performed worldwide per year. Autografts still represent the gold standard for bone substitution, though the morbidity and the inherent limited availability are the main limitations. Allografts, i.e. banked bone, are osteoconductive and weakly osteoinductive, though there are still concerns about the residual infective risks, costs and donor availability issues. As an alternative, xenograft substitutes are cheap, but their use provided contrasting results, so far. Ceramic-based synthetic bone substitutes are alternatively based on hydroxyapatite (HA) and tricalcium phosphates, and are widely used in the clinical practice. Indeed, despite being completely resorbable and weaker than cortical bone, they have exhaustively proved to be effective. Biomimetic HAs are the evolution of traditional HA and contains ions (carbonates, Si, Sr, Fl, Mg) that mimic natural HA (biomimetic HA). Injectable cements represent another evolution, enabling mininvasive techniques. Bone morphogenetic proteins (namely BMP2 and 7) are the only bone inducing growth factors approved for human use in spine surgery and for the treatment of tibial nonunion. Demineralized bone matrix and platelet rich plasma did not prove to be effective and their use as bone substitutes remains controversial. Experimental cell-based approaches are considered the best suitable emerging strategies in several regenerative medicine application, including bone regeneration. In some cases, cells have been used as bioactive vehicles delivering osteoinductive genes locally to achieve bone regeneration. In particular, mesenchymal stem cells have been widely exploited for this purpose, being multipotent cells capable of efficient osteogenic potential. Here we intend to review and update the alternative available techniques used for bone fusion, along with some hints on the advancements achieved through the experimental research in this field.

Effect of different hydroxyapatite:β-tricalcium phosphate ratios on the osteoconductivity of biphasic calcium phosphate in the rabbit sinus model

PURPOSE

This study compared the volume stability and bone-forming capacity of biphasic calcium phosphate (BCP) with a high versus a low ratio of (β-tricalcium phosphate (β-TCP) relative to hydroxyapatite (HA), i.e., 70:30 vs 30:70, in the rabbit sinus model.

MATERIALS AND METHODS

Bilateral sinus windows were created in eight adult New Zealand white rabbits (2.5 to 3.5 kg); each sinus in each rabbit was assigned to one of two experimental BCP groups according to the HA: β-TCP ratio. One sinus was grafted with BCP with a high ratio of β-TCP (30:70; TCP70), and the contralateral sinus was grafted with BCP with a low ratio of β-TCP (70:30; TCP30). The animals were sacrificed after 2 weeks (n = 4) or 8 weeks (n = 4) of healing. Biopsy specimens were harvested and evaluated histologically, histomorphometrically, and with microcomputed tomography.

RESULTS

The bone volume did not differ significantly between the two groups at each healing point, or between 2 and 8 weeks of healing in both groups. The amount of new bone increased significantly between 2 and 8 weeks of healing in both groups, and it did not differ significantly between the TCP30 and TCP70 groups. The residual material was significantly more resorbed in the TCP70 group than in the TCP30 group at both 2 and 8 weeks. In the TCP70 group, a greater number of multinucleated giant cells were observed at both weeks. The bone-to-residual material contact ratio did not differ significantly between the two groups.

CONCLUSION

The volume stability and osteoconductive capacity of BCP with an HA: β-TCP ratio of 30:70 was comparable to that with an HA: β-TCP ratio of 70:30. Thus, within the limitations of this study, it can be argued that BCP with an HA: β-TCP ratio of 30:70 can be successfully used for sinus augmentation.

Mandible reconstruction using rhBMP-2: case report and literature review

Recombinant human bone morphogenetic protein-type 2 (rhBMP-2) is used in oral and maxillofacial procedures due to its endochondral bone formation capacity, and this is also the reason for its use off-label in jaw reconstruction. This study reports a case of an extensive central giant cell lesion along the mandibular body and symphysis. Treatment consisted of enucleation and curettage followed by off-label use of rhBMP-2 associated with bovine bone xenograft. The literature concerning mandibular reconstruction using rhBMP-2 was also reviewed.

Trends in bone graft use in the United States

Bone graft and bone graft substitutes are used to provide structural support and enhance bone healing. Autogenous, allogeneic, and artificial bone grafts each have advantages and drawbacks. The development of allografts, synthetic bone grafts, and new operative techniques may have influenced the use of bone grafts in recent years. The goal of this study was to analyze the use of bone grafts and bone graft substitutes in the United States during a 16-year period. Using data from the National Hospital Discharge Survey, the authors analyzed the use of autogenous and artificial bone grafts in almost 2 million patients in the United States between 1992 and 2007 using International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes in 4 periods (1992-1995, 1996-1999, 2000-2003, and 2004-2007). Among an estimated almost 2 million bone graft procedures (83% autogenous, 17% artificial), the use of both types of grafts decreased. The main diagnoses for which bone grafts were used did not change; however, cervical spine diseases and lower-limb fractures decreased more remarkably. Although sex (52% male in the early 1990s to 47% in 2000-2003) and discharge status (more discharges to a short-term or long-term-care facility) significantly changed, age increased from 47 to 53 years and inpatient days decreased significantly from 6 to 5 days during the study period. The use of bone grafts and bone graft substitutes is decreasing in the United States, with a slight shift from autogenous to substitute grafts.

Endoscopic lift of the maxillary sinus floor in Beagles

The aim of this study was to introduce a modified endoscopic lift of the floor of the maxillary sinus in Beagles. Twelve operations (bilateral and randomly chosen) were done in 6 Beagles each in the test group (modified endoscopic operation), and the control group, in which the operation was done with an osteotome. All operations were evaluated by two indices of safety (perforation of the sinus membrane and nasal bleeding) and 3 effective indices (the intraoperative height after lifting, volume of bone grafts, and dislocation of the sinus grafts). The sinus membrane was not perforated and there were no nasal bleeds in either group. The intraoperative height after lifting was 13.7 (0.8) mm in the test group and 9.1 (0.5) mm in the control group, so it was significantly higher in the test group than the control group (p=0.0001). Similarly, the volume of bone graft was 0.9 (0.04) ml in the test group and 0.5 (0.02) ml in the control group (p=0.0001). The volume of the anterior and posterior bone grafts in the implant cavity in the test group did not differ significantly (p=0.102), while there were significant differences in the control group (p=0.002). Endoscopic lifting of the floor of the maxillary sinus is a safe and effective approach based on direct observation in Beagles.

Bio-Oss(®) for delayed osseointegration of implants in dogs: a histological study

We evaluated the effects of Bio-Oss® (a natural bone substitute derived from the mineral portion of bovine bone) on delayed osseointegration of implants. The bilateral third and fourth mandibular premolars of 4 adult, healthy, male and female dogs were extracted. We randomly selected 2 extraction sockets in each dog to be filled with Bio-Oss® (the experimental group); the other 2 extraction sockets, which were not treated, served as controls. Dental implants were inserted into the alveolar bone of the experimental group and the control group 3 months after insertion of the Bio-Oss®. The osteogenic activity in the bone around the implants was assessed by evaluating the histological morphology and estimating histomorphometric variables at 3 and 6 months after delayed implantation. After 3 months, Goldner's trichrome staining analysis showed that the rate of content between the bone and the implant and the mineralised area of bone around the implant were significantly higher in the experimental group (76%(9%) and 69.5% (9.6%), respectively) than those in the control group (56.1% (8.2%) and 52.8% (7.3%), respectively, p=0.003 and 0.000). However, the 2 groups did not differ significantly at 6 months. Fluorescence microscopy showed that the mean rates of mineralisation of the bony tissue around the implant in the experimental group at months 3 and 6 were 6.8 (0.4) μm and 8.4 (0.8) μm, respectively, which were significantly higher than those in the control group (p=0.000 and 0.03). These data indicate that putting Bio-Oss® into the extraction sockets can promote osseointegration after delayed implantation, and may be a promising option for clinical use.

Nasal floor elevation combined with dental implant placement: a long-term report of up to 86 months

PURPOSE

The aim of this paper is to present a large-scale long-term follow-up of dental implants placed simultaneously with nasal floor augmentation using osteoconductive bovine bone substitutes.

MATERIALS AND METHODS

Patients who received dental implants combined with nasal floor elevation in three dental centers between 2006 and 2012 were included in this report. Preoperative available bone height was measured on computed tomographic scans. Implant parameters as well as implant survival rates were recorded. The cohort consisted of long-term follow-up of this previously reported cohort, combined with a cohort of newly treated patients.

RESULTS

Overall, 67 patients were included in this study. Cigarette smoking was reported by 16 patients. Two hundred three implants were inserted in combination with nasal floor elevation. No nasal mucosa perforations were observed. The mean follow-up periods were 65.93 ± 13.2 months (range, 33 to 86 months) for the original cohort and 23.14 ± 9.4 months (range, 7 to 44 months) for the newly treated patients. The available bone height prior to bone augmentation was 8.89 ± 1.1 mm (range, 5 to 11.2 mm) and a mean of 3.65 ± 0.9 mm (range, 1.1 to 7 mm) of additional height was achieved with nasal floor elevation. During the follow-up period, no implants were lost, resulting in a 100% survival rate.

CONCLUSION

Nasal floor augmentation, as shown in this report, might serve as a reliable method for reconstruction of the anterior atrophic maxilla when residual height is insufficient.

Implant treatment in atrophic posterior mandibles: vertical regeneration with block bone grafts versus implants with 5.5-mm intrabony length

PURPOSE

To retrospectively compare the outcomes of implants placed in posterior mandibles vertically regenerated with onlay autogenous block bone grafts and short dental implants.

MATERIALS AND METHODS

Consecutive patients with vertical bone atrophy in edentulous mandibular posterior regions (7 to 8 mm of bone above the inferior alveolar nerve) were treated with either implants placed in regenerated bone using autologous block bone grafts (group 1) or short implants (with 5.5-mm intrabony length) in native bone (group 2) between 2005 and 2010 and followed for 12 months after loading. The procedure used was the established treatment protocol for this type of patient at the Oral Surgery Unit (University of Valencia, Spain) at the time of surgery. All grafts were obtained using piezosurgery. The outcomes assessed were: complications related to the procedure, implant survival, implant success, and peri-implant marginal bone loss. Statistical analysis was done using the Fisher exact test and the Mann-Whitney test.

RESULTS

Thirty-seven patients were included, 20 (45 implants) in group 1 and 17 (35 implants) in group 2. In group 1, 13 implants were less than 10 mm long (2 were 7 mm and 11 were 8.5 mm), and 32 were 10 mm or longer; the diameter was 3.6 mm in 6 implants, 4.2 mm in 31, and 5.5 mm in 8. In group 2 all implants were 7 mm long; the diameter measured 4.2 mm in 14 implants and 5.5 mm in 21 implants. Complications related to the block bone grafting procedure were temporary hypoesthesia in one patient, wound dehiscence with graft exposure in three patients, and exposure of the osteosynthesis screw without bone graft exposure in one patient. After 12 months, implant survival rates were 95.6% in group 1 and 97.1 % in group 2; success rates were 91.1% and 97.1%, respectively. The average marginal bone loss was 0.7 ± 1.1 mm in group 1 and 0.6 ± 0.3 mm in group 2.

CONCLUSIONS

When residual bone height over the mandibular canal is between 7 and 8 mm, short implants (with 5.5-mm intrabony length) might be a preferable treatment option over vertical augmentation, reducing chair time, expense, and morbidity.

A novel technique to prevent the loss of graft material through the antrostomy after sinus surgery: technical note

Maxillary sinus surgery has been shown to be a reliable procedure for increasing vertical bone height prior to implant placement. A variety of grafting materials have been proposed, with particulate bone substitutes showing similar clinical results to autogenous bone when rough surfaces implants are used. A barrier membrane is usually placed external to the grafted sinus, covering the antrostomy. In this technical report, the membrane is placed over the window and its borders gently tucked between the inner side of the bony wall and the graft material. This procedure stabilizes the membrane without tacks and prevents graft dislodgement through the antrostomy.

Stem cell engineered bone with calcium-phosphate coated porous titanium scaffold or silicon hydroxyapatite granules for revision total joint arthroplasty

Aseptic loosening in total joint replacements (TJRs) is mainly caused by osteolysis which leads to a reduction of the bone stock necessary for implant fixation in revision TJRs. Our aim was to develop bone tissue-engineered constructs based on scaffolds of clinical relevance in revision TJRs to reconstitute the bone stock at revision operations by using a perfusion bioreactor system (PBRS). The hypothesis was that a PBRS will enhance mesenchymal stem cells (MSCs) proliferation and osteogenic differentiation and will provide an even distribution of MSCs throughout the scaffolds when compared to static cultures. A PBRS was designed and implemented. Scaffolds, silicon substituted hydroxyapatite granules and calcium-phosphate coated porous TiAl6V4 cylinders, were seeded with MSCs and cultured either in static conditions or in the PBRS at 0.75 mL/min. Statistically significant increased cell proliferation and alkaline phosphatase activity was found in samples cultured in the PBRS. Histology revealed a more even cell distribution in the perfused constructs. SEM showed that cells arranged in sheets. Long cytoplasmic processes attached the cells to the scaffolds. We conclude that a novel tissue engineering approach to address the issue of poor bone stock at revision operations is feasible by using a PBRS.

Long-term in vivo experimental investigations on magnesium doped hydroxyapatite bone substitutes

Despite several efforts to find suitable alternatives to autologous bone, no bone substitute currently available provides the same characteristics and properties. Nevertheless, among the wide range of materials proposed as bone substitutes, calcium phosphate materials represent the most promising category and the present study is aimed at improving the knowledge on non-stoichiometric magnesium-doped hydroxyapatite substitutes (Mg-HA), tested in two different formulations: Mg-HA Putty and Mg-HA Granules. These bone substitutes were implanted bilaterally into iliac crest bone defects in healthy sheep and comparative histological, histomorphometric, microhardness and ultrastructural assessments were performed 9, 12, 18 and 24 months after surgery to elucidate bone tissue apposition, mineralization and material degradation in vivo. The results confirmed that the biomimetic bone substitutes provide a histocompatible and osteoconductive structural support, during the bone formation process, and give essential information about the in vivo resorption process and biological behavior of biomimetic bone substitutes.

Root amputation: a new look into an old procedure

A treatment option for managing furcation invasions is root amputation. Long-term survival of resected molars requires a complete harmony of sequential endodontic, periodontic, restorative and maintenance procedures. The main objective of this article is to provide a concise historical perspective of this procedure and to review available literature regarding its efficacy and limitations. It also illustrates a current modification of the procedure using guided bone regeneration (GBR) and socket preservation to eliminate some of the potential disadvantages of the traditional root amputation procedure.

Treatment of a mandibular cyst before implant placement: case report

The aim of this case study is to present a clinical approach to treatment of a mandibular intrabony cyst employing guided bone regeneration principles and protection of the mandibular nerve prior to implant placement. A treatment approach employing a combination of grafting materials and membranes was used to treat the cyst and protect the mandibular nerve prior to implant placement. Micro CT, as well as histology and histomorphometrics, was used to evaluate treatment outcomes. Histological inspection showed bone regeneration at the grafting site. Histomorphometric analysis of the biopsy core rendered a total bone percent area of 58.87% and 41.13% soft tissue. Out of the total bone percent area, 90.45% was revealed as vital bone and 9.55% was graft remnant. The grafted area is supporting an implant-supported prosthesis in full function.

Correction of bone and softtissue deformity of the single implant in the aesthetic zone: a case treated with alveolar ridge preservation, modified roll technique and a digitally coded healing abutment

The correction of soft tissue deformity and aesthetic rehabilitation of a single implant in the aesthetic zone with a combination of periodontal and prosthodontic approaches is described. Soft tissue deformity was corrected resulting in significant soft tissue volume increase and eliminated the need for prosthetic gingival replacement. A two stage implant placement protocol, ridge preservation and a soft tissue augmentation flap design preserved epithelium attachment to the connective tissues. Use of a digitally coded healing abutment preserved the newly established soft tissue volume, allowed impression making without implant component removal, and minimized trauma to the newly established soft tissue architecture.

Multifunctional materials for bone cancer treatment

The purpose of this review is to present the most recent findings in bone tissue engineering. Special attention is given to multifunctional materials based on collagen and collagen-hydroxyapatite composites used for skin and bone cancer treatments. The multi-functionality of these materials was obtained by adding to the base regenerative grafts proper components, such as ferrites (magnetite being the most important representative), cytostatics (cisplatin, carboplatin, vincristine, methotrexate, paclitaxel, doxorubicin), silver nanoparticles, antibiotics (anthracyclines, geldanamycin), and/or analgesics (ibuprofen, fentanyl). The suitability of complex systems for the intended applications was systematically analyzed. The developmental possibilities of multifunctional materials with regenerative and curative roles (antitumoral as well as pain management) in the field of skin and bone cancer treatment are discussed. It is worth mentioning that better materials are likely to be developed by combining conventional and unconventional experimental strategies.

A randomized, blinded, controlled clinical study of particulate anorganic bovine bone mineral and calcium phosphosilicate putty bone substitutes for socket preservation

PURPOSE

The purpose of this study was to compare the clinical efficacy of an anorganic bovine bone graft particulate to that of a calcium phosphosilicate putty alloplast for socket preservation.

MATERIALS AND METHODS

Thirty teeth were extracted from 24 patients. The sockets were debrided and received anorganic bovine bone mineral (BOV, n=12), calcium phosphosilicate putty (PUT, n=12), or no graft (CTRL, n=6). The sockets were assessed clinically and radiographically 5 months later. Eight sockets in the BOV group and nine in the PUT group received implants 5 to 6 months postgrafting. The maximum implant insertion torque (MIT) was measured as an index of primary implant stability. The data were analyzed with the Mann-Whitney test.

RESULTS

Both test groups had statistically significantly less reduction in mean ridge width (BOV: 1.39±0.57 mm; PUT: 1.26±0.41 mm) in comparison to the control group (2.53±0.59 mm). No statistically significant difference was identified between the test groups. MIT for PUT was ≤35 N/cm² (MIT grade 4) for seven of the nine implants. MIT values in the BOV group ranged from grade 1 (10 to 19 N/cm²) to grade 4, which was statistically significantly lower than for the PUT group. The overall implant success rate was 94.1% (16 of 17 implants were successful). No implants were lost in the PUT group; one implant failed in the BOV group.

CONCLUSION

Both tested bone substitutes can be recommended for preservation of alveolar ridge width following extraction. PUT might be more suitable for achieving primary stability for implants placed at 5 to 6 months postextraction.

Substituted hydroxyapatites with antibacterial properties

Reconstructive surgery is presently struggling with the problem of infections located within implantation biomaterials. Of course, the best antibacterial protection is antibiotic therapy. However, oral antibiotic therapy is sometimes ineffective, while administering an antibiotic at the location of infection is often associated with an unfavourable ratio of dosage efficiency and toxic effect. Thus, the present study aims to find a new factor which may improve antibacterial activity while also presenting low toxicity to the human cells. Such factors are usually implemented along with the implant itself and may be an integral part of it. Many recent studies have focused on inorganic factors, such as metal nanoparticles, salts, and metal oxides. The advantages of inorganic factors include the ease with which they can be combined with ceramic and polymeric biomaterials. The following review focuses on hydroxyapatites substituted with ions with antibacterial properties. It considers materials that have already been applied in regenerative medicine (e.g., hydroxyapatites with silver ions) and those that are only at the preliminary stage of research and which could potentially be used in implantology or dentistry. We present methods for the synthesis of modified apatites and the antibacterial mechanisms of various ions as well as their antibacterial efficiency.

Platelet-rich fibrin in the treatment of periodontal bone defects

BACKGROUND

Periodontitis is characterized by the formation of true pockets, bone loss and attachment loss. Various techniques have been attempted in the past to truly regenerate the lost periodontal structures, albeit with variable outcome. In this evolution, the technique being tried out widely is the use of platelet rich concentrates, namely platelet-rich fibrin (PRF).

CASE DESCRIPTION

In this report, we present a case of surgical treatment of osseous bone defects namely two walled crater and dehiscence treated in posterior teeth with autologously prepared platelet rich fibrin mixed with hydroxy apatite bone graft and PRF in the form of a membrane.

CONCLUSION

Our results showed clinical improvements in all the clinical parameters postoperatively namely the pocket depth reduction and gain in attachment level and hence, PRF can be used alone or in combination with the bone graft to yield successful clinical results in treating periodontal osseous defects.

CLINICAL SIGNIFICANCE

Platelet-rich fibrin is an effective alternative to platelet-rich plasma (PRP) in reconstructing bone defects.

A novel dental implant system with an internal port for endoscopic closed sinus augmentation: a feasibility study in pigs

PURPOSE

This study describes the use of an innovative dynamic implant valve approach (DIVA) for dental implant placement and sinus augmentation procedures.

MATERIALS AND METHODS

The DIVA implant system was tested in vitro for leakage and mechanical fatigue. A closed sinus elevation procedure with a gel-type bone substitute was performed using the DIVA implant in a swine model (n = 6). Implants were placed and evaluated radiographically and histologically.

RESULTS

Elevation of the maxillary sinus membrane and augmentation were performed in a simple, minimally invasive fashion. Histologic analyses demonstrated complete sealing of the DIVA implant and excellent osseointegration.

CONCLUSION

The DIVA can be used as a simplified viable option for dental implantation and augmentation procedures. Hermetic sealing of this implant system, which features an inner screw, renders it safe.

The combined use of rhBMP-2/ACS, autogenous bone graft, a bovine bone mineral biomaterial, platelet-rich plasma, and guided bone regeneration at nonsubmerged implant placement for supracrestal bone augmentation. A case report

This case report presents the clinical application and outcomes of the use of a combined approach to treat a patient with a severe alveolar defect. Recombinant human bone morphogenetic protein-2 in an absorbable collagen sponge carrier, along with autogenous bone graft, bovine bone mineral, platelet-rich plasma, and guided bone regeneration, were used simultaneous with nonsubmerged implant placement. At 1 year postsurgery, healthy peri-implant soft tissues and radiographically stable peri-implant crestal bone levels were observed along with locally increased radiographic bone density. In addition, a cone beam computed tomography (CBCT) scan demonstrated apparent supracrestal peri-implant bone augmentation with the appearance of normal alveolar ridge contours, including the facial bone wall.

Regenerative periodontal therapy: 30 years of lessons learned and unlearned

In this review, we reflect upon advances and hindrances encountered over the last three decades in the development of strategies for periodontal regeneration. In this soul-searching pursuit we focus on revisiting lessons learned that should guide us in the quest for the reconstruction of the lost periodontium. We also examine beliefs and traditions that should be unlearned so that we can continue to advance the field. This learned/unlearned body of knowledge is consolidated into core principles to help us to develop new therapeutic approaches to benefit our patients and ultimately our society.

CERAMENT treatment of fracture defects (CERTiFy): protocol for a prospective, multicenter, randomized study investigating the use of CERAMENT™ BONE VOID FILLER in tibial plateau fractures

BACKGROUND

Bone graft substitutes are widely used for reconstruction of posttraumatic bone defects. However, their clinical significance in comparison to autologous bone grafting, the gold-standard in reconstruction of larger bone defects, still remains under debate. This prospective, randomized, controlled clinical study investigates the differences in pain, quality of life, and cost of care in the treatment of tibia plateau fractures-associated bone defects using either autologous bone grafting or bioresorbable hydroxyapatite/calcium sulphate cement (CERAMENT™|BONE VOID FILLER (CBVF)).

METHODS/DESIGN

CERTiFy (CERament™ Treatment of Fracture defects) is a prospective, multicenter, controlled, randomized trial. We plan to enroll 136 patients with fresh traumatic depression fractures of the proximal tibia (types AO 41-B2 and AO 41-B3) in 13 participating centers in Germany. Patients will be randomized to receive either autologous iliac crest bone graft or CBVF after reduction and osteosynthesis of the fracture to reconstruct the subchondral bone defect and prevent the subsidence of the articular surface. The primary outcome is the SF-12 Physical Component Summary at week 26. The co-primary endpoint is the pain level 26 weeks after surgery measured by a visual analog scale. The SF-12 Mental Component Summary after 26 weeks and costs of care will serve as key secondary endpoints. The study is designed to show non-inferiority of the CBVF treatment to the autologous iliac crest bone graft with respect to the physical component of quality of life. The pain level at 26 weeks after surgery is expected to be lower in the CERAMENT bone void filler treatment group.

DISCUSSION

CERTiFy is the first randomized multicenter clinical trial designed to compare quality of life, pain, and cost of care in the use of the CBVF and the autologous iliac crest bone graft in the treatment of tibia plateau fractures. The results are expected to influence future treatment recommendations.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov: NCT01828905.

Bone infections and bone graft substitutes for local antibiotic therapy

Osteomyelitis is a bone infection by micro-organisms. Despite advances in antibiotics and operative techniques, osteomyelitis remains an orthopaedic challenge and expensive to treat. Antimicrobial therapy is adequate for the treatment of most cases of acute osteomyelitis of any type, provided that diagnosis is made early. The treatment of chronic osteomyelitis is operative followed by adjunctive antibiotic therapy. Apart from surgical debridement and systemic antibiotic treatment, local antibiotic treatment by using various antibiotic delivery vehicles is a preferred method by most surgeons. Antibiotic-loaded bone cement (polymethylmethacrylate, PMMA) is the most widely used material and represents the current standard as an antibiotic delivery vehicle in orthopaedic surgery. Despite that, there are some disadvantages or concerns about the use of antibiotic-loaded PMMA that have led to the use of bioabsorbable or biodegradable material. Although the number of clinical studies is small, it seems that antibiotic-loaded hydroxyapatite and calcium sulfate are safe methods for local antibiotic delivery. They deliver great amounts of antibiotics locally with serum concentrations in safe margins, they obliterate the dead space, and aid in bone repair, while there is no need for a second operation for their removal. The purpose of this article is to review the recent literature concerning osteomyelitis and local antibiotic treatment with special reference to bone graft substitutes as vehicles for local antibiotic delivery.

Restoration of jaw bone tissue defect using osteoplastic material

The aim of the study was to repair mandibular bone defect using BIO-OSS artificial bone implantation. The experiment was conducted on 30 white laboratory rats. Defect in the bone of lower jaw was created surgically. Animals were divided into 2 groups. 15 animals were allocated in control group. Another 15 animals were allocated in the BIO-OSS treatment group.

CONTROL GROUP

analysis revealed bone defect in 6-month after modeling of bone defect. There was no pronounced proliferation of connective tissue visible in the defect area. Treatment group: In the samples of treated group, BIO-OSS bone mass formed basophilic fiber-like structures. It was surrounded with the thin proliferative connective and granulation tissues.

CONCLUSIONS

proposed technique of bone defect reconstruction is an effective and sustainable method and can be recommended for wider use in clinical practice.

Implant placement in the aesthetic zone following an autogenous bone graft from an intraoral site: a case study

AIMS

In the front of the mouth, the treatment of such a bony defect carries the risk of a poor aesthetic outcome. High patient expectations, combined with the difficulty of recreating a large mass of viable bone in which a dental implant will be biomechanically stable is a real challenge. PURPOSE OF TREATMENT: The intention of this treatment was to replace the patient's chronically infected upper right incisor with a dental implant that was both biomechanically and aesthetically stable for the long term.

METHOD

Four months after extraction of the upper right central incisor, under local anaesthetic, a bone block was harvested from the right retromolar area of the patient's mandible and grafted into the defect. This was secured with a single bone screw. Small deficiencies between the block and the host site were filled in using bovine derived particulate bone (Bio Oss, Geistlich Biomaterials, Wolhuser, Germany). A resorbable porcine derived membrane (Bio-Gide, Geistlich Biomaterials, Wolhuser, Germany), held in position by two bone tacks (Frios, Friadent, Mannheim, Germany), was used to stabilse the graft. Following close clinical and radiographic monitoring of graft maturation, the bone screw was removed at three months and one week later the implant placed. A bone level impression was taken at surgery, and the implant left submerged for four months before exposure and abutment connection. After a further period of two months to facilitate soft tissue contouring the definitive crown was cemented.

CONCLUSION

The implant tooth has been in trouble free function for eighteen months. In that period, the marginal bone levels and gingival margin around the implant have remained stable and aesthetically satisfactory.

Adult mesenchymal stem cells and impaction grafting: a new clinical paradigm shift

The demographic challenges of an increasingly aging population emphasize the need for innovative approaches to skeletal reconstruction to augment and repair skeletal tissue lost as a consequence of implant loosening, trauma, degeneration or in situations involving revision surgery requiring bone stock. These clinical imperatives to augment skeletal tissue loss have brought mesenchymal stem cells to the fore in combination with the emerging discipline of tissue engineering. To date, impaction bone grafting for revision hip surgery is a recognized technique to reconstitute bone utilizing morselized allograft to provide a good mechanical scaffold, although with little osteoinductive biological potential. This review details laboratory and clinical examples of a paradigm shift in the application of mesenchymal stem cells with allograft to produce a living composite using the principles of tissue engineering. This step change creates a composite that offers a biological and mechanical advantage over the current gold standard of allograft alone. This translation of tissue engineering concepts into clinical practice offers enormous input into the field of bone regeneration and has implications for translation and future change in skeletal orthopedic practice in an increasingly aging population.

Dynamic implant valve approach for dental implant procedures

OBJECTIVE

To present the results of our current research involving the dynamic implant valve approach (DIVA) in cases with human patients.

METHODS

The new kind of implant was designed with an internal sealing screw that might serve for drug delivery system and possible endoscopic direct observation via its channel. The DIVA was used in cases when the implant insertion should be combined with the maxillary sinus floor lifting and/or bone augmentation procedure. A total of 63 patients (female n = 31, male n = 32, age range 33-67 years old, mean age 49 years old) were treated with DIVA and 218 new type implants were inserted.

RESULTS

Out of 218 inserted implants, 146 implants were inserted in the maxilla with bone level < 5 mm, and 72 implants were inserted in the maxilla with bone level > 5 mm. The number of implants per patients varied from one to eight. The failure consisted of seven implants (3.2%) in five patients. No correlation was found between failure cases and the bone density or quality. Follow up (4 to 18 months) showed that in 211 cases (96.8%), the implantation was totally successful both from objective clinical, imaging (cone beam computed tomography) and subjective patients' viewpoints.

CONCLUSION

The new dynamic implant valve approach simplified dental implantation procedure and postoperative treatment. The implant with an inner sealing screw could be considered for use in cases when elevation of the maxillary sinus membrane is needed, as well as in cases when bone augmentation procedures or future treatment might be suspected.

1-stage versus 2-stage lateral sinus lift procedures: 1-year post-loading results of a multicentre randomised controlled trial

PURPOSE

To compare the efficacy of 1-stage versus 2-stage lateral maxillary sinus lift procedures.

MATERIALS AND METHODS

Sixty partially edentulous patients requiring 1 to 3 implants and having 1 to 3 mm of residual bone height and at least 5 mm bone width below the maxillary sinus, as measured on CT scans were selected. They were randomised according to a parallel group study design into two equal arms to receive either a 1-stage lateral window sinus lift with simultaneous implant placement or a 2-stage procedure with implant placement delayed by 4 months, using a bone substitute in three different centres. Implants were submerged for 4 months, loaded with reinforced provisional prostheses, which were replaced, after 4 months, by definitive prostheses. Outcome measures, assessed by masked assessors, were: augmentation procedure failures; prosthesis failures and implant failures; complications; and marginal peri-implant bone level changes. Patients were followed up to 1 year after loading. Only data of implants placed in 1 to 3 mm of bone height were reported.

RESULTS

Two patients dropped out from the 1-stage group and none from the 2-stage group. No sinus lift procedure failed in the 1-stage group but one failed in the 2-stage group, the difference being not statistically significant (P = 1.00). Two prostheses failed or could not be placed in the planned time in the 1-stage group and one in the 2-stage group, the difference being not statistically significant (P = 0.51). Three implants failed in three patients of the 1-stage group, versus one implant in the 2-stage group, the difference being not statistically significant (P = 0.28). Two complications occurred in the 1-stage group and one in the 2-stage group, the difference being not statistically significant (P = 0.61). One year after loading, 1-stage treated patients lost an average of -1.01 mm (SD: 0.56) of peri-implant bone and 2-stage sites about -0.93 mm (SD: 0.40). There were no statistically significant differences in bone level change between groups 1 year after loading (-0.08 mm 95%CI: -0.33 to 0.18 P = 0.56).

CONCLUSION

No statistically significant differences were observed between implants placed according to 1- or 2-stage sinus lift procedures. However this study may suggest that in patients having residual bone height between 1 to 3 mm below the maxillary sinus, there might be a slightly higher risk for implant failures when performing a 1-stage lateral sinus lift procedure.

Short implants versus longer implants in vertically augmented posterior mandibles: a randomised controlled trial with 5-year after loading follow-up

OBJECTIVES

To evaluate whether 6.6-mm long implants could be a suitable alternative to longer implants placed in vertically augmented atrophic posterior mandibles.

MATERIALS AND METHODS

Sixty partially edentulous patients having 7 to 8 mm of residual crestal height and at least 5.5 mm thickness measured on CT scans above the mandibular canal were randomised according to a parallel group design. They were either to receive 1 to 3 submerged 6.6-mm long implants or 9.6 mm or longer implants (30 patients per group) placed in vertically augmented bone. Bone was augmented with interpositional anorganic bovine bone blocks covered by resorbable barriers. Grafts were left to heal for 5 months before implant placement. Four months after provisional acrylic prostheses were delivered, they were replaced, after 4 months, by definitive metal-ceramic prostheses. Outcome measures were: prosthesis and implant failures; complications; and radiographic peri-implant marginal bone level changes. All patients were followed up to 5 years after loading.

RESULTS

Five years after loading, 8 patients dropped out: 3 from the short implant group and 5 from the augmented group. The augmentation procedure failed in 2 patients and only 6.6-mm long implants could be inserted. There were no statistically significant differences for prosthesis and implant failures. Five prostheses failed in 4 patients of the short implant group versus 5 prostheses in 5 patients in the augmented group (Fishers exact test P = 1.0; difference in proportions = 0.07; 95% CI -0.29 to 0.43). Five short implants failed in 3 patients versus 3 long implants in 3 patients (Fishers exact test P = 1.00 difference in proportions = 0.00; 95% CI -0.43 to 0.43). There were statistically more complications in augmented patients (25 complications in 21 augmented patients versus 6 complications in 6 patients of the short implant group) (Fishers exact test P < 0.0001; difference in proportions = 0.60; 95% CI 0.38, 0.82). Both groups gradually lost peri-implant bone in a statistically significant way. Five years after loading, short implant group patients lost an average of 1.49 mm peri-implant bone compared with 2.34 mm in the augmented group. Short implants experienced statistically significantly less bone loss (0.82 mm, 95% CI 0.48; 1.16, P < 0.0001) than long implants.

CONCLUSIONS

When residual bone height over the mandibular canal is between 7 to 8 mm, 6.6 mm short implants could be an interesting alternative to vertical augmentation in posterior atrophic mandibles since the treatment is faster, cheaper and associated with less morbidity. Longer follow-ups may still be needed to confirm these results, however the medium-term prognosis (5 years after loading) of short implants is at least as good as those of longer implants placed vertically in augmented mandibles.

Three-year results from a randomised controlled trial comparing prostheses supported by 5-mm long implants or by longer implants in augmented bone in posterior atrophic edentulous jaws

PURPOSE

To evaluate whether 5-mm short dental implants could be an alternative to augmentation with anorganic bovine bone and placement of at least 10-mm long implants in posterior atrophic jaws.

MATERIALS AND METHODS

Fifteen patients with bilateral atrophic mandibles (5 mm to 7 mm bone height above the mandibular canal) and 15 patients with bilateral atrophic maxillae (4 mm to 6 mm bone height below the maxillary sinus), and bone thickness of at least 8 mm, were randomised according to a split-mouth design to receive one to three 5-mm short implants or at least 10-mm long implants in augmented bone. Mandibles were vertically augmented with interpositional bone blocks and maxillary sinuses with particulated bone via a lateral window. Implants were placed after 4 months, submerged and loaded, after another 4 months, with provisional prostheses. Four months later, definitive provisionally cemented prostheses were delivered. Outcome measures were: prosthesis and implant failures; any complication and peri-implant marginal bone level changes.

RESULTS

In five augmented mandibles, the planned 10-mm long implants could not be placed and shorter implants (7 mm and 8.5 mm) had to be used instead. Three years after loading, two patients, one treated in the mandible and one in the maxilla, dropped out. Three prostheses (1 mandibular and 2 maxillary) failed in the short implant group versus none in the long implant group. In mandibles, one long implant failed versus two short implants in 1 patient. In maxillae, one long implant failed versus three short implants in 2 patients. There were no statistically significant differences in the failures. Eight patients had 13 complications at short implants (1 patient accounted for 6 complications) and 11 patients had 13 complications at long implants. There were no statistically significant differences in complications (P = 0.63, difference = 0.10, 95% CI from -0.22 to 0.42). Three years after loading, patients with mandibular implants lost on average 1.44 mm at short implants and 1.63 mm at long implants of peri-implant marginal bone. This difference was not statistically significant (difference = 0.24 mm; 95% CI -0.01, 0.49 P = 0.059). In maxillae, patients lost on average 1.02 mm at short implants and 1.54 mm at long implants. This difference was statistically significant (difference = 0.41 mm; 95% CI 0.21, 0.60, P = 0.001).

CONCLUSIONS

Three years after loading, 5-mm short implants achieved similar results as longer implants in augmented bone. Short implants might be a preferable choice to vertical bone augmentation, especially in mandibles, since the treatment is faster and cheaper, however there are still insufficient data on the long-term prognosis of short implants.

Involvement of bone marrow stem cells in periodontal wound healing

OBJECTS

To test the hypothesis whether bone marrow stem cells (BMSCs) could migrate into the periodontium as the precursor available for the repair of tissue injury.

METHODS

A chimeric mouse model was established by transplanting BMSCs derived from red fluorescent protein mouse into irradiated BALB/c mice. Subsequently, a periodontal defect was created beside the maxillary first molar and filled with ceramic bovine bone. Finally, the chimeric mice were divided into three groups and were observed 3, 14 and 28 days later respectively. The involvement of BMSCs in periodontal defects was analysed using an in vivo imaging system and immunohistochemical staining of CD45, CD105 and CD31. Cell surface marker expression in injured tissue was also compared with that in normal tissue.

RESULTS

Increasing numbers of BMSCs migrated into the periodontal defect with time. The distribution was initially limited to ceramic bovine bone and then around blood vessels and near alveolar bone. Furthermore, expression of CD105 and CD31 was much higher in injured periodontal tissue than that in healthy periodontium, although CD45 was not expressed in either of these tissues.

CONCLUSION

BMSCs, but not haemopoietic stem cells, were involved in periodontal defect; they entered the periodontium probably via blood vessels.

The effectiveness of surgical management of oroantral communications: a systematic review of the literature

BACKGROUND

An oroantral communication (OAC) is a common complication in alveolar surgery that usually occurs as a result of the extraction of maxillary posterior teeth. To avoid further complications, several closure techniques are used; most of them need a flap elevation. Recently, simpler conservative flapless techniques for OAC closure have been described.

OBJECTIVES

To appraise the effectiveness of different techniques for closure of OACs also in comparison to nothing.

SEARCH METHODS

The following electronic databases were searched for randomised controlled trials regarding techniques for closure of OACs: PubMed; SciVerse Scopus; Latin American and Caribbean Health Sciences; The Scientific Electronic Library Online and The Cochrane Library (from January 1949 to August 2014). Unspecific algorithms were chosen in order to maximise search sensibility. Additional manual searching was performed in PubMed related citations, in five journals and in the references of the selected articles. There were no restrictions with regard to publication language.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing techniques for closing oroantral communications to nothing, or different techniques for closing oroantral communications reporting the success rate with at least two months follow-up.

DATA COLLECTION AND ANALYSIS

The screening of eligible studies, the assessment of methodological quality and data extraction were done by two independent reviewers working in duplicate.

RESULTS

The research individuated 1256 publications. After screening, only five articles were assessed for eligibility. Only two RCTs evaluating the effectiveness of techniques for OAC closure fulfilled the inclusion criteria of the present review. One trial including 30 patients assessed whether flapless techniques (resorbable root analogues and haemostatic gauze) could be as effective as the Rehrmann's buccal flap; all the patients were reported as successfully healed in the three intervention groups. Another RCT with 20 patients compared the effectiveness of the buccal fat pad flap (100% success rate) with a sandwich graft with hydroxyapatite crystals within collagen sheaths (90% success rate). The authors found no significant difference.

CONCLUSIONS

There are no RCTs evaluating whether an oroantral communication should be closed or not. There is weak evidence from two RCTs showing good results with five different techniques for closure of OACs (resorbable root analogues, haemostatic gauze, Rehrmann's buccal flap, buccal fat pad flap, sandwich graft with hydroxyapatite crystals). Until sufficiently high quality RCTs are conducted, elevating or not a flap for closure of OACs will be left to the personal choice of the surgeon.

Alveolar ridge augmentation with autogenous mental block harvested using ultrasonic bone surgery (USBS) and platelet rich plasma: a case report

Predictable reconstruction of alveolar ridge defects can be obtained by using autogenous bone block. Ultrasonic bone surgery (USBS) is a fast, precise, and simple technique for block graft harvesting. It allows for a clean surgical field with no risk of injury to surrounding neurovascular structures. This article describes a case of horizontal alveolar ridge defect augmented with mental bone block harvested using USBS. The defect was overcorrected using bovine derived xenograft and platelet rich plasma, which is an autologous source of growth factors that helps in early graft consolidation. Platelet poor plasma (PPP) membrane was used for graft containment. After six months, on exposure, it was observed that the block graft was integrated with the alveolar ridge, resulting in increased ridge width. This was confirmed on dentascan and 3D reconstruction images. Implants were placed and restored with satisfactory aesthetic and functional outcome.

Augmentation procedures using bone substitute materials or autogenous bone - a systematic review and meta-analysis

AIMS

Bone substitute materials (BSM) are described as a reasonable alternative to autologous bone (AB) to simplify the grafting procedure. In a systematic review and meta-analysis, the influence of BSM compared to AB on treatment success in augmentation procedures of the edentulous jaw was analysed.

MATERIAL AND METHODS

Literature analysis resulted in only two studies addressing reconstruction of the totally edentulous jaw using BSM. Therefore the literature analysis was extended to partially and totally edentulous jaws. The following augmentation procedures were analysed: maxillary sinus floor augmentation (MSFA) and vertical and/or lateral alveolar ridge augmentation; guided bone regeneration (minor and contained defects) were excluded. Meta-analysis was implemented using the literature from the years 2000 to early 2014 and only studies with a mean follow-up of at least 10 months were included.

RESULTS

After screening 843 abstracts from the electronic database, 52 studies in qualitative and 14 in quantitative synthesis were included. In studies examining MSFA, the mean implant survival rate was 98.6% ± 2.6 for BSM, 88.6 ± 4.1% for BSM mixed with AB and 97.4 ± 2.2% for AB alone. For MSFA, meta-analysis showed a trend towards a higher implant survival when using BSM compared to AB, however the difference was not statistically significant ([OR], 0.59; [CI], 0.33-1.03). No statistically significant difference in implant survival for MSFA between BSM mixed with AB and AB was seen ([OR], 0.84; [CI], 0.5-1.42). Concerning ridge augmentation, the mean implant survival rate was 97.4 ± 2.5% for BSM, 100 ± 0% for BSM mixed with AB and 98.6 ± 2.9% for AB alone. Metaanalysis revealed no statistically significant difference in implant survival for ridge augmentation using BSM or AB ([OR], 1.85; [CI], 0.38 to 8.94). For BSM mixed with AB versus AB alone, a meta-analysis was not possible due to missing data.

CONCLUSIONS

Within the limitation of the meta-analytical approach taken, implant survival seems to be independent of the biomaterial used in MSFA and alveolar ridge augmentation. Therefore, based on the current literature, there is no evidence that AB is superior to BSM. The conclusions are limited by the fact that influence of defect size, augmented volume and regenerative capacity of the defects is not well described in the respective literature.