Lateral alveolar ridge augmentation using a synthetic nano-crystalline hydroxyapatite bone substitution material (Ostim®). Preliminary clinical and histological results

Complications following alveolar ridge augmentation procedures

Oral rehabilitation through implant supported dental restorations often requires a ridge augmentation procedure (RAP) prior to implant fixture placement since tooth extraction/loss results in alveolar ridge deficiencies. Although RAP-related surgical techniques and biomaterials have been in practice for several decades, outcomes are not always predictable. Post-surgical complications experienced during the early or late wound healing phases may jeopardize the targeted ideal ridge dimensions, required for implant fixture placement, and may have other consequences, such as negatively impacting the patient's quality of life. This review describes reported post-surgical complications following RAP under the following subtitles: complications by tissue type, complications in function and aesthetics, complications by healing time, complications by biomaterial type, and complications by surgical protocol modalities. Specifically, RAP performed by using particulate bone graft substitutes and related complications are explored. Modalities developed to prevent/manage these complications are also discussed.

Hydroxyapatite-based composites: Excellent materials for environmental remediation and biomedical applications

Given their unique characteristics and properties, Hydroxyapatite (HAp) nanomaterials and nanocomposites have been used in diverse advanced catalytic technologies and in the field of biomedicine, such as drug and protein carriers. This paper examines the structure and properties of the manufactured HAp as well as a variety of synthesis methods, including hydrothermal, microwave-assisted, co-precipitation, sol-gel, and solid-state approaches. Additionally, the benefits and drawbacks of various synthesis techniques and ways to get around them to spur more research are also covered. This literature discusses the various applications, including photocatalytic degradation, adsorptions, and protein and drug carriers. The photocatalytic activity is mainly focused on single-phase, doped-phase, and multi-phase HAp, while the adsorption of dyes, heavy metals, and emerging pollutants by HAp are discussed in the manuscript. Furthermore, the use of HAp in treating bone disorders, drug carriers, and protein carriers is also conferred. In light of this, the development of HAp-based nanocomposites will inspire the next generation of chemists to improve upon and create stable nanoparticles and nanocomposites capable of successfully addressing major environmental concerns. This overview's conclusion offers potential directions for future study into HAp synthesis and its numerous applications.

Titanium Mesh Exposure After Bone Grafting: Treatment Approaches-A Systematic Review

Study Design

A systematic review according to PRISMA statement has been designed to answer the preliminary question: "In titanium mesh exposures, is there a treatment alternative which leads to an increased graft maintenance?" and fill the PICO assessment out.

Objective

To review studies published in the past 20 years (1999-2019) in which mesh exposure has occurred, detecting the suitable approaches to treat exposure allowing the graft maintenance.

Methods

Initial search on PUBMED, SCOPUS, and COCHRANE databases resulted in 777 articles, and hand-searching identified 6 articles. After removing duplicates and unrelated articles, eligibility criteria were applied, and 31 studies were selected (randomized clinical trials, retrospective/prospective clinical trials, and case series).

Results

A total of 677 surgical sites and 225 cases of mesh exposure were identified. Eleven treatments have been identified. Chlorhexidine was the primary approach in 46% of cases, followed by oral hygiene instructions and follow-up with 22.5% of occurrences. In 21% of clinical situations, titanium mesh removal was the treatment of choice, associated with other measures (i.e., antibiotic prescription). There seems to be a consensus in cases of infection. When this complication was associated with tissue dehiscence, the primary treatment was mesh removal. The same does not occur when the site needs to be cleaned for long-term periods.

Conclusion

In 2 decades of use of titanium meshes, the available treatments do not seem to have evolved, and there is not enough data to establish a guideline.

Nanocrystalline hydroxyapatite in periodontal bone regeneration: A systematic review

Background

Periodontal diseases when persistent, results in periodontal pockets, attachment loss and progressive destruction of the alveolar bone. Grafting periodontal bone defects with bone substitute biomaterials has proven clinical success for accomplishing reconstruction of lost attachment apparatus, especially in deep intra-bony defects. Nanoparticles (NPs) have been considered indispensable in the future of health sciences and NP based alloplastic graft materials such as nanocrystalline hydroxyapatite (NCHA) hold great promise for regeneration of periodontal defects. Therefore the aim of this review is to evaluate the role of NCHA as an effective substitute for periodontal bone regeneration.

Material & methods

Popular scientific databases such as PubMed (Medline), Cochrane database of clinical trials, Scopus (Elsevier), Web of science (Clarivate Analytics) and Google Scholar, were searched. The literature search was restricted to published reports in English, between January 2000 and December 2021. Database search returned 1227 results which were screened based on title, author names and publication dates.

Results

Data from the 14 included studies were reviewed and tabulated. In the present review, all the studies reported using commercially available NCHA for periodontal bone regeneration.

Conclusion

NCHA is a suitable bone substitute material for periodontal bone regeneration, with outcomes comparable to that of conventionally used graft materials such as bovine xenograft and other synthetic alloplastic materials. While grafting with NCHA in intrabony periodontal defects, after any form of periodontal flap surgery or debridement, significantly improves bone regeneration by 6 months, addition of adjuncts like EMD and PRF further enhance the outcomes.

In situ preparation of hydroxyapatite in lamellar liquid crystals for joint lubrication and drug delivery

Arthritis is a disease that seriously affects the quality of human life, which is partly caused by the reduction of joint lubrication performance. Thus, for the treatment of arthritis, how to improve the lubrication performance of joints is important. The lamellar liquid crystals (LLCs) systems have the potential to be used as joint lubrication due to their double-layer structure and good biocompatibility, however, the LLCs system alone could not provide a satisfactory lubrication effect. Herein, this work synthesized hydroxyapatite (HAP) in situ inside Tween 85/Tween 80/H₂O LLCs to construct a biocompatible HAP/Tween 85/Tween 80/H₂O LLCs (HAP/LLCs) lubrication system with both sustained drug release properties and anti-wear properties. HAP is the main component of bone with good stability and bioactivity. The LLCs have good lubricating and drug-carrying properties. The impact of HAP on the structure and lubrication properties of LLCs, the mechanism of friction, and the anti-wear reduction of HAP/LLCs were investigated. Moreover, the drug release behavior of the ibuprofen-loaded HAP/LLCs during the friction process was also studied. The results indicated that the addition of HAP could improve the lubricity performance of LLCs. The cumulative drug releasing increased with the friction frequency and was less affected by the load. The related studies provided the theoretical basis for HAP/LLCs for joint lubrication and synergistic therapy.

Histomorphometric Analysis of Differential Regional Bone Regeneration Induced by Distinct Doped Membranes

Our objective is to evaluate the regional regenerative potential of calvarial bone in critical-sized defects in a rabbit model using novel nanostructured silica-loaded membranes doped with zinc or doxycycline. Nanostructured membranes of (MMA)₁-co-(HEMA)₁/(MA)₃-co-(HEA)₂ loaded with 5 wt% of SiO₂ nanoparticles (HOOC-Si-Membranes) were doped with zinc (Zn-HOOC-Si-Membrane) or doxycycline (Dox-HOOC-Si-Membrane). Critical bone defects were created on six New-Zealand-breed rabbit skulls and covered with the membranes. A sham defect without a membrane was used as the control. After six weeks, a histological analysis (toluidine blue technique) was employed to determine the area percentages of newly formed bone, osteoid bone, and soft tissue. The measurements were performed by dividing the total defect area into top (close to the membrane) and bottom (close to the dura mater) regions, or peripheral (adjacent to the old bone) and central (the sum of the remaining zones) regions. The peripheral regions of the defects showed higher osteogenic capacity than the central areas when the membranes were present. The proportion of new bone adjacent to the dura was similar to that adjacent to the membrane only when the HOOC-Si-Membranes and Zn-HOOC-Si-Membranes were used, indicating a direct osteoinductive effect of the membranes.

Horizontal augmentation techniques in the mandible: a systematic review

Purpose

Placement of dental implants has evolved to be an advantageous treatment option for rehabilitation of the fully or partially edentulous mandible. In case of extensive horizontal bone resorption, the bone volume needs to be augmented prior to or during implant placement in order to obtain dental rehabilitation and maximize implant survival and success.

Methods

Our aim was to systematically review the available data on lateral augmentation techniques in the horizontally compromised mandible considering all grafting protocols using xenogeneic, synthetic, or allogeneic material. A computerized and manual literature search was performed for clinical studies (published January 1995 to March 2021).

Results

Eight studies ultimately met the inclusion criteria comprising a total of 276 procedures of xenogeneic, allogeneic, or autogenous bone graft applications in horizontal ridge defects. Particulate materials as well as bone blocks were used as grafts with a mean follow-up of 26.0 months across all included studies. Outcome measures, approaches and materials varied from study to study. A gain of horizontal bone width of the mandible with a mean of 4.8 mm was observed in seven of eight studies. All but one study, reported low bone graft failure rates of 4.4% in average.

Conclusions

Only limited data are available on the impact of different horizontal augmentation strategies in the mandible. The results show outcomes for xenogeneic as well as autologous bone materials for horizontal ridge augmentation of the lower jaw. The use of allogeneic bone-block grafts in combination with resorbable barrier membranes must be re-evaluated. Randomized controlled clinical trials are largely missing.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40729-022-00421-7.

Nanocrystalline hydroxyapatite in regeneration of periodontal intrabony defects: A systematic review and meta-analysis

BACKGROUND

Alveolar bone loss and mobility of teeth is commonly observed in periodontitis patients. Regeneration of periodontal intrabony defects is indicated to restore the lost bone and periodontal tissues. The aim of the present study was to evaluate the clinical outcomes of periodontal intrabony lesions by using nanocrystalline hydroxyapatite (NHA) graft and comparing it with open flap debridement (OFD) alone.

MATERIALS AND METHODS

The eligibility criteria encompassed randomized (RCTs) and controlled clinical trials (CCTs). Weighted mean differences were calculated for clinical attachment level (CAL) gain, probing pocket depth (PPD) reduction and gingival recession (REC) change, demonstrated as forest plots. The revised Cochrane Risk of Bias tool for randomized trials (RoB2) and Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I) tool were used for quality assessment of RCTs and non-randomized trials respectively.

RESULTS

From 22 full-text articles identified, three RCTs, one CCT and one retrospective follow-up of RCT were included. All the five papers comprised the quantitative evaluation. The use of NHA graft provided additional CAL gain of 0.96 mm (p = 0.0009) and PPD reduction of 0.97 mm (p < 0.00001) when compared to OFD alone. However, in terms of REC changes, no considerable benefits of NHA graft were demonstrated than OFD alone (p = 0.48).

CONCLUSIONS

The bioactive NHA graft showed promising results clinically in regenerative periodontology and can be considered for the management of periodontal intrabony defects. The use of NHA graft considerably provided better clinical outcomes in intrabony defects compared to using the OFD alone. Future research investigating NHA graft against other regenerative materials including specific BGs, at longer follow-up periods and bigger sample sizes and in furcation defects warranted.

Expression of Vascular Endothelial Growth Factor Using Platelet Rich Fibrin (PRF) and Nanohydroxyapatite (nano-HA) in Treatment of Periodontal Intra-Bony Defects - A Randomized Controlled Trial

The study aims to assess the concentration of vascular endothelial growth factors (VEGF) with platelet rich fibrin (PRF) biomaterial, while using it separately or in combination with nanohydroxyapatite (nano-HA) for treating intra-bony defects (IBDs) using radiographic evaluation (DBS-Win software). Sixty patients with IBD (one site/patient) and chronic periodontitis were recruited randomly to test either autologous PRF platelet concentrate, nano-HA bone graft, a combination of PRF platelet concentrate and nano-HA, or alone conventional open flap debridement (OFD). Recordings of clinical parameters including probing depth (PD), gingival index (GI), and clinical attachment level (CAL) were obtained at baseline and 6 months, post-operatively. One-way analysis of variance (ANOVA) was used to compare four groups; whereas, multiple comparisons were done through Tukey’s post hoc test. The results showed that CAL at baseline changed from 6.67 ± 1.23 to 4.5 ± 1.42 in group I, 6.6 ± 2.51 to 4.9 ± 1.48 in group II, 5.2 ± 2.17 to 3.1 ± 1.27 in group III, and 4.7 ± 2.22 to 3.7 ± 2.35 in group IV after 6 months. The most significant increase in bone density and fill was observed for IBD depth in group III that was recorded as 62.82 ± 24.6 and 2.31 ± 0.75 mm, respectively. VEGF concentrations were significantly increased at 3, 7, and 14 days in all groups. The use of PRF with nano-HA was successful regenerative periodontal therapy to manage periodontal IBDs, unlike using PRF alone. Increase in VEGF concentrations in all group confirmed its role in angiogenesis and osteogenesis in the early stages of bone defect healing.

Clinical comparison of different flap advancement techniques to periosteal releasing incision in guided bone regeneration: A randomized controlled trial

OBJECTIVES

To compare Double Flap Incision (DF), Coronally Advanced Lingual Flap (CALF), and Modified Periosteal Releasing Incision (MPRI) to Periosteal Releasing Incision (PRI) in flap advancement, postoperative complications in augmentation using titanium mesh.

MATERIAL AND METHODS

Forty patients with partially edentulous posterior mandibles were randomly assigned to the four groups. We evaluated: (a) Flap advancement in mm (Primary outcome). (b) Pain using the Numerical Rating scale (NRS). (c) Swelling using the Visual Analogue Scale (VAS). (d) Exposure in mm and exposure percentage at 1 week to 6 months.

RESULTS

The CALF showed the highest mean flap advancement of 19.9 (±5.0) mm while the PRI showed the lowest; 10.2 (±1.7) mm. The difference between groups was statistically significant (P value <.0001). MPRI showed the highest pain score of 5.3 (±1.3) while the DF showed the lowest; 2.39 (±1.7). Swelling did not show a significant difference between groups. MPRI showed the highest exposure mean; 18.6 mm (±26.3) while CALF showed the lowest; 2.5 mm (±4.0). PRI showed the highest exposure percentage; 7.4% (±9.3) while CALF showed the lowest; 0.4% (±0.7). The difference between groups was insignificant.

CONCLUSIONS

CALF reported highest advancement, least complications while PRI reported the highest complications.

Histological and histomorphometric evaluation of hydroxyapatite-based biomaterials in surgically created defects around implants in dogs

BACKGROUND

The present study evaluated histologically and histometrically the efficacy of micro-, nano-, or mixed-composite of hydroxyapatite (HA) graft in treatment of surgically created defects around dental implants in mongrel dogs.

METHODS

Immediate implant was used after extraction of the lower third premolar in mongrel male dogs. Critical-size defects were created in intact proximal alveolar bone to each implant. The defects were divided randomly into four groups of two animals based on biomaterials used for treatment: 1) received no treatment (negative control); 2) defects treated with nano-HA bone graft; 3) defects treated with micro-HA bone graft; and 4) defects treated with a mixed composite of micro-HA and nano-HA. Animals were sacrificed at 2 months and histologic and histometric evaluation was performed.

RESULTS

The amount of new bone formed with nano-HA bone graft was highly more significant than that obtained by a micro- or mixed-composite of hydroxyapatite. Defects treated by mixed hydroxyapatite showed the greatest value in mean area percentage of collagen fibers using Masson trichrome stain.

CONCLUSIONS

The present study demonstrated that nano-hydroxyapatite bone graft was better than micro-HA or mixed-HA bone graft in new bone formation in standardized surgically created defects around dental implants. However, longer period is necessary to determine the time taken for complete resorption of bone graft materials and their replacement with new bone.

Comparison of allogeneic and autogenous bone grafts for augmentation of alveolar ridge defects-A 12-month retrospective radiographic evaluation

OBJECTIVES

The aim of this study was to compare three-dimensional alterations following the use of autogenous versus allogeneic onlay grafts for augmentation at single tooth defects.

MATERIALS AND METHODS

Alveolar bone width at specific implant sites were assessed using sagittal and cross-sectional CBCT images prior grafting and at three subsequent time points. Twenty-one patients received autogenous bone blocks harvested from the retromolar region and another 21 patients received freeze-dried cancellous allogeneic bone blocks.

RESULTS

The vertical and horizontal dimensions did not significantly differ between autogenous and allogeneic bone grafts at any time point. In addition, there were no statistically significant differences in graft remodeling rates between autogenous (mean shrinkage rate after 12 months: 12.5% ± 7.8%) and allogeneic onlay grafts (mean shrinkage rate after 12 months: 14.4% ± 9.8%).

CONCLUSIONS

Freeze-dried cancellous allogeneic bone blocks showed equivalent volumetric shrinkage rates as autogenous bone blocks when used for treating circumscribed bone defects classified as Type-II to Type-IV according to the ITI-treatment guide categories. Therefore, it is not necessary to over-contour the alveolar ridge when using allogeneic blocks for treating single tooth defects, but to apply the same procedure as when using autogenous blocks.

Application of hydroxyapatite and its modified forms as adsorbents for water defluoridation: an insight into process synthesis

Fluorosis is a major scourge in many countries caused by prolonged consumption of drinking water with high fluoride content found in groundwater resources. Hydroxyapatite (Hap) and its composite forms are excellent biomaterials that recently gained attention as efficient adsorbents, owing to its physical and chemical nature as it can substitute both cationic and anionic complexes present in an aqueous solution in its atomic arrangement. Its biological nature, biocompatibility and biodegradability along with its chemical characteristics such as crystallinity, stability, ion adsorption capability and highly specific catalytic activity make it suitable for a variety of applications especially in water treatment for fluoride removal. This review describes various techniques for synthesis of a wide variety of biogenic, synthetic, composite and modified forms of Hap for application in water defluoridation. Hap derived from natural sources or synthesized using conventional methods, hydrothermal, sol-gel or advanced sonication-cum-precipitation technique varied in terms of its crystallinity, structure, size, etc., which affect the fluoride removal capacity. The advantage and disadvantages of various synthesis methods, process parameters and product characteristics have been compiled, which may help to identify a suitable synthesis method for a desired Hap product for potential application and future perspectives in water treatment.

Review of potential health risks associated with nanoscopic calcium phosphate

Calcium phosphate is applied in many products in biomedicine, but also in toothpastes and cosmetics. In some cases, it is present in nanoparticulate form, either on purpose or after degradation or mechanical abrasion. Possible concerns are related to the biological effect of such nanoparticles. A thorough literature review shows that calcium phosphate nanoparticles as such have no inherent toxicity but can lead to an increase of the intracellular calcium concentration after endosomal uptake and lysosomal degradation. However, cells are able to clear the calcium from the cytoplasm within a few hours, unless very high doses of calcium phosphate are applied. The observed cytotoxicity in some cell culture studies, mainly for unfunctionalized particles, is probably due to particle agglomeration and subsequent sedimentation onto the cell layer, leading to a very high local particle concentration, a high particle uptake, and subsequent cell death. There is no risk from an oral uptake of calcium phosphate nanoparticles due to their rapid dissolution in the stomach. The risk from dermal or mucosal uptake is very low. Calcium phosphate nanoparticles can enter the bloodstream by inhalation, but no adverse effects have been observed, except for a prolonged exposition to high particle doses. Calcium phosphate nanoparticles inside the body (e.g. after implantation or due to abrasion) do not pose a risk as they are typically resorbed and dissolved by osteoclasts and macrophages. There is no indication for a significant influence of the calcium phosphate phase or the particle shape (e.g. spherical or rod-like) on the biological response. In summary, the risk associated with an exposition to nanoparticulate calcium phosphate in doses that are usually applied in biomedicine, health care products, and cosmetics is very low and most likely not present at all.

STATEMENT OF SIGNIFICANCE

Calcium phosphate is a well-established biomaterial. However, there are occasions when it occurs in a nanoparticulate form (e.g. as nanoparticle or as nanoparticulate bone substitution material) or after abrasion from a calcium phosphate-coated metal implant. In the light of the current discussion on the safety of nanoparticles, there have been concerns about potential adverse effects of nano-calcium phosphate, e.g. in a statement of a EU study group from 2016 about possible dangers associated with non-spherical nano-hydroxyapatite in cosmetics. In the US, there was a discussion in 2016 about the dangers of nano-calcium phosphate in babyfood. In this review, the potential exposition routes for nano-calcium phosphate are reviewed, with special emphasis on its application as biomaterial.

Recent progress on fabrication and drug delivery applications of nanostructured hydroxyapatite

Through this brief review, we provide a comprehensive historical background of the development of nanostructured hydroxyapatite (nHAp), and its application potentials for controlled drug delivery, drug conjugation, and other biomedical treatments. Aspects associated with efficient utilization of hydroxyapatite (HAp) nanostructures such as their synthesis, interaction with drug molecules, and other concerns, which need to be resolved before they could be used as a potential drug carrier in body system, are discussed. This review focuses on the evolution of perceptions, practices, and accomplishments in providing improved delivery systems for drugs until date. The pioneering developments that have presaged today's fascinating state of the art drug delivery systems based on HAp and HAp-based composite nanostructures are also discussed. Special emphasis has been given to describe the application and effectiveness of modified HAp as drug carrier agent for different diseases such as bone-related disorders, carriers for antibiotics, anti-inflammatory, carcinogenic drugs, medical imaging, and protein delivery agents. As only a very few published works made comprehensive evaluation of HAp nanostructures for drug delivery applications, we try to cover the three major areas: concepts, practices and achievements, and applications, which have been consolidated and patented for their practical usage. The review covers a broad spectrum of nHAp and HAp modified inorganic drug carriers, emphasizing some of their specific aspects those needed to be considered for future drug delivery applications. This article is categorized under: Implantable Materials and Surgical Technologies > Nanomaterials and Implants Therapeutic Approaches and Drug Discovery > Nanomedicine for Respiratory Disease Nanotechnology Approaches to Biology > Cells at the Nanoscale.

Regenerating bone with bioactive glass scaffolds: A review of in vivo studies in bone defect models

Large bone defects resulting from fractures and disease are a medical concern, being often unable to heal spontaneously by the body's repair mechanisms. Bone tissue engineering (BTE) is a promising approach for treating bone defects through providing a template to guide osseous regeneration. 3D scaffolds with microstructure mimicking host bone are necessary in common BTE strategies. Bioactive glasses (BGs) attract researchers' attention as BTE scaffolds as they are osteoconductive and osteoinductive in certain formulations. In vivo animal models allow understanding and evaluation of materials' performance in the complex physiological environment, being an inevitable step before clinical trials. The aim of this paper is to review for the first time published research investigating the in vivo osseous regenerative capacity of 3D BG scaffolds in bone defect animal models, to better understand and evaluate the progress and future outlook of the use of such scaffolds in BTE. The literature analysis reveals that the regenerative capacity of BG scaffolds depends on several factors; including BG composition, fabrication method, scaffold microstructure and pore characteristics, in addition to scaffold pretreatment and whether or not the scaffolds are loaded with growth factors. In addition, animal species selected, defect size and implantation time affect the scaffold in vivo behavior and outcomes. The review of the literature also makes clear the difficulty encountered to compare different types of bioactive glass scaffolds in their bone forming ability. Even considering such limitations of the current state-of-the-art, results generated from animal bone defect models provide an essential source of information to guide the design of BG scaffolds in future.

STATEMENT OF SIGNIFICANCE

Bioactive glasses are at the centre of increasing research efforts in bone tissue engineering as the number of research groups around the world carrying out research on this type of biomaterials continues to increase. However, there are no previous reviews in literature which specifically cover investigations of the performance of bioactive glass scaffolds in bone defect animal models. This is the topic of the present review, in which we have analysed comprehensively all available literature in the field. The review thus fills a gap in the biomaterials literature providing a broad platform of information for researchers interested in bioactive glasses in general and specifically in the outcomes of in vivo models. Bioactive glass scaffolds of different compositions tested in relevant bone defect models are covered.

Comparing the Efficacy of Three Different Nano-scale Bone Substitutes: In vivo Study

Background:

Synthetic biocompatible bone substitutions have been used widely for bone tissue regeneration as they are safe and effective. The aim of this animal study is to compare the effectiveness of three different biocompatible bone substitutes, including nano-hydroxyapatite (nano-HA) nano-bioglass (nano-BG) and forstrite scaffolds.

Materials and Methods:

In this interventional and experimental study, four healthy dogs were anesthetized, and the first to fourth premolars were extracted in each quadrant. After healing, the linear incision on the crestal ridge from molar to anterior segment prepared in each quadrant and 16 defects in each dog were prepared. Nano-HA, nano-BG, and forstrite scaffold was prepared according to the size of defects and placed in the 12 defects randomly, four defects remained as a control group. The dogs were sacrificed in four time intervals (15, 30, 45, and 60 days after) and the percentage of different types of regenerated bones (lamellar and woven) and connective tissue were recorded in histological process. The data were analyzed using Mann–Whitney test (α = 0.05).

Results:

The difference in nano-HA and nano-BG with the control group was significant in three-time intervals regarding the amount of bone formation (P < 0.01). After 15 days, the nano-HA showed the highest amount of woven and lamellar bone regeneration (18.37 ± 1.06 and 30.44 ± 0.54).

Conclusion:

Nano-HA and nano-BG groups showed a significant amount of bone regeneration, especially after 30 days, but paying more surveys and observation to these materials as bone substitutes seem to be needed.

Clinical and Histomorphometric Assessment of Lateral Alveolar Ridge Augmentation Using a Corticocancellous Freeze-Dried Allograft Bone Block

Horizontal ridge augmentation with allografts has attracted notable attention because of its proper success rate and the lack of disadvantages of autografts. Corticocancellous block allografts have not been adequately studied in humans. Therefore, this study clinically and histomorphometrically evaluated the increase in ridge width after horizontal ridge augmentation using corticocancellous block allografts as well as implant success after 12 to 18 months after implantation. In 10 patients receiving implants (3 women, 7 men; mean age = 45 years), defective maxillary alveolar ridges were horizontally augmented using freeze-dried bone allograft blocks. Ridge widths were measured before augmentation, immediately after augmentation, and ∼6 months later in the reentry surgery for implantation. This was done at points 2 mm (A) and 5 mm (B) apically to the crest. Biopsy cores were acquired from the implantation site. Implant success was assessed 15.1 ± 2.7 months after implantation (range = 12-18 months). Data were analyzed using Friedman and Dunn tests (α = 0.05). At point A, ridge widths were 2.77 ± 0.37, 8.02 ± 0.87, and 6.40 ± 0.66 mm, respectively, before surgery, immediately after surgery, and before implantation. At point B, ridge widths were 3.40 ± 0.39, 9.35 ± 1.16, and 7.40 ± 1.10 mm, respectively, before surgery, immediately after surgery, and before implantation. The Friedman test showed significant increases in ridge widths, both at point A and point B (both P = .0000). Postaugmentation resorption was about 1.5-2 mm and was statistically significant at points A and B (P < .05, Dunn). The percentage of newly formed bone, residual graft material, and soft tissue were 33.0% ± 11.35% (95% confidence interval [CI] = 24.88%-41.12%), 37.50% ± 19.04% (95% CI = 23.88%-51.12%), and 29.5%, respectively. The inflammation was limited to grades 1 or zero. Twelve to 18 months after implantation, no implants caused pain or showed exudates or pockets. Radiographic bone loss was 2.0 ± 0.7 mm (range = 1-3). It can be concluded that lateral ridge augmentation with corticocancellous allograft blocks might be successful both clinically and histologically. Implants might have a proper clinical success after a minimum of 12 months.

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.

Clinical and Radiologic Evaluation of Regenerative Potential of NHA Paste and DBM in the Treatment of Periodontal Intra-bony Defects -A Randomized Control Trial

INTRODUCTION

Previous studies have shown that Hydroxyapatite (HA) has shown good results in the treatment of intra-osseous periodontal defects. A newer variety of HA has been designed over a period of research which has nano-sized particles and is availed in a paste consistency called Nanocrystalline Hydroxyapatite paste (NHA paste). This variation in size and surface area of NHA paste can provide better results when used in intra-bony defects.

AIM

The purpose of this study was to compare the clinical and radiographic outcomes obtained with usage of NHA paste to those obtained with Demineralized Bone Matrix (DBM) in the treatment of periodontal intra-bony defects.

MATERIAL AND METHODS

A clinical trial was carried out for a period of 12 months. A total of 26 intra-bony defects in 10 patients were divided into experimental and control sites. The experimental sites were debrided and grafted with NHA paste. The control sites were debrided and grafted with DBM-Xenograft. Probing Depth, Clinical Attachment Level (DCAL) and Gingival Margin (GM) position were recorded at baseline 3, 6, 9 and 12 months. Standardized radiographs were also documented at these recalls. The results were averaged (mean± standard deviation) for each parameter and Student t-test was used to determine intra-group statistical difference and One way analyses of variance (ANOVA) to test the difference between groups using Excel and SPSS (SPSS Inc, Chicago) software packages.

RESULTS

On completion of 12 months, the mean percentage of PD reduction achieved in the experimental and control sites was 67.45% and 69.03% respectively (p<0.05). The mean percentage of gain achieved in CAL was 63.58% and 61.42% in the experimental and control sites respectively (p<0.05). Gingival recession was seen to be non-significant in the experimental and control sites. The mean percentage of bone fill in the control group obtained was 48.16% where as the percentage of bone fill obtained in the experimental group was 48.64% (p<0.05).

CONCLUSION

Overall, both therapies led to significant improvements of the investigated parameters. The NHA paste was as effective in terms of improving clinical and radiographic parameters as DBM-Xenograft, which is an already established bone graft. There is a need for further long term controlled studies evaluating the adjunctive benefits of usage of NHA paste in the treatment of periodontal intra-bony defects.

Clinical efficacy of grafting materials in alveolar ridge augmentation: A systematic review

PURPOSE

To evaluate the efficacy of grafting materials in lateral and vertical ridge augmentations.

MATERIALS AND METHODS

A systematic review of the literature on the clinical use of grafting materials of the years 1995 to April 2015 was conducted using electronic search of PubMed and Cochrane libraries and hand search of eight print journals. A total of 184 papers were included, comprising 6182 patients. Parameters evaluated were observation period [months], bone formation [histologic area%], defect fill [%], horizontal and vertical gain [mm], loss of augmented volume [mm], complication rate [%], and implant survival rate [%]. Results are expressed as weighted means ± SD.

RESULTS

Results were obtained after a weighted mean observation period of 27.4 months (range 3-168 months). Bone formation in the augmented areas varied from 33.2 ± 14.9% for allogeneic grafts to 56.0 ± 25.6% for mixtures of autogenous and other grafting materials. Defect fill in dehiscence defects ranged from 51.0 ± 13.6% (synthetic) to 85.8 ± 13.4% (xenogeneic) for the different materials, with an overall weighted mean of 79.8 ± 18.7%. Weighted mean horizontal gain for all particulate grafting materials was 3.7 ± 1.2 mm, with variation between 2.2 ± 1.2 mm (synthetic) and 4.5 ± 1.0 mm (mixtures of autogenous bone with allogeneic/xenogeneic grafting material) without statistical significance. Weighted overall mean vertical gain was 3.7 ± 1.4 mm. Vertical gain was substantially higher when space-making barrier materials such as titanium meshes were used; however this was also associated with strong increase in complication rate. Block grafts achieved higher horizontal gain by approximately 1 mm. The use of block grafts achieved significantly increased vertical gain compared to particulate material only when autogenous block grafts from extraoral donor sites were used.

CONCLUSION

Horizontal and vertical gain by 3.7 mm on average can be achieved using particulate materials. This can be increased by using titanium meshes. Substantial vertical gains beyond this dimension require the use of extraoral bone block grafts.

Bone formation in mono cortical mandibular critical size defects after augmentation with two synthetic nanostructured and one xenogenous hydroxyapatite bone substitute - in vivo animal study

OBJECTIVES

Healing characteristics as well as level of tissue integration and degradation of two different nanostructured hydroxyapatite bone substitute materials (BSM) in comparison with a deproteinized hydroxyapatite bovine BSM were evaluated in an in vivo animal experiment.

MATERIAL AND METHODS

In the posterior mandible of 18 minipigs, bilateral mono cortical critical size bone defects were created. Randomized augmentation procedures with NanoBone(®) (NHA1), Ostim(®) (NHA2) or Bio-Oss(®) (DBBM) were conducted (each material n = 12). Samples were analyzed after five (each material n = 6) and 8 months (each material n = 6). Defect healing, formation of soft tissue and bone as well as the amount of remaining respective BSM were quantified both macro- and microscopically.

RESULTS

For NHA2, the residual bone defect after 5 weeks was significantly less compared to NHA1 or DBBM. There was no difference in residual BSM between NHA1 and DBBM, but the amount in NHA2 was significantly lower. NHA2 also showed the least amount of soft tissue and the highest amount of new bone after 5 weeks. Eight months after implantation, no significant differences in the amount of residual bone defects, in soft tissue or in bone formation were detected between the groups. Again, NHA2 showed significant less residual material than NHA1 and DBBM.

DISCUSSION

We observed non-significant differences in the biological hard tissue response of NHA1 and DBBM. The water-soluble NHA2 initially induced an increased amount of new bone but was highly compressed which may have a negative effect in less stable augmentations of the jaw.

Clinical and radiographic evaluation of nanocrystalline hydroxyapatite with or without platelet-rich fibrin membrane in the treatment of periodontal intrabony defects

Background:

Nano-sized ceramics may represent a promising class of bone graft substitutes due to their improved osseointegrative properties. Nanocrystalline hydroxyapatite (NcHA) binds to bone and stimulate bone healing by stimulation of osteoblast activity. Platelet-rich fibrin (PRF), an intimate assembly of cytokines, glycan chains, and structural glycoproteins enmeshed within a slowly polymerized fibrin network, has the potential to accelerate soft and hard tissue healing. The present study aims to explore the clinical and radiographical outcome of NcHA bone graft with or without PRF, in the treatment of intrabony periodontal defects.

Materials and Methods:

In a split-mouth study design, 20 patients having two almost identical intrabony defects with clinical probing depth of at least 6 mm were selected for the study. Selected sites were randomly divided into two groups. In Group I, mucoperiosteal flap elevation followed by the placement of NcHA was done. In Group II, mucoperiosteal flap elevation, followed by the placement of NcHA with PRF was done. Clinical and radiographic parameters were recorded at baseline and at 6-month postoperatively.

Results:

Both treatment groups showed a significant probing pocket depth (PPD) reduction, clinical attachment gain, increase bone density 6-month after surgery compared with baseline. However, there was a significantly greater PPD reduction and clinical attachment gain when PRF was added to NcHA.

Conclusion:

The NcHA bone graft in combination with PRF demonstrated clinical advantages beyond that achieved by the NcHA alone.

Effect of nanocrystalline hydroxyapatite socket preservation on orthodontically induced inflammatory root resorption

Objective

Orthodontically induced inflammatory root resorption (OIIRR) is considered to be an important sequel associated with orthodontic tooth movement (OTM). OTM after Socket preservation enhances the periodontal condition before orthodontic space closure. The purpose of this study is to investigate the histologic effects of NanoBone®, a new highly nonsintered porous nano-crystalline hydroxyapatite bone on root resorption following OTM.

Materials and Methods

This experimental study was conducted on four male dogs. In each dog, four defects were created at the mesial aspects of the maxillary and mandibular first premolars. The defects were filled with NanoBone®. We used the NiTi closed coil for mesial movement of the first premolar tooth. When the experimental teeth moved approximately halfway into the defects, after two months, the animals were sacrificed and we harvested the area of interest. The first premolar root and adjacent tissues were histologically evaluated. The three-way ANOVA statistical test was used for comparison.

Results

The mean root resorption in the synthetic bone substitute group was 22.87 ± 11.25×10^-4mm² in the maxilla and 21.41 ± 11.25×10^-4mm² in the mandible. Statistically, there was no significant difference compared to the control group (p>0.05).

Conclusion

The use of a substitution graft in the nano particle has some positive effects in accessing healthy periodontal tissue following orthodontic procedures without significant influence on root resorption (RR). Histological evaluation in the present study showed osteoblastic activity and remodeling environment of nanoparticles in NanoBone®.

Comparing three different three-dimensional scaffolds for bone tissue engineering: an in vivo study

INTRODUCTION

Three-dimensional Scaffold structure of synthetic biomaterials with their interconnected spaces seem to be a safe and effective option in supporting bone regeneration. The aim of this animal study was to compare the effectiveness of three different biocompatible scaffolds: bioglass (BG), demineralized bone matrix (DBM) and forstrite (FR).

MATERIALS AND METHODS

Four healthy dogs were anesthetized and the first to fourth premolars were extracted atraumatically in each quadrant. After healing, linear incision was prepared from molar to anterior segment and 4 defects in each quadrant (16 defects in each dog) were prepared. Scaffold blocks of BG, DBM and FR were resized according to size of defects and placed in the 12 defects randomly, 4 defects remained as control group. The dogs were sacrificed in 4 time intervals (15, 30, 45 and 60 days after) and the percentage of different types of regenerated bones (lamellar and woven) and connective tissue were recorded in histological process. The data were analyzed by one-way ANOVA and post hoc using SPSS software Ver. 15 at significant level of 0.05.

RESULTS

In day 30th, although the amount of regenerated lamellar bone in control, DBM and BG Scaffold (22.37±3.44; 21.46±1.96; 21.21±0.96) were near to each, the FR Scaffold provided the highest amount of lamellar (29.71±7. 94) and woven bone (18.28±2.35). Also, FRS caffold showed significant difference with BG (p=0.026) and DBM Scaffolds (p=0.032) in regenerated lamellar bone.

CONCLUSION

We recommend paying more attention to FR Scaffold as a biomaterial, but it is better to be compared with other nano biomaterials in future studies.

Comparative Study on the Efficacy of Anorganic Bovine Bone (Bio-Oss) and Nanocrystalline Hydroxyapatite (Ostim) in Maxillary Sinus Floor Augmentation

Purpose. The aim of this study was to evaluate the efficacy of anorganic bovine bone (Bio-Oss) in comparison with nanocrystalline hydroxyapatite (Ostim) in sinus floor augmentation. Methods. Ten patients aged 40–80 were selected. All the patients needed sinus floor augmentation due to insufficient bone for simultaneous implant placement. The patients underwent panoramic radiography and cone beam computed tomography (CBCT) prior to surgical procedure. After lifting the sinus membrane, Bio-Oss and Ostim are randomly grafted at one of the two sides. Biopsies were obtained from areas identified 5 months after the surgery and before implant placement and then were prepared for histological analysis. Statistical analysis was performed with nonparametric Wilcoxon signed-rank test for comparison of histological and radiological parameters between the two groups. Results. Histological findings revealed a significant increase in percentages of new bone in the Ostim group (P = 0.015). Furthermore, new bone density was greater with Ostim compared to Bio-Oss (P = 0.038); however, the difference in height increase after surgery did not reach statistical significance (P = 0.191). Conclusion. Despite the limitations of this trial, Ostim and Bio-Oss are useful biomaterials in sinus augmentation and Ostim seems to be even more effective in new bone formation.

Comparison of Nano-Sized Hydroxyapatite and β-Tricalcium Phosphate in the Treatment of Human Periodontal Intrabony Defects

BACKGROUND

Since the advent of nanotechnology, various materials have been introduced for the treatment of the bone defects which have shown promising results.

AIM

The purpose of this study was to compare the effect of nano-sized Hydroxyapatite (NHA) and β-Tricalcium Phosphate (β-TCP) in the treatment of human periodontal defects.

MATERIALS AND METHODS

Tweleve patients with a total of 24 sites which were almost identical as determined clinically and radiographically were selected for the study. The selected sites were treated with access flap surgery were divided into two groups: Group I was treated with NHA and Group II treated with β-TCP. Following clinical and radiographic parameters were recorded at baseline, 3 months and 6 months post operatively: 1) Probing pocket depth (PPD); 2)Clinical attachment level (CAL); 3) Gingival recession (GR); 4) Radiographic Defect Depth.

RESULTS

Groups showed statistically significant improvements in soft and hard tissue parameters after 3 months and 6 months. Greater reduction in PPD, gain in CAL and Radiographic Defect Fill (RDF) was seen in Group I after three months whereas after six months were no statistically significant difference was seen with regard to soft and hard tissue measurements.

CONCLUSION

Within limits of the study, both NHA and β-TCP have proved to be beneficial in the management of periodontal defects. Treatment of intrabony periodontal defects with NHA leads to significant improvement in early clinical and radiographic outcomes as compared to β-TCP.

Evaluation of horizontal ridge augmentation using beta tricalcium phosphate and demineralized bone matrix: A comparative study

Objectives: To evaluate the effectiveness of beta tricalcium phosphate (β-TCP) alone compared to β-TCP and Demineralized Bone Matrix (DBM) in regenerating localized horizontal maxillary alveolar ridge deficiencies prior to implant placement. Study Design: The study included 20 patients with horizontal maxillary ridge deficiencies limited to one or more neighbouring teeth and initial ridge width of ≤ 5mmm. Patients were divided equally into two equal groups. Ridge augmentation was performed using Guided Bone Regeneration (GBR) principals. In group I GBR was performed using β-TCP only, while in group II both β-TCP and DBM were used. Following a 6 months healing period, bone cores from both groups were retrieved and implants were inserted. Specimens were examined histologically to calculate percentage of mineralized bone. Apical and crestal changes in ridge dimensions were calculated by digital subtraction using Cone Beam Computed Tomography (CBCT) immediately after graft placement and six months later. Results: There was a statistically significant difference between the mean area percentage of mineralized bone between both groups where it was 40.1 % (range: 27.76-% 66.29 %) for group I and 68.96 % (range: 60.07 % - 87.33 %) for group II. Radiograpically, the mean ridge width in group I increased crestally to 4.66 mm (range:3.5-5mm) and apically to 6.12 mm (range: 4.1-6.7 mm). In group II the mean ridge width increased crestally to 5.2 mm (range 4.9-5.4mm) and apically to 6.9 mm (range 6.0-7.8 mm). Group II showed more bone gain with a mean of 1.37 mm crestally and 2.44 mm apically. This difference however was not statistically significant Conclusion: Within the limitations of this study the combination of DBM and β-TCP can be used effectively in cases exhibiting minimal alveolar ridge defects.

Key words:Guided bone regeneration, equine bone, alloplast, bone graft.

Bioerodible calcium sulfate/poly(β-amino ester) hydrogel composites

The capacity to quickly regenerate or augment bone lost as a result of resorption is crucial to ensure suitable application of prosthetics for restoring masticatory function. Calcium sulfate hemihydrate (CS)-based bone graft substitute composites containing poly(β-amino ester) (PBAE) biodegradable hydrogel particles were developed to act as a 'tenting' barrier to soft tissue infiltration, potentially providing adequate space to enable vertical bone regeneration. CS has long been recognized as an osteoconductive biomaterial with an excellent reputation as a biocompatible substance. Composite samples were fabricated with varying amounts (1 or 10 wt%) and sizes (53-150 or 150-250 μm) of gel particles embedded in CS. The swelling and degradation rates of PBAE gels alone were rapid, resulting in complete degradation in less than 24h, an important characteristic to aid in controlled release of drug. MicroCT images revealed a homogeneous distribution of gel particles within the CS matrix. All CS samples degraded via surface erosion, with the amount of gel particles (i.e., 10 wt% gel particles) having only a small, but significant, effect on the dissolution rate (4% vs. 5% per day). Compression testing determined that the amount, but not the size, of gel particles had a significant effect on the overall strength of the composites. As much as a 75% drop in strength was seen with a 10 wt% loading of particles. A pilot study using PBAE particles loaded with the multipotential drug curcumin demonstrated sustained release of drug from CS composites. By adjusting the amount and/or size of the biodegradable gel particles embedded in CS, mechanical strength and degradation rates of the composites, as well as the drug release kinetics, can be tuned to fabricate, multi-functional 'space-making' bone grafting substitutes.

Synthesis methods for nanosized hydroxyapatite with diverse structures

Hydroxyapatite (HAp) is the major mineral constituent of vertebrate bones and teeth. It has been well documented that HAp nanoparticles can significantly increase the biocompatibility and bioactivity of man-made biomaterials. Over the past decade, HAp nanoparticles have therefore increasingly been in demand, and extensive efforts have been devoted to develop many synthetic routes, involving both scientifically and economically new features. Several investigations have also been made to determine how critical properties of HAp can be effectively controlled by varying the processing parameters. With such a wide variety of methods for the preparation of HAp nanoparticles, choosing a specific procedure to synthesize a well-defined powder can be laborious; accordingly, in the present review, we have summarized all the available information on the preparation methodologies of HAp, and highlighted the inherent advantages and disadvantages involved in each method. This article is focused on nanosized HAp, although recent articles on microsized particles, especially those assembled from nanoparticles and/or nanocrystals, have also been reviewed for comparison. We have also provided several scientific figures and discussed a number of critical issues and challenges which require further research and development.

Immunohistochemical analysis of staged guided bone regeneration and osseointegration of titanium implants using a polyethylene glycol membrane

OBJECTIVES

This study aimed to immunohistochemically evaluate staged guided bone regeneration and osseointegration of titanium implants using two bone graft substitutes in combination with a polyethylene glycol (PEG) membrane in a dog model.

MATERIALS AND METHODS

Saddle-type alveolar ridge defects were prepared in the lower jaws of 12 foxhounds and randomly filled with a natural bone mineral (NBM) or a biphasic calcium phosphate (SBC) and covered with an in situ gelling PEG membrane. After a healing period of 8 and 12 weeks (six animals each), modSLA titanium implants were inserted to heal in a submerged position. At 8 + 2 and 12 + 2 weeks, respectively, dissected blocks were processed for immunohistochemical analysis [osteocalcin (OC)].

RESULTS

After 8 + 2 weeks, mean OC values (%) tended to be higher in the NBM group (NBM, 32.7 ± 8.9%), but failed to reach statistical significance over the SBC group (SBC, 24.4 ± 6.6%). After 12 + 2 weeks, mean OC values decreased in both groups and was almost identical in both groups (NBM 1.6 ± 1.2%/SBC 2.1 ± 1.4%).

CONCLUSION

It was concluded that all augmentation procedures investigated were characterised by a comparable OC activity during the process of bone regeneration and osseointegration of modSLA titanium implants.

Nano-crystalline hydroxyapatite bone graft combined with bioresorbable collagen membrane in the treatment of periodontal intrabony defects: A randomized controlled clinical trial

Aim:

To evaluate the clinical outcome of nanocrystalline hydroxyapatite (NcHA) bonegraft (Sybograf^®) in combination with collagen membrane (PerioCol^®) compared with open flap debridement (OFD) only in the treatment of intrabony periodontal defects.

Materials and Methods:

Eighteen intrabony defects in 16 systemically healthy patients aged between 25-65 years, were randomly assigned to test and control groups. The Plaque index, gingival index, probing pocket depth (PPD), clinical attachment level (CAL), and gingival recession were recorded at baseline, and were reevaluated at 6 months. In addition to this, radiographic bone fill was assessed using digital software. At the test site NcHA bone graft and collagen membrane was placed, whereas at the control site only, OFD was done. Recall appointments were made at 7^th day, 1^st month, 3^rd month, and 6^th month.

Results:

The data were subjected to statistical analysis using the Mann-Whitney ‘U’ Test and Wilcoxon signed rank sum test. In the control group, the mean reduction of PPD was 3.22±1.09 mm and CAL gain was 2.78±1.09 mm. In the test group, the mean PPD reduction of 4.33±0.5 mm and mean gain in CAL was 3.78±0.66 mm at 6 months. The mean increase in gingival recession was 0.55±0.72 mm in test and 0.44±0.52 mm in control group.

Conclusion:

The NcHA bone graft in combination with collagen membrane demonstrated better clinical outcomes compared with OFD alone.

Rehabilitation of deficient alveolar ridges using titanium grids before and simultaneously with implant placement: a systematic review

BACKGROUND

The aim of the present study is to perform a systematic review of the literature on the use of titanium grids for implant surgery before and simultaneously with implant placement and to assess the success rate of the procedure, as well as survival and success rates of implants placed in the regenerated areas.

METHODS

Medline was used to identify studies in English published from 1996 to 2011. An additional hand search was performed of the relevant journals and of the bibliographies of the papers identified. Articles retrieved by two independent authors were screened using specific inclusion criteria: randomized controlled trials (RCTs), controlled clinical trials, and prospective clinical studies regarding vertical and/or horizontal regeneration of the alveolar ridge using titanium grids, in association or not with biomaterials, before and simultaneously with implant placement.

RESULTS

Six articles were selected, including a total of 79 patients, 87 titanium grids, and 141 implants. Twenty-four implants were placed simultaneously with titanium grids, and 117 implants were inserted after a period of 4 to 9 months. Titanium grids in combination with autogenous bone were used in 43 cases, 25 in combination with a mixture of autogenous bone and bone substitutes, 14 in association with bone substitutes, five using only titanium grids. The overall success rate of the regenerative procedures was 98.86%; the overall survival and success rates of implants were 100% and 93.2%, respectively.

CONCLUSIONS

The main limit of the present systematic review is the scarcity of papers with an adequate and consistent methodology regarding the data collection and analysis and the lack of RCTs and large well-designed long-term trials. Survival and success rates of implants placed in the areas treated with titanium grids were comparable to those of implants placed in native, non-regenerated bone and of implants placed in bone regenerated with resorbable and non-resorbable membranes.

Clinical and radiographic evaluation of Nano-crystalline hydroxyapatite bone graft (Sybograf) in combination with bioresorbable collagen membrane (Periocol) in periodontal intrabony defects

Background:

Nanosized ceramics may represent a promising class of bone graft substitutes due to their improved osseointegrative properties. Nanocrystalline Hydroxyapatite (NcHA) bind to bone and stimulate bone healing by stimulation of osteoblast activity. The present study aims to explore the clinical and radiographical outcome of NcHA bonegraft (Sybograf^®) with collagen membrane (Periocol^®), in comparison with open flap debridement (OFD), in the treatment of intrabony periodontal defects.

Materials and Methods:

A parallel-group, randomized, controlled clinical trial was designed to conduct the study. Eighteen intrabony defects in 14 systemically healthy patients aged between 25 to 65 years were randomly assigned to test and control group. The plaque index, gingival index, probing pocket depth (PPD), clinical attachment level (CAL), and gingival recession (REC) were recorded at baseline, and were reevaluated at 6 months. In addition to this, radiographic bone fill was assessed using digital software. At the test site, NcHA bone graft and collagen membrane was placed, whereas at the control site, only OFD was done. Recall appointments were made at 7 days, 30 days, and then at 3 months and 6 months.

Results:

The data were subjected to statistical analysis using the Mann-Whitney ‘U’ Test and Wilcoxon signed rank sum test. In the control group, the mean reduction of PPD was 3.22±1.09 mm (P=0.007) and CAL gain was 2.77±1.09 mm (P=0.007). In the test group, the mean PPD reduction of 4.33±0.5 mm (P=0.006) and mean gain in CAL was 3.77±0.66 mm (P=0.006) at 6 months. The mean increase in REC was 0.55±0.72 mm (P=0.025) in test, and 0.44±0.52 mm (P=0.046) in control group. The mean gain in radiographic defect fill was 2.07±0.67 mm (P=0.008) in test and 0.91±0.21 mm (P=0.007) in control group.

Conclusion:

The nanocrystalline hydroxyapatite bone graft in combination with collagen membrane demonstrated clinical advantages beyond that achieved by OFD alone.

Clinical-radiographic and histological evaluation of two hydroxyapatites in human extraction sockets: a pilot study

After tooth extraction the healing process involves bone resorption and soft tissue contraction, events that can compromise the ideal implant placement with functional and aesthetic limitations. Following tooth extraction, a socket preservation technique can limit bone resorption. This study evaluated two different types of hydroxyapatite (HA) grafting materials placed into fresh extraction sockets, 6 months after tooth extraction, histologically, clinically and radiographically. Ten extraction sockets from 10 patients were divided in two groups: 5 sockets received a biomimetic HA and 5 received nanocrystalline HA. After 6 months, before implant placement, samples from the grafted area were harvested and evaluated clinically, radiographically and histologically. The percentages of bone, osteoid areas and residual material in the two groups were not statistically different. All samples showed great variability with extensive bone formation and total material resorption or amounts of osteoid tissue that filled the spaces between the residual material particles. The authors did not find any differences between biomimetic and nanocrystalline HA and assume that, within the limits of this study, both these materials could be applied into fresh extraction sockets to limit bone resorption. A control material and a much larger sample size are needed to confirm these findings.

No effect of dynamic loading on bone graft healing in femoral segmental defect reconstructions in the goat

We studied if a static or dynamic mode of nail fixation influenced the healing of segmental defect reconstructions in long bones. Defects in the femur of goats were reconstructed using a cage filled with firmly impacted morsellised allograft mixed with a hydroxyapatite paste (Ostim). All reconstructions were stabilised with an intramedullary nail. In one group (n=6) the intramedullary nail was statically locked, in the second group (n=6) a dynamic mode of nail fixation was applied. We hypothesised that dynamisation of the nail would load, and by that stimulate the healing of the bone graft. Mechanical torsion strength of the reconstructions of the femur with the static and dynamic mode of nail fixation appeared to be 74.8±17.5% and 73.0±13.4%, respectively as compared with the contralateral femurs after 6 months. In all reconstructions, the grafts united radiographically and histologically to the host bone, and remodelled into a new vital bone structure. No large differences were found between newly formed bone areas inside and outside the mesh of the two groups. The area of callus outside the mesh in the dynamic mode of fixation group was smaller (p=0.042), whilst the percentage of bone outside the mesh was larger (p=0.049), as compared to the static mode of fixation group. The data suggest that healing of these defects with impacted morsellised graft in a cage is not significantly influenced by the mode of fixation of the nail in this model.

Evaluation of a novel nanocrystalline hydroxyapatite paste Ostim in comparison to Alpha-BSM - more bone ingrowth inside the implanted material with Ostim compared to Alpha BSM

Background

The purpose of this study was to evaluate the performance a newly developed nanocrystalline hydroxyapatite, OSTIM^® following functional implantation in femoral sites in thirty-eight sheep for 1, 2 or 3 months. Ostim^® 35 was compared to an established calcium phosphate, Alpha BSM^®.

Methods

Biomechanical testing, μ-CT analysis, histological and histomorphological analyses were conducted to compare the treatments including evaluation of bone regeneration level, material degradation, implant biomechanical characteristics.

Results

The micro-computed tomography (μCT) analysis and macroscopic observations showed that Ostim^® seemed to diffuse easily particularly when the defects were created in a cancellous bone area. Alpha BSM^® remained in the defect.

The performance of Ostim was good in terms of mechanical properties that were similar to Alpha BSM^® and the histological analysis showed that the bone regeneration was better with Ostim^® than with Alpha BSM^®. The histomorphometric analysis confirmed the qualitative analysis and showed more bone ingrowth inside the implanted material with Ostim^® when compared to Alpha BSM ^® at all time points.

Conclusions

The successful bone healing with osseous consolidation verifies the importance of the nanocrystalline hydroxyapatite in the treatment of metaphyseal osseous volume defects in the metaphyseal spongiosa.

Nanodimensional and Nanocrystalline Apatites and Other Calcium Orthophosphates in Biomedical Engineering, Biology and Medicine

Recent developments in biomineralization have already demonstrated that nanosized particles play an important role in the formation of hard tissues of animals. Namely, the basic inorganic building blocks of bones and teeth of mammals are nanodimensional and nanocrystalline calcium orthophosphates (in the form of apatites) of a biological origin. In mammals, tens to hundreds nanocrystals of a biological apatite were found to be combined into self-assembled structures under the control of various bioorganic matrixes. In addition, the structures of both dental enamel and bones could be mimicked by an oriented aggregation of nanosized calcium orthophosphates, determined by the biomolecules. The application and prospective use of nanodimensional and nanocrystalline calcium orthophosphates for a clinical repair of damaged bones and teeth are also known. For example, a greater viability and a better proliferation of various types of cells were detected on smaller crystals of calcium orthophosphates. Thus, the nanodimensional and nanocrystalline forms of calcium orthophosphates have a great potential to revolutionize the field of hard tissue engineering starting from bone repair and augmentation to the controlled drug delivery devices. This paper reviews current state of knowledge and recent developments of this subject starting from the synthesis and characterization to biomedical and clinical applications. More to the point, this review provides possible directions of future research and development.

Magnesium-enriched hydroxyapatite compared to calcium sulfate in the healing of human extraction sockets: radiographic and histomorphometric evaluation at 3 months

BACKGROUND

Reduction of alveolar height and width after tooth extraction may present problems for implant placement, especially in the anterior maxilla where bone volume is important for biologic and esthetic reasons. Different graft materials have been proposed to minimize the reduction in ridge volume. The aim of this study was to compare radiographic and histomorphometric results of magnesium-enriched hydroxyapatite (MHA) and calcium sulfate (CS) grafts in fresh sockets after tooth extractions.

METHODS

Forty-five fresh extraction sockets with three bone walls were selected in 15 patients. A split-mouth design was used: 15 sockets on the right side of the jaw received MHA, 15 sockets on the left side received CS, and 15 random unfilled sockets were considered the control (C) group. Intraoral digital radiographs were taken at baseline and at 3 months after graft material placement. At 3 months, cylinder bone samples were obtained for histology and histomorphometry analysis.

RESULTS

The difference in mean radiographic vertical bone level from baseline to 3 months was -2.48 +/- 0.65 mm in the CS group, -0.48 +/- 0.21 mm in the MHA group, and -3.75 +/- 0.63 mm in the unfilled C group. Statistically significant differences (P <0.05) were found between CS and MHA groups and between MHA and C groups. Histologic examination revealed bone formation in all treated sites; trabecular bone assessment did not differ among apical, mesial, and coronal portions of the specimens. Mean vital bone measurements for CS, MHA, and C groups were 45.0% +/- 6.5%, 40.0% +/- 2.7%, and 32.8% +/- 5.8%, respectively. Statistically significant differences (P <0.05) were found among all groups. Connective tissue percentages averaged 41.5% +/- 6.7% for the CS group, 41.3% +/- 1.3% for the MHA group, and 64.6% +/- 6.8% for the C group. Statistically significant differences (P <0.05) were found between CS and C groups and between MHA and C groups. The CS-grafted sockets showed 13.9% +/- 3.4% residual implant material, whereas the MHA-treated sockets showed 20.2% +/- 3.2% residual material. The difference between the groups was statistically significant (P <0.05).

CONCLUSIONS

Radiographs revealed a greater reduction of alveolar ridge in the CS group than in the MHA group. Histologic examination showed more bone formation and faster resorption in the CS group and more residual implant material in the MHA group.