Clinical and histologic comparison of two different composite grafts for sinus augmentation: a pilot clinical trial

Clinical and radiographic evaluation of the use of PRF, CGF, and autogenous bone in the treatment of periodontal intrabony defects: Treatment of periodontal defect by using autologous products

BACKGROUND

The purpose of this randomized clinical study was to clinically evaluate and compare the efficiencies of platelet-rich fibrin (PRF), concentrated growth factor (CGF) and autogenous bone graft (ABG) in the treatment of intrabony pockets and to assess the alveolar bone gain (AB gain) radiographically (panoramic and CBCT images).

METHODS

Eighty intrabony pockets were divided into four groups: ojnly open flap debridement (OFD), OFD+PRF, OFD+CGF and OFD+ABG; each group consisted of 20 defects. Plaque index (PI), gingival index (GI), probing depth (PD), clinical attachment level (CAL), and tooth mobility (TM) by using Periotest M device were evaluated. Radiographic images were also taken to evaluate the AB gain. PRF was produced using a protocol of 2,700 RPM for 12 min and the relative centrifugal force (RCF) was evaluated. CGF was prepared as follows: 2 min 2700 rpm, 4 min 2400 rpm, 4 min 2700 rpm, 3 min 3000 rpm.

RESULTS

The study results revealed a similar improvement in PI and GI values in all groups (p > 0.05). There was a statistically significant decrease in PD and CAL in favor of ABG group at day 180 in comparison with other groups (p = 0.001). There was also a statistically significant decrease in TM and alveolar bone height loss (ABHL), whereby the AB gain gradually increased among the groups with the best group being ABG, followed by CGF, PRF, and control groups, respectively (p = 0.001).

CONCLUSIONS

The study results support the treatment of periodontal intrabony pockets using OFD in combination with ABG, CGF, and PRF, as ABG showed the best results followed by CGF and PRF.

Treatment of Unfavorable Intrabony Defects with Autogenous Bone Graft in Combination with Leukocyte- and Platelet-Rich Fibrin or Collagen Membranes: A Non-Inferiority Study

Background and Objectives: Unfavorable intrabony defects (IBDs) are associated with the progression of periodontal disease and tooth loss. Growing scientific evidence has demonstrated the effectiveness of platelet concentrations in periodontal treatment. The aim of our study was to demonstrate the non-inferiority of an autogenous bone graft (ABG) associated with leukocyte- and platelet-rich fibrin (L-PRF) compared to ABG + Collagen Membrane in the treatment of IBDs. Material and Methods: Sixty-four patients with at least one IBD were randomly assigned to two groups: ABG+L-PRF and CM+ABG. Clinical and radiographic evaluations were performed at baseline and 12-month follow-up. Clinical attachment level (CAL), gingival recession (GR), probing pocket depth (PPD), and radiograph defect bone level (DBL) were compared between the two treatments. To evaluate the effectiveness of ABG+L-PRF, a non-inferiority margin of =1 mm (-1 mm for GR) was chosen; a second non-inferiority margin of =0.5 mm (-0.5 mm for GR) was set for clinical relevance. Results: At 12-month follow up, both treatments showed clinical and radiographic improvements. The 90% confidence intervals of the CM+ABG-L-PRF+ABG mean difference for CAL gain (-0.0564 mm [-0.316 to 0.203]), DBL gain (-0.433 mm [-0.721 to -0.145]), and PPD reduction (0.232 mm [0.015 to 0.449]) were below the 0.5 mm non-inferiority margin; the GR increase (0.255 mm [0.0645 to 0.445]) stayed above the -0.5 mm. Conclusions: the L-PRF+ABG treatment of unfavorable IBDs is non-inferior with respect to the CM+ABG therapy for CAL gain, but with a lower GR, a slightly higher PPD, and DBL gain.

Treatment alternatives for the rehabilitation of the posterior edentulous maxilla

Rehabilitation of the edentulous maxilla with implant-supported fixed dental prostheses can represent a significant clinical challenge due to limited bone availability and surgical access, among other factors. This review addresses several treatment options to replace missing teeth in posterior maxillary segments, namely the placement of standard implants in conjunction with maxillary sinus floor augmentation, short implants, tilted implants, and distal cantilever extensions. Pertinent technical information and a concise summary of relevant evidence on the reported outcomes of these different therapeutic approaches are presented, along with a set of clinical guidelines to facilitate decision-making processes and optimize the outcomes of therapy.

Palatal bone block: A predictable bone augmentation technique for restricted maxillary defect

Bone grafting for implant dentistry depends on bone quality, quantity, and biological principles for good outcome. Autogenous bone as donor remains the gold standard among all the available materials. However, it carries unpredictable morbidity and need for different surgical sites. In our report, we describe a simplified approach in bone augmentation for restricted maxillary atrophic defect within the same surgical site as a harvesting site. The method can be an alternative for different intraoral surgical harvesting sites. The patient's left maxillary central incisor before treatment had a large bony defect which was reconstructed though single site approach of augmentation. The implant-supported restoration with healthy periodontium around even after 2 years of review looks promising. The approach can be an alternative for different intraoral surgical sites.

Cytocompatibility and Osteoinductive Properties of Collagen-Fibronectin Hydrogel Impregnated with siRNA Targeting Glycogen Synthase Kinase 3β: In Vitro Study

In this study, we developed an osteoplastic material based on collagen-fibronectin hydrogel impregnated with siRNA molecules targeting glycogen synthase kinase 3β (GSK3β), which inhibits the osteogenic differentiation of mesenchymal stem cells. The hydrogel impregnated with polyplexes containing siRNA GSK3β and polyethylenimine has been shown to have no cytotoxic effect: there was no statistically significant change in the cell's viability after 7 days of incubation in its presence compared to the control group. On days 2 and 7, an increase in the level of expression of markers of osteogenic differentiation was observed, which confirms the osteoinductive qualities of the material. It has been demonstrated that the hydrogel maintains cell adhesion. Our results obtained in vitro indicate cytocompatibility and osteoinductive properties of collagen-fibronectin hydrogel impregnated with siRNA GSK3β molecules.

Bicalcium Phosphate as an Asset in Regenerative Therapy

After a loss of a tooth, alveolar bone resorption is immutable, leaving the area devoid of sufficient bone quality and mass for a successful and satisfactory implant or any other dental treatment. To treat this problem of irreversible bone loss, bone grafting is the primary solution and a well-accepted technique. The use of bone grafting procedures has increased in recent years. This review is about the various bone grafting techniques and best-situated material available currently along with their trump cards and limitations. In the thorough discussion regarding bone grafting materials and their substitutes, one alloplastic material has shown unbeaten and the most satisfactory properties than any other material, "bicalcium phosphate" (BCP). BCP is a mixture of hydroxyapatite (HA) and beta-tricalcium phosphate (B-TCP) usually obtained through sintering calcium-deficient apatite (CDA) at or above 700°C or by other methods such as hydrolysis or precipitation. The review also shows comparative studies done to understand the effect, most adequate balance, and impact of ratios of HA/B-TCP on the properties, structure, and success rate of this material. The objective of the review is to enlighten the principal characteristic of the most likely used bone graft material presently, i.e., BCP. The most impeccable characteristic of BCP is its capability to osteointegrate, which results in a superior interface. This interface depicts a dynamic process that includes physicochemical reactions, crystal-protein interactions, cell and tissue colonization, and bone remodeling. BCP has certain essential properties that could be put forth as its advantage over any other substitute. These properties include bioactivity, osteointegration, osteoinduction, osteogenesis, and biodegradation, which are mostly governed by modifying the HA/B-TCP ratio. Other applications of BCP are feasible, such as in drug administration and scaffolds for tissue engineering.

Bone Grafts in Dental Medicine: An Overview of Autografts, Allografts and Synthetic Materials

This review provides an overview of various materials used in dentistry and oral and maxillofacial surgeries to replace or repair bone defects. The choice of material depends on factors such as tissue viability, size, shape, and defect volume. While small bone defects can regenerate naturally, extensive defects or loss or pathological fractures require surgical intervention and the use of substitute bones. Autologous bone, taken from the patient's own body, is the gold standard for bone grafting but has drawbacks such as uncertain prognosis, surgery at the donor site, and limited availability. Other alternatives for medium and small-sized defects include allografts (from human donors), xenografts (from animals), and synthetic materials with osteoconductive properties. Allografts are carefully selected and processed human bone materials, while xenografts are derived from animals and possess similar chemical composition to human bone. Synthetic materials such as ceramics and bioactive glasses are used for small defects but may lack osteoinductivity and moldability. Calcium-phosphate-based ceramics, particularly hydroxyapatite, are extensively studied and commonly used due to their compositional similarity to natural bone. Additional components, such as growth factors, autogenous bone, and therapeutic elements, can be incorporated into synthetic or xenogeneic scaffolds to enhance their osteogenic properties. This review aims to provide a comprehensive analysis of grafting materials in dentistry, discussing their properties, advantages, and disadvantages. It also highlights the challenges of analyzing in vivo and clinical studies to select the most suitable option for specific situations.

Autogenous Chin Block Grafts for Implant-Supported Rehabilitation: A 20-Year Follow-Up Case Series

The aim of the present study was to analyze the survival and success rates of dental implants placed in atrophic alveolar ridges reconstructed with mandibular symphysis autogenous onlay bone grafts, with a 20-year follow-up. A sample of five patients referred to the authors' department between 2000 and 2001 seeking for an implant-supported fixed rehabilitation. Patients were treated by means of autogenous bone blocks grafted from the mandibular symphysis and covered with bone substitutes (DBB) and a resorbable membrane. Then delayed implants were placed and finally prosthetic restoration was performed. In total, 10 implants placed in 5 patients were evaluated with a follow-up of 20 years. Both implant survival and success rate were 100%. The mean marginal bone loss was 0.32  [[EQUATION]]  0.39 mm (range 0-1.3 mm). Considering the conditions of peri-implant hard and soft tissues, the diagnosis of peri-implant health was made for all the implants included. According to this study, implants placed in alveolar ridges augmented by means of autogenous chin bone grafts showed long-term survival and high success rates. A correct management of peri-implant soft tissues and an accurate prosthetic rehabilitation are also fundamental to obtain the durable success of the treatment.

The allogeneic shell technique for alveolar ridge augmentation: a multicenter case series and experiences of more than 300 cases

PURPOSE

Allogeneic cortical bone plates (CP) might be used for alveolar ridge augmentation as an alternative to autogenous grafts (AG) and bone substitutes (BS). We report about a multicenter case series and our experiences of more than 300 cases using CP and the shell technique for reconstruction of the alveolar process to illustrate surgical key steps, variations, and complication management.

METHODS

Different types of alveolar ridge defects were augmented using the shell technique via CP. The space between the CP and the alveolar bone was filled with either autogenous or allogeneic granules (AUG, ALG) or a mixture of both. Implants were placed after 4-6 months. Microscopic and histological assessments were performed. In addition, space filling using AUG, ALG and bovine BS was discussed.

RESULTS

Scanning electron microscopy demonstrated the compact cortical structure of CP and the porous structure of ALG allowing micro-vessel ingrowth and bone remodeling. Histological assessment demonstrated sufficient bone remodeling and graft resorption after 4-6 months. In total, 372 CP cases and 656 implants were included to data analysis. The mean follow-up period was about 3.5 years. Four implants failed, while all implant failures were caused by peri-implantitis. Next, 30 CP complications were seen, while in 26 CP complications implant placement was possible. CP rehydration, stable positioning by adjusting screws, smoothing of sharp edges, and a tension-free wound closure were identified as relevant success factors. Space filling using ALG and a mixture of AUG/ALG resulted in sufficient bone remodeling, graft resorption and stability of the augmented bone.

CONCLUSIONS

CP and the shell technique is appropriate for alveolar ridge augmentation with adequate bone remodeling and low complication rates. Allografts can prevent donor site morbidity and therefore may decrease discomfort for the patient.

Applications of maxillary tuberosity block autograft

OBJECTIVE

Autogenous bone grafts are considered the gold standard due to their compatibility and osteogenic potential to induce new bone formation through osteogenesis, osteoinduction, and osteoconduction. The aim of this paper was to describe clinical applications of the maxillary tuberosity block autograft in small and moderate localized defects of the alveolar process around implants and teeth.

CLINICAL CONSIDERATIONS

Maxillary tuberosity is often used as a particulate graft for augmentation of deficient alveolar ridge or maxillary sinus prior to or simultaneously with implant insertion, but not as a bone block graft. The maxillary tuberosity block autograft may also provide a valuable bone source for challenging situations such as immediate implant placement into types II and III extraction sockets, treatment of horizontal and vertical bone defects with simultaneous implantation, reconstruction of circumferential defects around implants, and preservation of alveolar ridge.

CONCLUSIONS

The advantages of the maxillary tuberosity include intraoral corticocancellous autogenous graft with fewer intraoperative difficulties, no need for donor site restoration, less morbidity, and an excellent correction of localized alveolar ridge defects.

CLINICAL SIGNIFICANCE

Within the limitations of the presented case reports, the use of maxillary tuberosity block autograft has shown to be successful in alveolar ridges augmentation that lack both width and height.

Comparison of the 3D-Microstructure Between Alveolar and Iliac Bone for Enhanced Bioinspired Bone Graft Substitutes

In oral- and maxillofacial bone augmentation surgery, non-vascularized grafts from the iliac crest demonstrate better clinical performance than alveolar bone grafts. The underlying mechanisms are not fully understood but are essential for the enhancement of bone regeneration scaffolds. Synchrotron Radiation µ-CT at a pixel size of 2.3 μm was used to characterize the gross morphology and the vascular and osteocyte lacuna porosity of patient-matched iliac crest/alveolar bone samples. The results suggest a difference in the spatial distribution of the vascular pore system. Fluid simulations reveal the permeability tensor to be more homogeneous in the iliac crest, indicating a more unidirectional fluid flow in alveolar bone. The average distance between bone mineral and the closest vessel pore boundary was found to be higher in alveolar bone. At the same time, osteocyte lacunae density is higher in alveolar bone, potentially compensating for the longer average distance between the bone mineral and vessel pores. The present study comprehensively quantified and compared the 3D microarchitecture of intraindividual human alveolar and iliac bone. The identified difference in pore network architecture may allow a bone graft from the iliac crest to exhibit higher regeneration potential due to an increased capacity to connect with the surrounding pore network of the residual bone. The results may contribute to understanding the difference in clinical performance when used as bone grafts and are essential for optimization of future scaffold materials.

Implant survival after graftless sinus floor augmentation in highly atrophic maxillae: a randomized controlled trial in a split mouth study

PURPOSE

The success rate of dental implants after graftless sinus augmentation versus conventional sinus augmentation surgery in atrophic maxillae in edentulous patients was investigated.

METHODS

This randomized study was performed in ten edentulous patients with marked maxillary atrophy. On the graftless side, the sinus membrane was lifted by a resorbable membrane. The control side was augmented with a mixture of autografts and xenografts. Implant placement followed 6 months postoperatively. Outcomes were implant survival, success of prosthetic rehabilitation and stability of vertical bone gain.

RESULTS

Ten patients were included. Postoperative radiology showed sufficient bone gain on both maxillary sides. Follow-up varied from 57 to 88 months. The conventional side showed significant (p = 0.041) more bone gain than the experimental side (respectively, 9.69 mm and 6.20 mm). A total of 59 implants were placed: 30 after conventional, 29 after graftless augmentation. One implant was lost on the conventional side and four on the experimental side. The implant survival was significantly higher on the conventional side (96.7% vs. 86.2%, p < 0.001, RR = 4.14). Prosthetic restoration was functionally successful in all cases.

CONCLUSION

Bone gain and implant survival were significantly lower in the non-grafted side versus the grafted side. Prosthetic rehabilitation was possible in all ten patients. The non-grafted technique may have some potential for clinical use, although it showed poorer results. Trial registration The Netherlands Trialregister. NTR NL3541 (NTR3696). Registered 20 January 2013, https://www.trialregister.nl/trial/3541 .

Comparison of Success Rate of Dental Implants Placed in Autogenous Bone Graft Regenerated Areas and Pristine Bone

Autogenous bone grafting still has been considered as the "gold standard" and wildly used in the case of alveolar bone reconstruction. The aim of the present study is to evaluate the success rate of implants placed in autogenous block augmented ridges and implants placed in pristine bone (PB). This study included 113 patients. Fifty-three patients were treated with autogenous block grafts and particulate bone, after 6 months of healing implant placements were performed in autogenous bone augmented (ABA) areas. In 60 patients implant placement was performed, with no need for grafting and implants were placed into the PB. Follow-up data (pain, mobility, exudation from peri-implant space, success rate, marginal bone resorption) were collected after 5 years of prosthetic loading. The cumulative implant success rate at the 5-year examination was 92.45% for the ABA group and 85% for PB group. There were 3 failed implants in the ABA group and 3 in PB group. Average marginal bone loss was 1.47 mm on ABA group and 1.58 mm on PB group. No statistically significant differences for pain, exudation from peri-implant space, implant mobility, implant success, peri-implant bone loss parameters, and patient satisfaction level were found between groups. The obtained data demonstrated that the success rate of implants placed in regenerated areas are very similar to the success rate of implants those placed in PB.

Ibandronate Reduces the Surface Bone Resorption of Mandibular Bone Grafts: A Randomized Trial With Internal Controls

Autologous bone grafts are considered the gold standard for reconstruction of the edentulous alveolar ridges. However, this procedure is associated with unpredictable bone loss caused by physiological bone resorption. Bisphosphonates are antiresorptive drugs that act specifically on osteoclasts, thereby maintaining bone density, volume, and strength. It was hypothesized that the resorption of bone grafts treated with an ibandronate solution would be less advanced than bone grafts treated with saline. Ten patients who underwent bilateral sagittal split osteotomy were included in a randomized double‐blind trial with internal controls. Each patient received a bone graft treated with a solution of ibandronate on one side and a graft treated with saline (controls) contralaterally. Radiographs for the measurement of bone volume were obtained at 2 weeks and at 6 months after surgery. The primary endpoint was the difference in the change of bone volume between the control and the ibandronate bone grafts 6 months after surgery. All of the bone grafts healed without complications. One patient was excluded because of reoperation. In eight of the nine patients, the ibandronate bone grafts showed an increase in bone volume compared with baseline, with an average gain of 126 mm³ (40% more than baseline) with a range of +27 to +218 mm³. Only one ibandronate‐treated graft had a decrease in bone volume (8%). In the controls, an average bone volume loss of −146 mm³ (58% of baseline) with a range of −29 to −301 mm³ was seen. In the maxillofacial field, the reconstructions of atrophic alveolar ridges, especially in the esthetical zones, are challenging. These results show that bone grafts locally treated with ibandronate solution increases the remaining bone volume. This might lead to new possibilities for the maxillofacial surgeons in the preservation of bone graft volumes and for dental implant installations. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

Relative performance of various biomaterials used for maxillary sinus augmentation: A Bayesian network meta-analysis

Objectives

To assess the histomorphometric outcomes obtained in randomized clinical trials (RCTs) with different biomaterials used for maxillary sinus augmentation (MSA).

Materials and Methods

A search of the existing medical literature until October 1, 2019, was performed. Inclusion criteria were (a) RCTs assessing a two‐stage MSA from the lateral approach using autologous bone or biomaterials for grafting and (b) reported histomorphometric outcomes based on crestal bone core biopsy samples. The Bayesian method was used to perform pairwise meta‐analyses and network meta‐analysis (NMA). The primary outcome, the new bone percentage (NB %), was calculated as mean differences with 95% credible intervals. The interventions were ranked by their posterior probability by calculating the surface under the cumulative ranking curve values.

Results

Thirty‐four RCTs (842 MSAs) were included in the analysis with a normal healing period (5–8 months). All comparisons were presented in a league table. On the basis of the ranking probability, the most effective bone grafting material for NB% was bovine xenograft + bone marrow concentrate (BMC) (81%), followed by bovine xenograft + platelet‐rich plasma (PRP) (77%), bioactive glass ceramic + autologous bone 1:1 (70%), nanocrystalline hydroxyapatite in silica gel (70%), and bioactive glass ceramic (70%). Autologous bone graft alone took the twelfth position with 57%.

Conclusion

Within the limitations of the present NMA, the analysis did not confirm autologous bone alone as the gold standard for MSA and showed superiority of composite grafts such as bovine xenograft + BMC after 5–8 months of healing.

A novel digital approach for fixed full-mouth implant-supported rehabilitations: A case report

Successful rehabilitation of a patient’s entire dentition with implant-supported fixed prostheses requires restoration of function, esthetics and comfort. To achieve this goal, the clinician and laboratory technician must work in concert with one another to navigate the multiple steps from the patient’s initial evaluation to delivery of the final prostheses. Key to this is the ability of the clinician to provide the technician with detailed information regarding the patient’s extra- and intraoral characteristics in a manner that can be easily and accurately transferred to the lab bench where it then serves as the foundation for reconstruction of the dentition. In recent years, the impressive evolution of digital technology in dentistry has dramatically facilitated this complex process. The aim of this case report is to illustrate how digital profiles of a patient’s facial and intraoral features can be merged with one another and used to generate artificial teeth and gingival tissue of a full mouth implant supported rehabilitation via computer-aided design and computer-aided manufacturing (CAD/CAM) technology to successfully rehabilitate a patient that initially presented with a terminal dentition.

Key words:Facial scan, Zirconia, Implant-supported rehabilitation, Implant-supported prosthesis, Fixed prosthesis, Oral rehabilitation.

Autogenous Chin Block Grafts in the Aesthetic Zone: A 20-Year Follow-Up Case Report

The successful use of osseointegrated implants in the treatment of partial or complete edentulism requires a sufficient bone support. Whenever rehabilitation in atrophic edentulous areas is needed, bone augmentation procedures are recommended. The aim is to provide adequate amount of supporting bone to achieve a prosthetically guided implant placement. This in turn leads to functional and aesthetic improvements that can be maintained on the long term. Bone grafting of the atrophic site can be performed either prior to implant placement or at the time of implantation. Irrespective of the timing, bone augmentation by means of autogenous bone grafts is a reliable technique, as confirmed by several studies. On the other hand, long-term evidence on the use of autogenous chin block grafts in preprosthetic implant surgery is still scarce. Thus, the purpose of the present case is to report the 20-year clinical and radiological outcome of autogenous chin block grafts used to augment a bilateral defect due to agenesis of the upper lateral incisors for implant placement purposes.

Ridge preservation following tooth extraction using bovine xenograft compared with porcine xenograft: A randomized controlled clinical trial

BACKGROUND

The primary purpose of this study was to histologically determine if there is a significant difference in new bone formation, residual graft material, and connective tissue/other when ridge preservation is accomplished using a bovine versus a porcine xenograft.

METHODS

Forty-four patients needing a single rooted tooth extraction and ridge preservation in preparation for dental implant placement were recruited in the study. After minimally traumatic tooth extraction, alveolar ridge dimensions were measured using a custom-fabricated acrylic stent. Patients were then randomized 1:1 to receive ridge preservation using either bovine or porcine xenograft material. A trimmed dense polytetrafluoroethylene (d-PTFE) membrane was overlaid on the graft material, the mucoperiosteal flaps were replaced, and the surgical site was sutured. After 18 to 20 weeks of wound healing, sites were surgically re-entered, ridge dimensions were again measured using the previously fabricated acrylic stents and a bone core sample of the grafted site was harvested for histomorphometric analysis.

RESULTS

Thirty eight of the 44 enrolled patients completed the study, 17 from the bovine group and 21 from the porcine group. Histologically, there were no statistically significant differences between the groups for mean percentage of vital bone formation (bovine = 36.21%, porcine = 31.27%, P = 0.49), residual graft material (bovine = 20.47%, porcine = 19.52%, P = 0.82) and connective tissue/other (bovine = 43.32%, porcine = 49.21%, P = 0.19). For secondary outcomes, there were no significant differences between the groups for mean change in buccal ridge height, lingual ridge height, and ridge width. However, a higher number of patients in the porcine group had additional grafting at the time of implant placement, either because of thin buccal plate or failure of implant stability.

CONCLUSION

The findings suggest that ridge preservation with porcine xenograft results in comparable histomorphometric outcomes and dimensional stability with bovine xenograft.

Trauma induced tissue survival in vitro with a muscle-biomaterial based osteogenic organoid system: a proof of concept study

BACKGROUND

The translation from animal research into the clinical environment remains problematic, as animal systems do not adequately replicate the human in vivo environment. Bioreactors have emerged as a good alternative that can reproduce part of the human in vivo processes at an in vitro level. However, in vitro bone formation platforms primarily utilize stem cells only, with tissue based in vitro systems remaining poorly investigated. As such, the present pilot study explored the tissue behavior and cell survival capability within a new in vitro skeletal muscle tissue-based biomaterial organoid bioreactor system to maximize future bone tissue engineering prospects.

RESULTS

Three dimensional printed β-tricalcium phosphate/hydroxyapatite devices were either wrapped in a sheet of rat muscle tissue or first implanted in a heterotopic muscle pouch that was then excised and cultured in vitro for up to 30 days. Devices wrapped in muscle tissue showed cell death by day 15. Contrarily, devices in muscle pouches showed angiogenic and limited osteogenic gene expression tendencies with consistent TGF-ß₁, COL4A1, VEGF-A, RUNX-2, and BMP-2 up-regulation, respectively. Histologically, muscle tissue degradation and fibrin release was seen being absorbed by devices acting possibly as a support for new tissue formation in the bioceramic scaffold that supports progenitor stem cell osteogenic differentiation.

CONCLUSIONS

These results therefore demonstrate that the skeletal muscle pouch-based biomaterial culturing system can support tissue survival over a prolonged culture period and represents a novel organoid tissue model that with further adjustments could generate bone tissue for direct clinical transplantations.

Does periodontally accelerated osteogenic orthodontics improve orthodontic treatment outcome? A systematic review and meta-analysis

BACKGROUND

Periodontally accelerated osteogenic orthodontics (PAOO) can be used to improve periodontal conditions and accelerate tooth movement.

OBJECTIVE

The aim of this systematic review and meta-analysis was to compare periodontal outcome and treatment duration of patients undergoing PAOO to accelerate orthodontic treatment.

SEARCH METHOD

An electronic search was performed in four electronic databases including Pubmed, EBSCO Cochrane library, CINAHL Complete for randomized clinical trials till November 2017. A hand search was performed on clinicaltrials.gov and Google scholar.

SELECTION CRITERIA

Randomized controlled trials reporting periodontal outcomes and treatment duration of PAOO in adult patients by evaluating treatment duration, root resorption, bone density and pocket depths were included.

DATA COLLECTION AND ANALYSIS

Two authors conducted searches, data extraction and bias assessment with conflict resolution with a third author. Cochrane's tool for risk of bias assessment was used for evaluation. A manual search was conducted for additional studies. A quantitative synthesis of the pooled results was conducted.

RESULTS

Five studies were included in the qualitative synthesis and two in the quantitative synthesis. A total of 56 patients underwent the PAOO technique; the effects of this therapy were compared with 21 patients who underwent corticotomy, 9 underwent non-extraction comprehensive orthodontic treatment and 15 underwent fixed mechanotherapy with extractions of first premolars. A random effect model was used for pocket depths and showed a non-significant difference between bioactive glass augmented corticotomy and corticotomy alone (weighted mean difference, -0.03; 95% CI, -0.16, 0.09). Bone density elucidated a non-significant difference between bioactive glass augmented corticotomy and corticotomy alone (weighted mean difference, 27.69; 95% CI, -2.29, 57.67). Fixed effect model was used for root length which revealed a non-significant difference between bioactive glass augmented corticotomy and corticotomy alone (weighted mean difference, 0.01; 95% CI, -0.00, 0.02).

CONCLUSIONS

Studies showed significant improvements in periodontal health. Treatment duration was reduced in patients who underwent PAOO. Root resorption was not sufficiently evaluated by current literature.

Sinus floor elevation using particulate PLGA-coated biphasic calcium phosphate bone graft substitutes: A prospective histological and radiological study

BACKGROUND

Poly (lactic-co-glycolic acid) (PLGA) is widely used for the development of delivery systems for drugs and therapeutic biomolecules in tissue engineering applications. Particles of biphasic calcium phosphate can be covered by PLGA to change their manipulating characteristics.

PURPOSE

Aim of this study was to investigate the radiological and histomorphometric results of the use of PLGA-coated biphasic calcium phosphate granules in sinus floor elevation and to analyze the underlying molecular processes by immunohistochemical staining.

MATERIALS AND METHODS

A randomized clinical study was designed to include patients in need of sinus floor elevation. Patients were assigned to receive either PLGA-coated biphasic calcium phosphate particles (group I) or the equivalent but noncoated particles (group II). Cone beam computed tomography (CBCT) scans were performed before and 6 months after the procedure to assess the bone height gain. At the time of implant placement, bone core biopsies were obtained at the site of implant placement. Histological sections were subjected to histomorphometric and immunohistochemical evaluation of differentiation markers (Musashi-1 [MSI1]).

RESULTS

No statistically significant differences were observed between groups for the radiologic parameters. No differences were observed histologically or histomorphometrically. However, PLGA-coated particles (group I) were more colonized by MSI1-positive osteoblast precursors (P = 0.0001, chi-squared test) and were penetrated by more CD34-positive vascular structures (P = 0.001, chi-squared test) than noncoated particles (group II).

CONCLUSIONS

PLGA-coated particles are associated with more MSI11-positive cells and more extensive microvascularization than noncoated particles.

Encapsulated melatonin in polycaprolactone (PCL) microparticles as a promising graft material

Electrospraying assures many advantages with taking less time and costing less relatively to the other conventional particle production methods. In this research, we investigated the encapsulation of melatonin (MEL) hormone in polycaprolactone (PCL) microparticles by using electrospraying method. Morphology analysis of the produced particles completed with Scanning Electron Microscopy (SEM). SEM images demonstrated that micro-particles of 3 wt% PCL solution has the most suitable particle diameter size (2.3 ± 0.64 μm) for melatonin encapsulation. According to the characterization of the particles, electrospraying parameters like optimal collecting distance, the flow rate of the solution and voltage of the system detected as 8 cm, 0.5 ml/h, and 10 kV respectively. For determining the chemical bonds of scaffold Fourier-Transform Infrared Spectroscopy (FTIR) were used and FTIR results showed that melatonin successfully loaded into PCL micro-particles. Drug release kinetics of the melatonin loaded particles indicated that melatonin released with a burst at the beginning and release behavior became sustainable over a period of 8 h with the encapsulation efficiency of about 73%. In addition, both in-vitro and in-vivo studies of the graft materials also completed. Primary human osteoblasts (HOB) cells and female Sprague Dawley rats were used in in-vitro and in-vivo studies. Test results demonstrate cell population, and bone volume of the rats grafted with composites has remarkably increased, this caused remodelling in bone structure. Overall, these findings indicate that encapsulation of melatonin in the PCL particles with electrospray method is optimum for new synthetic graft material.

Bone Formed After Maxillary Sinus Floor Augmentation by Bone Autografting With Hydroxyapatite and Low-Level Laser Therapy: A Randomized Controlled Trial With Histomorphometrical and Immunohistochemical Analyses

PURPOSE

The aim of this study was to evaluate the bone formed after maxillary sinus floor augmentation (MSFA) by bone autografting combined with hydroxyapatite (HA) that had been either treated with low-level laser therapy (LLLT) or not.

MATERIALS AND METHODS

Twelve biopsies were obtained from patients 6 months after MSFA using a combination of 50% of autogenous bone (AB) and 50% of HA (AB/HA group, n = 6) followed by LLLT (AB/HA-LLLT group, n = 6). The laser used in this study was gallium-aluminium-arsenide laser with a wavelength of 830 nm (40 mW; 5.32 J/point; 0.57 W/cm). Samples obtained were subjected to histological, histometric, and immunohistochemical analysis for detection of tartrate-resistant acid phosphatase and runt-related transcription factor 2. The data were submitted to statistical analysis (Shapiro-Wilk and Student t tests; α = 5%).

RESULTS

Statistical analysis revealed no significant difference in vital bone presence and immunohistochemical analysis between the groups. There was no reduction in bone marrow or fibrous tissue in the AB/HA group and AB/HA-LLLT group. There was a decrease in the amount of remaining biomaterial between the groups (P = 0.0081).

CONCLUSION

LLLT did not increase the formation of new bone; instead, it accelerated the bone remodeling process.

Purification processes of xenogeneic bone substitutes and their impact on tissue reactions and regeneration

Xenogeneic bone substitute materials are widely used in oral implantology. Prior to their clinical use, purification of the former bone tissue has to be conducted to ensure the removal of immunogenic components and pathogens. Different physicochemical methods are applied for purification of the donor tissue, and temperature treatment is one of these methods. Differences in these methods and especially the application of different temperatures for purification may lead to different material characteristics, which may influence the tissue reactions to these materials and the related (bone) healing process. However, little is known about the different material characteristics and their influences on the healing process. Thus, the aim of this mini-review is to summarize the preparation processes and the related material characteristics, safety aspects, tissue reactions, resorbability and preclinical and clinical data of two widely used xenogeneic bone substitutes that mainly differ in the temperature treatment: sintered (cerabone^®) and non-sintered (Bio-Oss^®) bovine-bone materials. Based on the summarized data from the literature, a connection between the material-induced tissue reactions and the consequences for the healing processes are presented with the aim of translation into their clinical application.

Aggregation Behavior of Nano-Silica in Polyvinyl Alcohol/Polyacrylamide Hydrogels Based on Dissipative Particle Dynamics

Due to the aggregation behavior of nano-silica in aqueous solution, the use of nano-silica without surface modification for synthesizing hydrogels is still a challenging task. This paper presents our study on the use of dissipative particle dynamics simulations to discover the aggregation behavior of nano-silica in polyvinyl alcohol (PVA)/polyacrylamide (PAM) blended hydrogels. By simulations, we aimed at investigating the effects of such factors as nano-silica content, polymer component ratio, temperature and shear rate on the aggregation behavior of nano-silica in terms of the mesoscopic morphologies and the relative concentration distribution functions. Our results reveal that the dispersion of nano-silica is seen if the nano-silica content is increased to 1.5%, and the aggregation of nano-silica becomes noticeable in blended hydrogels with an increase in the nano-silica content. This finding agrees well with the experimental results obtained by means of scanning electron microscopy. Furthermore, it is also found that the dispersion of nano-silica becomes more uniform with an increase in PAM content, temperature and shear rate. These findings greatly enrich our understanding of the aggregation behavior of nano-silica in PVA/PAM blended hydrogels.

Autogenous bone grafts in oral implantology-is it still a "gold standard"? A consecutive review of 279 patients with 456 clinical procedures

Background

This study assessed the clinical outcomes of graft success rate and early implant survival rate after preprosthetic alveolar ridge reconstruction with autologous bone grafts.

Methods

A consecutive retrospective study was conducted on all patients who were treated at the military outpatient clinic of the Department of Oral and Plastic Maxillofacial Surgery at the military hospital in Ulm (Germany) in the years of 2009 until 2011 with autologous bone transplantation prior to secondary implant insertion. Intraoral donor sites (crista zygomatico-alveolaris, ramus mandible, symphysis mandible, and anterior sinus wall) and extraoral donor site (iliac crest) were used. A total of 279 patients underwent after a healing period of 3–5 months routinely computer tomography scans followed by virtual implant planning. The implants were inserted using guided oral implantation as described by Naziri et al. All records of all the consecutive patients were reviewed according to patient age, history of periodontitis, smoking status, jaw area and dental situation, augmentation method, intra- and postoperative surgical complications, and surgeon’s qualifications. Evaluated was the augmentation surgical outcome regarding bone graft loss and early implant loss postoperatively at the time of prosthodontic restauration as well a follow-up period of 2 years after loading.

Results

A total of 279 patients underwent 456 autologous augmentation procedures in 546 edentulous areas. One hundred thirteen crista zygomatico-alveolaris grafts, 104 ramus mandible grafts, 11 symphysis grafts, 116 grafts from the anterior superior iliac crest, and 112 sinus lift augmentations with bone scrapes from the anterior facial wall had been performed. There was no drop out or loss of follow-up of any case that had been treated in our clinical center in this 3-year period. Four hundred thirty-six (95.6%) of the bone grafts healed successfully, and 20 grafts (4.4%) in 20 patients had been lost. Fourteen out of 20 patients with total graft failure were secondarily re-augmented, and six patients wished no further harvesting procedure. In the six patients, a partial graft resorption was detected at the time of implantation and additional simultaneous augmentation during implant insertion was necessary. No long-term nerve injury occurred. Five hundred twenty-five out of 546 initially planned implants in 259 patients could be inserted into successfully augmented areas, whereas 21 implants in 20 patients due to graft loss could not be inserted. A final rehabilitation as preplanned with dental implants was possible in 273 of the 279 patients. The early implant failure rate was 0.38% concerning two out of the 525 inserted implants which had to be removed before the prosthodontic restoration. Two implants after iliac crest augmentation were lost within a period of 2 years after loading, concerning a total implant survival rate after 2 years of occlusal loading rate of 99.6% after autologous bone augmentation prior to implant insertion.

Conclusions

This review demonstrates the predictability of autologous bone material in alveolar ridge reconstructions prior to implant insertion, independent from donor and recipient site including even autologous bone chips for sinus elevation. Due to the low harvesting morbidity of autologous bone grafts, the clinical results of our study indicate that autologous bone grafts still remain the “gold standard” in alveolar ridge augmentation prior to oral implantation.

Influence of Lateral-Medial Sinus Width on No-Grafting Inlay Osteotome Sinus Augmentation Outcomes

PURPOSE

Intrasinus new bone formation (BF) has been observed after no-grafting osteotome sinus augmentation, and it is hypothesized to be influenced by the dimensions of the maxillary sinus. The aim of this clinical trial is to evaluate the influence of lateral-medial sinus width (SW) on no-grafting osteotome sinus augmentation outcomes using cone-beam computed tomography.

PATIENTS AND METHODS

All patients recruited for this prospective study were treated with no-grafting osteotome sinus augmentation with simultaneous implant placement. Cone-beam computed tomography was obtained before, immediately after, and 6 months after the surgical procedure to use for measurements. Descriptive statistics were calculated and univariate, bivariate, and multivariate analysis were conducted to evaluate the influence of average SW and other relevant factors on procedure outcomes, including new BF, residual bone resorption (BR), and change of peri-implant bone height (CPBH).

RESULTS

A total of 48 implants placed in 32 elevated sinuses of 29 patients were included. The average SW was 11.3 ± 1.8 mm. Intrasinus BF measured 1.7 ± 0.9 mm at 6 months after surgery. The amount of BR was 0.3 ± 0.9 mm, and CPBH was calculated as 1.3 ± 1.3 mm. Multivariate analysis showed a negative correlation between SW and BF (r = -0.469, P = .001), as well as between SW and CPBH (r = -0.562, P = .001). A positive correlation was discovered between SW and BR (r = 0.311, P = .027) in general.

CONCLUSIONS

The lateral-medial SW was observed to have a negative correlation with new BF and CPBH after no-grafting osteotome sinus augmentation.

Histologic and histomorphometric evaluation of two grafting materials Cenobone and ITB-MBA in open sinus lift surgery

Aims and Objectives:

Alveolar ridge reduction caused after tooth extraction can be minimized through ridge preservation and application of graft materials. The aim of this study was to compare the histologic and histomorphometric aspects of bone particulated allografts, Cenobone and ITB-MBA, in the reconstruction of vertical alveolar ridge after maxillary sinus augmentation.

Materials and Methods:

This clinical trial was performed among 20 patients. The participants were randomly divided into two groups of 10 participants. The first group received Cenobone and the second group received ITB-MBA. Tissue samples were prepared 6 months later at the time of implant installation and after successful maxillary sinus floor augmentation. Tissue sections were examined under a light microscope. The data were analyzed by Chi-square and t-test.

Results:

The mean trabecular thickness of the samples in the Cenobone group was 13.61 ± 7.47 μm compared to 13.73 ± 7.37 μm in the ITB-MBA group (P = 0.93). A mild inflammation process (Grade 1) was detected in both the groups. The amount of remaining biomaterial in the Cenobone group was estimated to be 8 ± 19% vs. 7 ± 12% in the ITB-MBA group (P = 0.30). Bone formation was reported 49.71% in the Cenobone group vs. 40.76% in the ITB-MBA group (P = 0.68). The mean newly formed vessel in the Cenobone group was 0.64 ± 0.7 vs. 1.5 ± 2.3 in the ITB-MBA group (P = 0.14).

Conclusions:

There was no significant difference between the two groups of patients regarding trabecular thickness, remaining biomaterial allograft, and the density of blood vessels after sinus floor elevation; hence, there was no difference between the two groups regarding implant outcome. More designed studies as randomized controlled trials and controlled clinical trials, which evaluate the long-term implant outcome; comparing the different bone graft materials is also required to improve evidence on survival and success rate.

Bovine bone matrix/poly(l-lactic-co-ε-caprolactone)/gelatin hybrid scaffold (SmartBone®) for maxillary sinus augmentation: A histologic study on bone regeneration

The ideal scaffold for bone regeneration is required to be highly porous, non-immunogenic, biostable until the new tissue formation, bioresorbable and osteoconductive. This study aimed at investigating the process of new bone formation in patients treated with granular SmartBone^® for sinus augmentation, providing an extensive histologic analysis. Five biopsies were collected at 4-9 months post SmartBone^® implantation and processed for histochemistry and immunohistochemistry. Histomorphometric analysis was performed. Bone-particle conductivity index (BPCi) was used to assess SmartBone^® osteoconductivity. At 4 months, SmartBone^® (12%) and new bone (43.9%) were both present and surrounded by vascularized connective tissue (37.2%). New bone was grown on SmartBone^® (BPCi=0.22). At 6 months, SmartBone^® was almost completely resorbed (0.5%) and new bone was massively present (80.8%). At 7 and 9 months, new bone accounted for a large volume fraction (79.3% and 67.4%, respectively) and SmartBone^® was resorbed (0.5% and 0%, respectively). Well-oriented lamellae and bone scars, typical of mature bone, were observed. In all the biopsies, bone matrix biomolecules and active osteoblasts were visible. The absence of inflammatory cells confirmed SmartBone^® biocompatibility and non-immunogenicity. These data indicate that SmartBone^® is osteoconductive, promotes fast bone regeneration, leading to mature bone formation in about 7 months.

Long-term Evaluation of Peri-implant Bone Level after Reconstruction of Severely Atrophic Edentulous Maxilla via Vertical and Horizontal Guided Bone Regeneration in Combination with Sinus Augmentation: A Case Series with 1 to 15 Years of Loading

BACKGROUND

To the best of the authors' knowledge, there is very limited clinical data on the outcomes of simultaneous guided bone regeneration (GBR) for horizontal and/or vertical bone gain for the reconstruction of severely atrophic edentulous maxilla. Therefore, the purpose of the clinical series presented herein was to clinically evaluate long-term horizontal and vertical bone gain, as well as implant survival rate after reconstruction of severely atrophic edentulous maxillary ridges.

MATERIAL AND METHODS

Sixteen patients (mean age: 64.6 ± 14.6 years of age) were consecutively treated for vertical and/or horizontal bone augmentation via GBR in combination with bilateral sinus augmentation utilizing a mixture of autologous and anorganic bovine bone. Implant survival, bone gain, intraoperative/postoperative complications and peri-implant bone loss were calculated up to the last follow-up exam.

RESULTS

Overall, 122 dental implants were placed into augmented sites and have been followed from 12 to 180 months (mean: 76.5 months). Implant survival was 100% (satisfactory survival rate of 97.5%). Mean bone gain was 5.6 mm (max: 9 mm; min: 3 mm) While vertical bone gain was 5.1 ± 1.8 mm; horizontal bone gain was 7.0 ± 1.5 mm. No intraoperative/postoperative complications were noted. Mean peri-implant bone loss values were consistent within the standards for implant success (1.4 ± 1.0 mm). At patient-level, only one patient who had three implants presented with severe peri-implant bone loss.

CONCLUSION

Complete reconstruction of an atrophied maxilla can be successfully achieved by means of guided bone regeneration for horizontal and/or vertical bone gain including bilateral sinus augmentation using a mixture of anorganic bovine bone and autologous bone.

Accuracy of cone beam computed tomography in following simulated autogenous graft resorption in maxillary sinus augmentation procedure: an ex vivo study

OBJECTIVES:

Maxillary sinus augmentation is a well-documented procedure with long-term success in implant dentistry. Assessing graft volume changes over time is crucial, since resorption remains a major concern. CBCT is commonly employed to assess the quantity and quality of the available bone at the implant receptor site. However, its applicability in following graft volume changes is yet to be determined. The study aimed to assess CBCT accuracy in following simulated graft resorption ex vivo.

METHODS:

4 differently sized autogenous bone blocks harvested from the zygomatic buttress were bilaterally placed in the maxillary sinus of 12 human cadavers. The Accuitomo (J Morita, Kyoto, Japan) CBCT system was employed to scan each one of the 4 grafts in each of the 12 cadavers using identical settings. Gold standard graft measurements were obtained using micro-CT. One independent observer assessed the volume of each graft on CBCT images twice. Intraobserver reliability was assessed using Cohen's kappa and one-sample t-test was used to compare CBCT with micro-CT volumetric measurements.

RESULTS:

The mean micro-CT graft volumes were 97.12 ± 1.4, 197.32 ± 3.4, 361.41 ± 4.2 and 1040.11 ± 3.2 mm³ for Grafts 1-4, respectively, and the mean CBCT volumes of the corresponding grafts were 115.39 ± 7.01, 205.97 ± 9.91, 404.05 ± 16.81 and 1138.04 ± 20.98 mm³. CBCT measurements were statistically significantly different from micro-CT measurements (p = 0.001). Intraobserver reliability was good (r = 0.78).

CONCLUSIONS:

In every case, CBCT overestimated the maxillary graft volume in comparison with micro-CT. However, the measurement differences were limited and might not influence clinical performance.

Removal of phosphate from aqueous solution by SiO2–biochar nanocomposites prepared by pyrolysis of vermiculite treated algal biomass

The present work describes the fabrication of SiO₂–biochar nanocomposites by pyrolysis of vermiculite treated algal biomass.

Effect of the Schneiderian membrane on the formation of bone after lifting the floor of the maxillary sinus: an experimental study in dogs

A titanium membrane was used to isolate the Schneiderian membrane of the bony walls of the sinus so that we could investigate their role on the formation of bone after sinus lifts compared with a control group (conventional raising of the sinus floor) in which we did not use a membrane to isolate any area. Three canine models of lifting the sinus floor using the lateral window technique were established: conventional lifting of the floor (control group), raising of the floor with the mucosa shielded (mucosal shielding group), and raising of the floor with the bony wall shielded (bony wall shielding group). The formation of bone one and three months after the sinus floor had been lifted was compared in each group both grossly and by histopathological examination. An appreciable amount of new bone had formed in the control group, with abundant areas near the inferior bony wall, and some near the raised Schneiderian membrane. Similarly, new bone had also formed in the mucosal shielding group, with abundant new bone near the inferior bony wall, but none near the raised Schneiderian membrane. However, there was considerably less new bone in the bony wall shielding group, with none in tissues adjacent to the inferior bony wall and little in tissues near the raised Schneiderian membrane. The Schneiderian membrane has osteogenic capability and participates in the formation of bone after the sinus floor has been lifted. However, its osteogenic role is weaker than that of the surrounding bony wall of the maxillary sinus.

Avaliação histomorfométrica da associação entre biovidro e osso bovino liofilizado no tratamento de defeitos ósseos críticos criados em calvárias de ratos. Estudo piloto

OBJETIVO: Avaliar histomorfometricamente o efeito de biovidro (B), osso bovino liofilizado (OB) ou da mistura desses dois biomateriais (B/OB - 1:1) no reparo de defeitos ósseos críticos em calvária de ratos. MATERIAL E MÉTODO: Defeitos ósseos (8 mm Ø) foram criados cirurgicamente na calvária de 24 ratos, distribuídos em 4 grupos com 6 animais, de acordo com o tipo de biomaterial: coágulo sanguíneo (GC), biovidro (GB), osso bovino liofilizado (GOB) e a mistura desses dois biomateriais (GB/OB). Os animais foram eutanasiados após 15 e 60 dias do procedimento cirúrgico (3 animais por período). A avaliação histológica foi baseada na descrição da morfologia dos tecidos neoformados, enquanto para a avaliação histomorfométrica foi realizada quantificação da porcentagem de tecido ósseo, de tecido conjuntivo fibroso neoformados e de biomaterial remanescente no defeito ósseo. RESULTADO: Nos dois períodos experimentais, a análise histológica apresentou neoformação óssea, principalmente nas bordas dos defeitos, e ao redor de partículas de biomateriais remanescentes. A avaliação histomorfométrica demonstrou que no período de 15 dias o grupo GC apresentou maior percentagem de tecido ósseo em relação aos demais grupos estudados, enquanto que aos 60 dias o grupo GOB apresentou maior porcentagem de tecido ósseo em relação ao grupo GB. CONCLUSÃO: O osso bovino liofilizado apresentou maior formação óssea em relação ao biovidro, mas nenhum dos biomateriais foi superior ao coágulo. A associação do biovidro e osso bovino liofilizado não adicionou vantagem à formação óssea.

A simplified approach to the minimally invasive antral membrane elevation technique utilizing a viscoelastic medium for hydraulic sinus floor elevation

PURPOSE

Maxillary sinus augmentation surgery is frequently employed to provide adequate vertical bony dimensions in posterior maxillary sites. When significant gain in bone height is sought for, an invasive lateral-window approach is routinely used to achieve sinus floor elevation. The minimally invasive antral membrane elevation technique was initially conceived as a surgical improvisation that has been shown to lead to up to, or exceeding, 10 mm of bone height, while enhancing the safety profile of the transalveolar sinus augmentation technique. This approach is based on the use of hydraulic pressure that is applied to the schneiderian membrane via a saline-inflatable balloon. Even though this technique has been shown to be a safe and efficacious treatment modality, the need for specialized equipment, training, and corresponding costs may hinder its widespread application. The purpose of this clinical paper is to introduce a simplified approach to the minimally invasive antral membrane elevation technique.

METHODS

The simplified minimally invasive antral membrane elevation technique is based on the application of hydraulic pressure by a viscous bone graft that acts as an incompressible fluid. The specific clinical steps of this technique will be demonstrated to illustrate how grafting of the maxillary sinus is achieved simultaneously with the atraumatic elevation of the schneiderian membrane, thus resulting in even less operative time.

CONCLUSIONS

This simplified technique may make the minimally invasive antral membrane elevation technique more accessible to implant surgeons as it eliminates the need for purchase of specialized equipment and aids in further decrease of intra-operative time accomplished with the original technique.

A clinical and radiographic case series of implants placed with the simplified minimally invasive antral membrane elevation technique in the posterior maxilla

The aim of the present case series was to evaluate a simplified minimally invasive transalveolar sinus elevation technique utilizing calcium phosphosilicate (CPS) putty for hydraulic sinus membrane elevation. The simplified minimally invasive antral membrane elevation technique is based on the application of hydraulic pressure via a viscous bone graft that acts as an incompressible fluid. In this retrospective study, 21 patients (mean age: 48.5 ± 12 years) consecutively treated with the simplified minimally invasive transalveolar sinus elevation technique were evaluated. 28 tapered implants were placed in posterior maxillary sites with less than 6 mm of residual bone height as determined radiographically on cone beam volumetric tomographs. No sinus membrane perforations were noted and none of the patients complained of symptoms of sinusitis post-operatively (0%). The mean gain in bone height post-operatively was 10.31 ± 2.46 mm (p < 0.001). All implants successfully integrated (100% success rate) and were loaded with cement-retained prostheses. The proposed technique is a simple, efficacious, minimally invasive approach for sinus elevation that can be recommended for sites with at least 3 mm of residual height.

Effect of maxillary sinus floor augmentation without bone grafts

Objective:

The objective of the present review was to determine the effectiveness of maxillary sinus floor augmentation without bone grafts using lateral window technique.

Materials and Methods:

PubMed and Cochrane databases were searched for relevant articles. We also included articles by hand search until June 2012. The analysis included both human and animal studies which satisfied the following criteria: Minimum of 6 months follow-up, no use of bone grafts, and lateral window approach to the sinus.

Results:

We included 22 articles in the review. A descriptive analysis of the constructed evidence tables indicated that there is evidence of predictable a mount of bone formation in the maxillary sinus augmentation without the use of bone grafts.

Conclusion:

Within the limits of the articles and data available, maxillary sinus augmentation without bone graft might be considered effective inpredictable bone formation.

Porous titanium granules in critical size defects of rabbit tibia with or without membranes

Recently, porous titanium granules (PTGs) have been indicated for the preservation of the dimensions of post-extraction sockets, as a filler in sinus lift procedures and for the treatment of peri-implant and periodontal defects, based on the osteoconductivity and dimensional stability of the titanium granules. However, there is a lack of information regarding the use of this material in larger defects and in conjunction with membranes. The objective of this study is to test the behavior of PTGs used to fill critical size defects in rabbit tibiae, with and without membranes. Critical defects were created in both tibiae of rabbits, divided randomly into three groups: Group A (defect filled with PTG), Group B (defect filled with PTG+collagen membrane) and a control group (empty defect). After six weeks, histomorphometric analysis was performed. The results showed more defect closures at the cortical area (87.37%±2.2%) and more bone formation at the marrow area (57.6%±1.3%) in Group B, in comparison with the other groups (P<0.05); the use of membranes improved the material stability expressed as more percentages of the original material when membranes were used (P<0.05). Finally, inflammatory reactions were observed when the granules were not protected by membranes. In spite of the limitations of this animal study, it may be concluded that PTG particles are osteoconductive and allow bone growth. The PTG particles must be covered by a membrane, especially when grafting larger defects, in order to control particle migration, promote clot stabilization and separate the PTG graft from undesired soft tissue cells.

Preconditioned 70S30C bioactive glass foams promote osteogenesis in vivo

Bioactive glass scaffolds (70S30C; 70% SiO2 and 30% CaO) produced by a sol-gel foaming process are thought to be suitable matrices for bone tissue regeneration. Previous in vitro data showed bone matrix production and active remodelling in the presence of osteogenic cells. Here we report their ability to act as scaffolds for in vivo bone regeneration in a rat tibial defect model, but only when preconditioned. Pretreatment methods (dry, pre-wetted or preconditioned without blood) for the 70S30C scaffolds were compared against commercial synthetic bone grafts (NovaBone® and Actifuse®). Poor bone ingrowth was found for both dry and wetted sol-gel foams, associated with rapid increase in pH within the scaffolds. Bone ingrowth was quantified through histology and novel micro-CT image analysis. The percentage bone ingrowth into dry, wetted and preconditioned 70S30C scaffolds at 11 weeks were 10±1%, 21±2% and 39±4%, respectively. Only the preconditioned sample showed above 60% material-bone contact, which was similar to that in NovaBone and Actifuse. Unlike the commercial products, preconditioned 70S30C scaffolds degraded and were replaced with new bone. The results suggest that bioactive glass compositions should be redesigned if sol-gel scaffolds are to be used without preconditioning to avoid excess calcium release.