A Veterans Administration Cooperative Study of biphasic calcium phosphate ceramic in periodontal osseous defects

3D printing technology and its combination with nanotechnology in bone tissue engineering

With the graying of the world's population, the morbidity of age-related chronic degenerative bone diseases, such as osteoporosis and osteoarthritis, is increasing yearly, leading to an increased risk of bone defects, while current treatment methods face many problems, such as shortage of grafts and an incomplete repair. Therefore, bone tissue engineering offers an alternative solution for regenerating and repairing bone tissues by constructing bioactive scaffolds with porous structures that provide mechanical support to damaged bone tissue while promoting angiogenesis and cell adhesion, proliferation, and activity. 3D printing technology has become the primary scaffold manufacturing method due to its ability to precisely control the internal pore structure and complex spatial shape of bone scaffolds. In contrast, the fast development of nanotechnology has provided more possibilities for the internal structure and biological function of scaffolds. This review focuses on the application of 3D printing technology in bone tissue engineering and nanotechnology in the field of bone tissue regeneration and repair, and explores the prospects for the integration of the two technologies.

Engineering periodontal tissue interfaces using multiphasic scaffolds and membranes for guided bone and tissue regeneration

Periodontal diseases are one of the greatest healthcare burdens worldwide. The periodontal tissue compartment is an anatomical tissue interface formed from the periodontal ligament, gingiva, cementum, and bone. This multifaceted composition makes tissue engineering strategies challenging to develop due to the interface of hard and soft tissues requiring multiphase scaffolds to recreate the native tissue architecture. Multilayer constructs can better mimic tissue interfaces due to the individually tuneable layers. They have different characteristics in each layer, with modulation of mechanical properties, material type, porosity, pore size, morphology, degradation properties, and drug-releasing profile all possible. The greatest challenge of multilayer constructs is to mechanically integrate consecutive layers to avoid delamination, especially when using multiple manufacturing processes. Here, we review the development of multilayer scaffolds that aim to recapitulate native periodontal tissue interfaces in terms of physical, chemical, and biological characteristics. Important properties of multiphasic biodegradable scaffolds are highlighted and summarised, with design requirements, biomaterials, and fabrication methods, as well as post-treatment and drug/growth factor incorporation discussed.

Carrier systems for bone morphogenetic proteins: An overview of biomaterials used for dentoalveolar and maxillofacial bone regeneration

Different types of biomaterials have been used to fabricate carriers to deliver bone morphogenetic proteins (BMPs) in both dentoalveolar and maxillofacial bone regeneration procedures. Despite that absorbable collagen sponge (ACS) is considered the gold standard for BMP delivery, there is still some concerns regarding its use mainly due to its poor mechanical properties. To overcome this, novel systems are being developed, however, due to the wide variety of biomaterial combination, the heterogeneous assessment of newly formed tissue, and the intended clinical applications, there is still no consensus regarding which is more efficient in a particular clinical scenario. The combination of two or more biomaterials in different topological configurations has allowed specific controlled-release patterns for BMPs, improving their biological and mechanical properties compared with classical single-material carriers. However, more basic research is needed. Since the BMPs can be used in multiple clinical scenarios having different biological and mechanical needs, novel carriers should be developed in a context-specific manner. Thus, the purpose of this review is to gather current knowledge about biomaterials used to fabricate delivery systems for BMPs in both dentoalveolar and maxillofacial contexts. Aspects related with the biological, physical and mechanical characteristics of each biomaterial are also presented and discussed.

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Strategies for bone formation and regeneration are a major concern in dentistry.

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Topical delivery of bone morphogenetic proteins (BMPs) allows rapid bone formation.

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BMPs requires proper carrier system to allow controlled and sustained release.

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Carrier should also fulfill mechanical requirements of bone defect sites.

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By using complex composites, it would be possible to develop new carriers for BMPs.

Biphasic Calcium Phosphate Versus Demineralized Freeze-Dried Bone Allograft in the Treatment of Periodontal Disease: A Clinical and Radiographical Evaluation

 Aim

The study aimed to clinically and radiographically evaluate the effect of biphasic calcium phosphate (BCP) versus demineralized freeze-dried bone allograft (DFDBA) in treating periodontal disease.

Method

The study consisted of 44 patients. The sites were randomly assigned to receive one of two treatment modalities (BCP at site 1 and demineralized freeze-dried bone at site 2) by a computerized method. All the clinical data were measured with the help of a University of North Carolina-15 (UNC-15) probe at the baseline, three months, and six months postoperatively. Radiovisiographs were taken using a Rinn XCP® (Dentsply/Rinn Corp, Elgin, IL) system and an oral grid using the paralleling technique. A manual calculation of the defect area was undertaken at the end of six months and was compared with the other groups.

Result

The linear bone growth recorded for site 1 at the end of six months was 3.8 ± 1.14 mm, and site 2 was 4.6 ± 1.07 mm. The intergroup comparison showed more remarkable linear bone growth in site 2, which was statistically insignificant, with a mean difference of 0.8 ± 1.23 mm and a p-value of 0.07.

Conclusion

Improvements were observed on all the documented parameters. However, the sites treated with DFDBA showed better periodontal regeneration.

Evaluation of biphasic hydroxapatite and β-tricalcium phosphate as a bone graft material in the treatment of periodontal vertical bony defects - A clinical and digital radiological measurement study

AIMS AND OBJECTIVE

The present study aimed to evaluate 2 bone graft materials, that is, biphasic hydroxyapatite and β-tricalcium phosphate, in the treatment of periodontal vertical bony defects. In term of attachment level, probing depth and radiographic bone level changes. Also, a new digital method of radiographic assessment was used for measurement of vertical bone defect.

MATERIAL AND METHODS

Ten subjects with periodontitis and having two or more vertical bony defects were enrolled in the study. Patients were classified randomly into 2 groups. Group I consisted of the experimental site where defect was filled with biphasic hydroxyapatite and β-tricalcium phosphate graft and Group II consisted of control site where only the open flap debridement (OFD) was carried out. Clinical parameters were evaluated at baseline, 3 and 6 months; Radiographs were taken at baseline and 6 months after surgery.

RESULTS

Overall, by the end of 6 months, biphasic hydroxyapatite and β-tricalcium phosphate and OFD treatment groups exhibited a significant reduction in probing depth almost by 75% and gain in clinical attachment level at follow-up. In the biphasic hydroxyapatite and β-tricalcium phosphate group, radiographic bone level gain appeared to be greater than in the OFD group.

CONCLUSION

In the present study, biphasic hydroxyapatite and β-tricalcium phosphate have shown promising results and have showed reduction in probing depth, a resolution of osseous defects and gain in clinical attachment level when compared to open flap debridement.

Applying extrusion-based 3D printing technique accelerates fabricating complex biphasic calcium phosphate-based scaffolds for bone tissue regeneration

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Biphasic calcium phosphates offer a chemically similar biomaterial to the natural bone, which can significantly accelerate bone formation and reconstruction.

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Robocasting is a suitable technique to produce porous scaffolds supporting cell viability, proliferation, and differentiation.

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This review discusses materials and methods utilized for BCP robocasting, considering recent advancements and existing challenges in using additives for bioink preparation.

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Commercialization and marketing approach, in-vitro and in-vivo evaluations, biologic responses, and post-processing steps are also investigated.

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Possible strategies and opportunities for the use of BCP toward injured bone regeneration along with clinical applications are discussed.

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The study proposes that BCP possesses an acceptable level of bone substituting, considering its challenges and struggles.

Background

Aim of review

Key scientific concepts of review

Tissue Level Changes after Maxillary Sinus Floor Elevation with Three Types of Calcium Phosphate Ceramics: A Radiological Study with a 5-Year Follow-Up

This study evaluates the radiological changes in tissue height after maxillary sinus floor elevation (MSFE) using three types of calcium phosphate ceramics over a period of up to 5 years after dental implant placement. In 163 patients, MSFE was performed. Three groups of patients were distinguished and treated based on the type of calcium phosphate ceramic used and radiologically evaluated: 40 patients with β-tricalcium phosphate (β-TCP), 76 patients with biphasic calcium phosphate (BCP) 20% hydroxyapatite (HA)-80% β-TCP, and 47 patients with BCP 60% HA-40% β-TCP. Radiological measurements were performed on panoramic radiographs at several time points up to 5 years after dental implant placement. After MSFE, a slow decrease in tissue height measured over time was seen in all three study groups. Resorption of the grafted bone substitutes was more prominent in β-TCP than in BCP ceramics with an HA component (60/40 and 20/80). Loss of tissue height after 5 years was lowest in BCP 60/40 and highest in β-TCP. This radiological study shows a predictable and comparable behavior of the slow decrease in tissue height over time for all three types of calcium phosphate ceramics used in MSFE. The fraction of HA in calcium phosphate ceramics and dental implant loading seems to be beneficial for tissue height maintenance after MSFE.

Biofunctionalization with a TGFβ-1 Inhibitor Peptide in the Osseointegration of Synthetic Bone Grafts: An In Vivo Study in Beagle Dogs

Objectives: The aim of this research was to determine the osseointegration of two presentations of biphasic calcium phosphate (BCP) biomaterial—one untreated and another submitted to biofunctionalization with a TGF-β1 inhibitor peptide, P144, on dental alveolus. Materials and Methods: A synthetic bone graft was used, namely, (i) Maxresorb^® (Botiss Klockner) (n = 12), and (ii) Maxresorb^® (Botiss Klockner) biofunctionalized with P144 peptide (n = 12). Both bone grafts were implanted in the two hemimandibles of six beagle dogs in the same surgical time, immediately after tooth extraction. Two dogs were sacrificed 2, 4, and 8 weeks post implant insertion, respectively. The samples were submitted to histomorphometrical and histological analyses. For each sample, we quantified the new bone growth and the new bone formed around the biomaterial’s granules. After optical microscopic histological evaluation, selected samples were studied using backscattered scanning electron microscopy (BS-SEM). Results: The biofunctionalization of the biomaterial’s granules maintains a stable membranous bone formation throughout the experiment timeline, benefitting from the constant presence of vascular structures in the alveolar space, in a more active manner that in the control samples. Better results in the experimental groups were proven both by quantitative and qualitative analysis. Conclusions: Synthetic bone graft biofunctionalization results in slightly better quantitative parameters of the implant’s osseointegration. The qualitative histological and ultramicroscopic analysis shows that biofunctionalization may shorten the healing period of dental biomaterials.

Effect of water glass coating of tricalcium phosphate on in vitro cellular proliferation and osteogenic differentiation

Background

In this study, the properties of the water glass (WG, sodium-silicate glass) were utilized to control the biodegradability of the beta tricalcium phosphate materials by the WG coating on the tricalcium phosphate disc surface with various coating thickness, chemistry, and heat-treatment.

Methods

Four types of disc specimens were prepared. A sample group A consisted of pure hydroxyapatite (HA) as a negative resorption control; a sample group B consisted of pure beta tricalcium phosphate as a positive resorption control; a sample group C consisted of beta tricalcium phosphate coated with WG as an early resorption model; and a sample group D consisted beta tricalcium phosphate coated with WG and heat-treated at 500°C as a delayed resorption model. Using human bone marrow–derived mesenchymal stem cells, for the analysis of cellular attachment and proliferative activity, 4–6-Diamidino-2-Phenylindole fluorescence technique was used. For the analysis of osteteogenic differentiation, alkaline phospastase (ALP) activity was measured.

Results

The mean z-scores of four groups (A, B, C, and D) in cellular attachment at 4 h after seeding were −1.21, −0.15, 0.42, and 0.94, respectively, and statistically significantly different in all groups respectively. Seven days after seeding, the mean z-scores of cellular proliferation were 1.97, 0.71, 1.48, and 1.83 in the four groups, respectively. The mean z-scores of the ALP activity per the mean z-scores of cell numbers of respective groups on the seventh day were 0.40, −1.51, 0.12, and 0.06, respectively, in four groups.

Conclusion

Initial cellular attachment is better on beta tricalcium phosphate than on HA and is enhanced by WG coating, especially with sintering at the high temperature. Cellular proliferation is considered to be increased by maintaining its attachment site through reduced dissolution of beta tricalcium phosphate by WG coating. Osteogenic differentiation in in-vitro study on the WG-coated beta tricalcium phosphate is thought to be as the result of increased silicon ion release from the WG.

The use of a biphasic calcium phosphate in a maxillary sinus floor elevation procedure: a clinical, radiological, histological, and histomorphometric evaluation with 9- and 12-month healing times

Background

This study evaluates the clinical, radiological, histological, and histomorphometric aspects of a fully synthetic biphasic calcium phosphate (BCP) (60% hydroxyapatite and 40% ß-tricalcium phosphate), used in a human maxillary sinus floor elevation (MSFE) procedure with 9- and 12-month healing time.

Methods

A unilateral MSFE procedure, using 100% BCP, was performed in two series of five patients with healing times of 9 and 12 months respectively. Clinical and radiological parameters were measured up to 5 years postoperatively. Biopsy retrieval was carried out during dental implants placement. Histology and histomorphometry were performed on 5-μm sections of undecalcified bone biopsies.

Results

The MSFE procedure with BCP showed uneventful healing in all cases. All dental implants appeared to be well osseointegrated after 3 months. Radiological evaluation showed less than 1 mm tissue height loss from MSFE to the 5-year follow-up examination. No signs of inflammation were detected on histological examination. Newly formed mineralized tissue was found cranially from the native bone. The BCP particles were surrounded by connective tissue, osteoid islands, and newly formed bone. Mineralized bone tissue was in intimate contact with the BCP particles. After 12 months, remnants of BCP were still present. The newly formed bone had a trabecular structure. Bone maturation was demonstrated by the presence of lamellar bone. Histomorphometric analysis showed at 9 and 12 months respectively an average vital bone volume/total volume of 35.2 and 28.2%, bone surface/total volume of 4.2 mm²/mm³ and 8.3 mm²/mm³, trabecular thickness of 224.7 and 66.7 μm, osteoid volume/bone volume of 8.8 and 3.4%, osteoid surface/bone surface (OS/BS) of 42.4 and 8.2%, and osteoid thickness of 93.9 and 13.6 μm.

Conclusions

MFSE with BCP resulted in new bone formation within the augmented sinus floor and allowed the osseointegration of dental implants in both groups. From a histological and histomorphometric perspective, a 9-month healing time for this type of BCP may be the optimal time for placement of dental implants.

Biphasic calcium phosphate ceramics for bone reconstruction: A review of biological response

Autologous bone graft is considered as the gold standard in bone reconstructive surgery. However, the quantity of bone available is limited and the harvesting procedure requires a second surgical site resulting in severe complications. Due to these limits, scientists and clinicians have considered alternatives to autologous bone graft. Calcium phosphates (CaPs) biomaterials including biphasic calcium phosphate (BCP) ceramics have proven efficacy in numerous clinical indications. Their specific physico-chemical properties (HA/TCP ratio, dual porosity and subsequent interconnected architecture) control (regulate/condition) the progressive resorption and the bone substitution process. By describing the most significant biological responses reported in the last 30years, we review the main events that made their clinical success. We also discuss about their exciting future applications as osteoconductive scaffold for delivering various bioactive molecules or bone cells in bone tissue engineering and regenerative medicine.

STATEMENT OF SIGNIFICANCE

Nowadays, BCPs are definitely considered as the gold standard of bone substitutes in bone reconstructive surgery. Among the numerous clinical studies in literature demonstrating the performance of BCP, Passuti et al. and Randsford et al. studies largely contributed to the emergence of the BCPs. It could be interesting to come back to the main events that made their success and could explain their large adhesion from scientists to clinicians. This paper aims to review the most significant biological responses reported in the last 30years, of these BCP-based materials. We also discuss about their exciting future applications as osteoconductive scaffold for delivering various bioactive molecules or bone cells in bone tissue engineering and regenerative medicine.

3D-Printed Scaffolds and Biomaterials: Review of Alveolar Bone Augmentation and Periodontal Regeneration Applications

To ensure a successful dental implant therapy, the presence of adequate vertical and horizontal alveolar bone is fundamental. However, an insufficient amount of alveolar ridge in both dimensions is often encountered in dental practice due to the consequences of oral diseases and tooth loss. Although postextraction socket preservation has been adopted to lessen the need for such invasive approaches, it utilizes bone grafting materials, which have limitations that could negatively affect the quality of bone formation. To overcome the drawbacks of routinely employed grafting materials, bone graft substitutes such as 3D scaffolds have been recently investigated in the dental field. In this review, we highlight different biomaterials suitable for 3D scaffold fabrication, with a focus on “3D-printed” ones as bone graft substitutes that might be convenient for various applications related to implant therapy. We also briefly discuss their possible adoption for periodontal regeneration.

A Clinical Evaluation of Biphasic Calcium Phosphate Alloplast with and without a Flowable Bioabsorbable Guided Tissue Regeneration Barrier in the Treatment of Mandibular Molar Class II Furcation Defects

BACKGROUND

Guided tissue regeneration (GTR) therapy has shown good results in the management of mandibular molar class II furcation defects. Advances in biomaterial sciences have developed alloplastic bone replacement graft materials and bioabsorbable GTR barrier membranes with good biologic response and handling properties. The aim of this study was to compare the attachment gain and the bone fill obtained with an alloplast [biphasic calcium phosphate (BCP) 60% hydroxyapatite (HA) and 40% beta tricalcium phosphate (b-TCP)] with and without a bioabsorbable GTR barrier [flowable poly (DL-lactide) (PLA) dissolved in N-methyl-2-pyrrolidone (NMP)] in the treatment of mandibular molar class II furcation defects.

MATERIALS AND METHODS

A total of 20 class II furcation defects were treated in 16 patients with chronic periodontitis in a comparative study. Ten defects were treated with Camceram(®) (BCP 60% HA and 40% - TCP) bone replacement graft material (group I) and 10 defects with a combination of Camceram® bone replacement graft material with Atrisorb® Freeflow™, bio-absorbable GTR barrier (flowable PLA dissolved in NMP) (group II). At baseline and at 6 months postsurgery, clinical parameters of vertical probing depth (PD) and horizontal probing depth (P-H), clinical attachment level (CAL), gingival recession (GR), and vertical depth of furcation defect (VDF) and horizontal depth of furcation defect (BP-H) were evaluated.

RESULTS

Statistical analysis was done with the Statistical Package for Social Sciences (SPSS) program. Intergroup comparisons made at 6 months postsurgery by unpaired Student's t-test showed mean reduction in PD in group I was 3.10 ± 0.73 mm and in group II was 3.20 ± 1.03 mm (p > 0.05). Mean reduction in P-H in group I was 1.60 ± 0.69 mm and in group II was 1.90 ± 0.73 mm (p > 0.05). Gain in CAL in group I was 2.80 ± 1.03 mm and in group II was 2.90 ± 0.94 mm (p > 0.05). Change in GR in group I was -0.30 ± 0.48 mm and in group II was -0.30 ± 0.48 (p > 0.05). Reduction in VDF in group I was 1.30 ± 0.67 mm and in group II was 1.80 ± 0.63 mm (p ≤ 0.01). Reduction in BP-H in group I was 1.30 ± 0.67 mm and in group II was 1.90 ± 0.73 mm (p ≤ 0.05).

CONCLUSION

It was concluded that the combination technique of BCP alloplast with a flowable bioabsorbable GTR barrier led to better results in regard to defect bone fill as compared with when the BCP alloplast alone was used.

Clinical evaluation of hydroxyapatite and β-tricalcium phosphate composite graft in the treatment of intrabony periodontal defect: A clinico-radiographic study

Background and Objective:

Hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) grafts have shown to be effective in promoting the clinical signs of periodontal regeneration in intrabony defects. The aim of our study was to clinically and radiographically evaluate the efficacy of HA and β-TCP composite bone graft material in the treatment of intrabony three-wall defect.

Materials and Methods:

Twenty patients participated in this study. Interproximal bony defects were surgically treated with a combination of HA–βTCP (biphasic calcium phosphate). Changes in clinical parameters such as gingival status, probing pocket depth, clinical attachment, and radiographic estimation of the amount of bone fill were evaluated after 6 months postoperatively.

Statistical Analysis Used:

Student's “t” test.

Results:

This treatment modality resulted in significant pocket depth reduction and clinical attachment gain which were observed to be 2.938 mm (47.04%) and 3.188 mm (29.09%), respectively. The defect fill as seen radiographically was 3.204 mm (63.195%). All the differences were highly significant and in favor of postoperative group.

Conclusion:

The results of this study suggest that HA–βTCP (biphasic calcium phosphate) provides an added regenerative effect in promoting the clinical resolution of intrabony three-wall defects in patients with periodontitis.

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.

Calcium orthophosphates in dentistry

Dental caries, also known as tooth decay or a cavity, remains a major public health problem in the most communities even though the prevalence of disease has decreased since the introduction of fluorides for dental care. Therefore, biomaterials to fill dental defects appear to be necessary to fulfill customers' needs regarding the properties and the processing of the products. Bioceramics and glass-ceramics are widely used for these purposes, as dental inlays, onlays, veneers, crowns or bridges. Calcium orthophosphates belong to bioceramics but they have some specific advantages over other types of bioceramics due to a chemical similarity to the inorganic part of both human and mammalian bones and teeth. Therefore, calcium orthophosphates (both alone and as components of various formulations) are used in dentistry as both dental fillers and implantable scaffolds. This review provides brief information on calcium orthophosphates and describes in details current state-of-the-art on their applications in dentistry and dentistry-related fields. Among the recognized dental specialties, calcium orthophosphates are most frequently used in periodontics; however, the majority of the publications on calcium orthophosphates in dentistry are devoted to unspecified "dental" fields.

Biphasic, triphasic and multiphasic calcium orthophosphates

Biphasic, triphasic and multiphasic (polyphasic) calcium orthophosphates have been sought as biomaterials for reconstruction of bone defects in maxillofacial, dental and orthopedic applications. In general, this concept is determined by advantageous balances of more stable (frequently hydroxyapatite) and more resorbable (typically tricalcium orthophosphates) phases of calcium orthophosphates, while the optimum ratios depend on the particular applications. Therefore, all currently known biphasic, triphasic and multiphasic formulations of calcium orthophosphate bioceramics are sparingly soluble in water and, thus, after being implanted they are gradually resorbed inside the body, releasing calcium and orthophosphate ions into the biological medium and, hence, seeding new bone formation. The available formulations have already demonstrated proven biocompatibility, osteoconductivity, safety and predictability in vitro, in vivo, as well as in clinical models. More recently, in vitro and in vivo studies have shown that some of them might possess osteoinductive properties. Hence, in the field of tissue engineering biphasic, triphasic and multiphasic calcium orthophosphates represent promising biomaterials to construct various scaffolds capable of carrying and/or modulating the behavior of cells. Furthermore, such scaffolds are also suitable for drug delivery applications. This review summarizes the available information on biphasic, triphasic and multiphasic calcium orthophosphates, including their biomedical applications. New formulations are also proposed.

Biograft-HT as a bone graft material in the treatment of periodontal vertical defects and its clinical and radiological evaluation: Clinical study

Aim:

To determine the efficacy of Biograft-HT^® as a bone graft material in the treatment of vertical defects in generalized chronic periodontitis patients and their clinical and radiological evaluation.

Patients and Methods:

Twenty patients diagnosed with generalized chronic periodontitis having two or more vertical defects were selected for this study. Clinical parameters like plaque index, gingival index, probing pocket depth and clinical attachment levels were recorded at different points of time over six months. Radiographic evaluation included the depth of the bone defect and the percentage of bone defect fill and was carried out for both the groups at baseline, three months and six months. After recording clinical parameters and administering phase-1 therapy, the sites were randomly treated either with Biograft- HT^® or open flap debridement only.

Results:

At the end of six months there was a significant reduction in the plaque and gingival scores in both test and control groups. There was 64% decrease in probing pocket depth for the test site as compared to 54.52% decrease seen for the control group. Similarly there was an 84.82% gain in clinical attachment level from the baseline to six months post operatively for the experimental group in comparison to 68.83% gain for the control group. Furthermore, 43.57% bone fill was observed for the experimental site whereas only 17.98% of bone fill was evident in the control site.

Conclusion:

Biograft –HT improves healing outcomes, leads to a reduction of probing depth, a resolution of osseous defects and a gain in clinical attachment, compared with open flap debridement by itself.

The use of Straumann Bone Ceramic in a maxillary sinus floor elevation procedure: a clinical, radiological, histological and histomorphometric evaluation with a 6-month healing period

OBJECTIVES

In this study, we evaluated the quality and quantity of bone formation in maxillary sinus floor elevation procedure using a new fully synthetic biphasic calcium phosphate (BCP) consisting of a mixture of 60% hydroxyapatite and 40% of beta-tricalcium phosphate (Straumann Bone Ceramic).

MATERIAL AND METHODS

A unilateral maxillary sinus floor elevation procedure was performed in six patients using 100% BCP. Biopsy retrieval for histological and histomorphometric analysis was carried out before implant placement after a 6-month healing period.

RESULTS

In this study, the maxillary sinus floor elevation procedure with the use of BCP showed uneventful healing. Radiological evaluation after 6 months showed maintenance of vertical height gained immediately after surgery. Primary stability was achieved with all Straumann SLA dental implants of 4.1 mm diameter and 10 or 12 mm length. The implants appeared to be osseointegrated well after a 3-month healing period. Histological investigation showed no signs of inflammation. Cranial from the native alveolar bone, newly formed mineralized tissue was observed. Also, osteoid islands as well as connective tissue were seen around the BCP particles, cranial from the front of newly formed mineralized tissue. Close bone-to-substitute contact was observed. Histomorphometric analysis showed an average bone volume/total volume (BV/TV) of 27.3% [standard deviation (SD) 4.9], bone surface/total volume (BS/TV) 4.5 mm(2)/mm(3) (SD 1.1), trabecula-thickness (TbTh) 132.1 mum (SD 38.4), osteoid-volume/bone volume (OV/BV) 7.5% (SD 4.3), osteoid surface/bone surface (OS/BS) 41.3% (SD 28.5), osteoid thickness (O.Th) 13.3 mum (SD 4.7) and number of osteoclasts/total area (N.Oc/Tar) 4.4 1/mm (SD 5.7).

CONCLUSIONS

Although a small number of patients were treated, this study provides radiological and histological evidence in humans confirming the suitability of this new BCP for vertical augmentation of the atrophied maxilla by means of a maxillary sinus floor elevation procedure allowing subsequent dental implant placement after a 6-month healing period. The newly formed bone had a trabecular structure and was in intimate contact with the substitute material, outlining the osteoconductive properties of the BCP material. Bone maturation was evident by the presence of lamellar bone.

Influence of calcium chloride and aprotinin in the in vivo biological performance of a composite combining biphasic calcium phosphate granules and fibrin sealant

Highly bioactive biomaterials have been developed to replace bone grafts in orthopedic revision and maxillofacial surgery for bone augmentation. A mouldable, self-hardening material can be obtained by combining TricOs Biphasic Calcium Phosphate Granules and Tissucol Fibrin Sealant. Two components, calcium chloride and antifibrinolytic agents (aprotinin), are essential for the stability of the fibrin clot. The ingrowth of cells in composites combining sealants without calcium chloride or with a low concentration of aprotinin was evaluated in vivo in an experiment on rabbits. Bone colonization was compared using TricOs alone or with the composite made from TricOs and the standard fibrin sealant. Without the addition of calcium chloride, the calcium ions released by the ceramic component interacted with the components of the sealant too late to stabilize the clot. With a low concentration of aprotinin, the degradation of the clot occurred more quickly, leading to the absence of a scaffold on which the bone cells could colonize the composite. Our results indicate that a stable fibrin scaffold is crucial for bone colonization. The low calcium chloride and low aprotinin groups have shown lower bone growth. Further studies will be necessary to determine the minimal amount of antifibrinolytic agent (aprotinin) necessary to allow the same level of osteogenic activity as the TricOs-fibrin glue composite.

Randomized clinical trials in implant therapy: relationships among methodological, statistical, clinical, paratextual features and number of citations

OBJECTIVES

The aim of the present study was to investigate the relationships among reported methodological, statistical, clinical and paratextual variables of randomized clinical trials (RCTs) in implant therapy, and their influence on subsequent research.

MATERIALS AND METHODS

The material consisted of the RCTs in implant therapy published through the end of the year 2000. Methodological, statistical, clinical and paratextual features of the articles were assessed and recorded. The perceived clinical relevance was subjectively evaluated by an experienced clinician on anonymous abstracts. The impact on research was measured by the number of citations found in the Science Citation Index. A new statistical technique (Structural learning of Bayesian Networks) was used to assess the relationships among the considered variables.

RESULTS

Descriptive statistics revealed that the reported methodology and statistics of RCTs in implant therapy were defective. Follow-up of the studies was generally short. The perceived clinical relevance appeared to be associated with the objectives of the studies and with the number of published images in the original articles. The impact on research was related to the nationality of the involved institutions and to the number of published images.

CONCLUSIONS

RCTs in implant therapy (until 2000) show important methodological and statistical flaws and may not be appropriate for guiding clinicians in their practice. The methodological and statistical quality of the studies did not appear to affect their impact on practice and research. Bayesian Networks suggest new and unexpected relationships among the methodological, statistical, clinical and paratextual features of RCTs.

Effects of Bioactive Glass on Bone Augmentation Within a Titanium Cap in Rabbit Parietal Bone

BACKGROUND

The condition of alveolar bone influences the success and subsequent esthetics of implant treatment. This study investigated the early effects of bioactive glass (BG) on bone augmentation within a hemispherical titanium cap in rabbit parietal bone.

METHODS

Twelve adult male Japanese white rabbits were used. One titanium cap (test site) was packed with BG in a collagen gel, and the other (control site) was packed with the collagen gel alone. After 1 and 3 months, animals were euthanized, and the experimental area was examined using fluorescence and light microscopy.

RESULTS

Newly generated bone was observed at 1 and 3 months of healing. Although bone was also generated without BG, newly mineralized bone was generated sooner with BG present for guided bone augmentation than without BG. At 1 and 3 months, the BG was not bioabsorbed completely, and some particles remained.

CONCLUSION

New bone is generated at an early stage of bone formation using BG for bone augmentation.

Cage containing a biphasic calcium phosphate ceramic (Triosite) for the treatment of cervical spondylosis

BACKGROUND

We evaluated the fusion efficacy and clinical outcomes of a cage containing a biphasic calcium phosphate ceramic (Triosite) in treating cervical spondylosis.

METHODS

We randomly divided 100 patients with cervical spondylosis undergoing anterior discectomy with interbody polyetheretherketone (PEEK) fusion into 2 groups in the past 2 years: group A (n = 50), PEEK cage containing a biphasic calcium phosphate ceramic (Triosite), and group B (n = 50), PEEK cage containing an autogenous iliac bone graft. We compared the fusion rate, fusion time, spinal curvature, and neuroforamen size between the 2 groups. We also compared excess operation time, excess blood loss, hospital stay, complications, and neurological recovery status between the groups.

RESULTS

The fusion rates were 57%, 67%, 77%, 82%, 92%, and 100% in group A and 81%, 86%, 95%, 95% 100%, and 100% in group B in the first 6 postoperative months. The fusion rate in group A was significantly lower than that in group B in the first 5 months after the procedure (P < .05 and P < .01, respectively), but the fusion rate reached 100% in both groups by the sixth month. Within the first 6 months, as the fusion level increased, the fusion rates reduced and time to fusion was delayed in both groups. There were no donor site complications in group A. However, 3 patients (6%) from group B experienced complications (1, wound infection; 1, numbness of thigh; and 1, subcutaneous hematoma) (P < .001). The hospital stay was shorter in group A (4.43 +/- 2.36 days) than in group B (7.00 +/- 3.77 days) (P = .001). The mean excessive blood loss and excessive operative time for an iliac bone graft in group B were 15 +/- 5 mL and 10 +/- 6 minutes. There was no statistical significance in spinal curve correction, neuroforamen enlargement, and neurological recovery.

CONCLUSIONS

A cage containing a biphasic calcium phosphate ceramic resulted in complete fusion by the sixth postoperative month, although the fusion rate was lower than that in a cage containing an autograft during the first 5 months after the operation and the time to fusion was delayed. Using a cage containing a biphasic calcium phosphate ceramic leads to a shorter hospital stay, less blood loss, shorter operative time, and no donor site complications. It seemed to be a good substitute for cervical spondylotic fusion.

Alveolar bone regeneration for immediate implant placement using an injectable bone substitute: an experimental study in dogs

BACKGROUND

The aim of the present study was to assess the efficacy of a ready-to-use injectable bone substitute for bone regeneration around dental implants placed into fresh extraction sockets.

METHODS

Third and fourth mandibular premolars were extracted from three beagle dogs and the interradicular septa were surgically reduced to induce a mesial bone defect. Thereafter, titanium implants were immediately placed. On the left side of the jaw, mesial bone defects were filled with an injectable bone substitute (IBS), obtained by combining a polymer and biphasic calcium phosphate ceramic granules. The right defects were left unfilled as controls. After 3 months of healing, specimens were prepared for histological and histomorphometric evaluations.

RESULTS

No post-surgical complications were observed during the healing period. In all experimental conditions, histological observations revealed a lamellar bone formation in contact with the implant. Histomorphometric analysis showed that IBS triggers a significant (P<0.05) increase in terms of the number of threads in contact with bone, bone-to-implant contact, and peri-implant bone density of approximately 8.6%, 11.0%, and 14.7%, respectively. In addition, no significant difference was observed when number of threads, bone-to-implant contact, and bone density in the filled defects were compared to the no-defect sites.

CONCLUSION

It is concluded that an injectable bone substitute composed of a polymeric carrier and calcium phosphate significantly increases bone regeneration around immediately placed implants.

The efficacy of bone replacement grafts in the treatment of periodontal osseous defects. A systematic review

BACKGROUND

Bone replacement grafts (BRG) are widely used in the treatment of periodontal osseous defects; however, the clinical benefits of this therapeutic practice require further clarification through a systematic review of randomized controlled studies.

RATIONALE

The purpose of this systematic review is to access the efficacy of bone replacement grafts in proving demonstrable clinical improvements in periodontal osseous defects compared to surgical debridement alone.

FOCUSED QUESTION

What is the effect of bone replacement grafts compared to other interventions on clinical, radiographic, adverse, and patient-centered outcomes in patients with periodontal osseous defects?

SEARCH PROTOCOL

The computerized bibliographical databases MEDLINE and EMBASE were searched from 1966 and 1974, respectively, to October 2002 for randomized controlled studies in which bone replacement grafts were compared to other surgical interventions in the treatment of periodontal osseous defects. The search strategy included screening of review articles and reference lists of retrieved articles as well as hand searches of selected journals.

INCLUSION CRITERIA

All searches were limited to human studies in English language publications.

EXCLUSION CRITERIA

Non-randomized observational studies (e.g., case reports, case series), publications providing summary statistics without variance estimates or data to permit computation, and studies without BRG intervention alone were excluded.

DATA COLLECTION AND ANALYSIS

The therapeutic endpoints examined included changes in bone level, clinical attachment level, probing depth, gingival recession, and crestal resorption. For purposes of meta-analysis, change in bone level (bone fill) was used as the primary outcome measure, measured upon surgical re-entry or transgingival probing (sounding).

MAIN RESULTS

1. Forty-nine controlled studies met eligibility criteria and provided clinical outcome data on intrabony defects following grafting procedures. 2. Seventeen studies provided clinical outcome data on BRG materials for the treatment of furcation defects.

REVIEWERS' CONCLUSIONS

1. With respect to the treatment of intrabony defects, the results of meta-analysis supported the following conclusions: 1) bone grafts increase bone level, reduce crestal bone loss, increase clinical attachment level, and reduce probing depth compared to open flap debridement (OFD) procedures; 2) No differences in clinical outcome measures emerge between particulate bone allograft and calcium phosphate (hydroxyapatite) ceramic grafts; and 3) bone grafts in combination with barrier membranes increase clinical attachment level and reduce probing depth compared to graft alone. 2. With respect to the treatment of furcation defects, 15 controlled studies provided data on clinical outcomes. Insufficient studies of comparable design were available to submit data to meta-analysis. Nonetheless, outcome data from these studies generally indicated positive clinical benefits with the use of grafts in the treatment of Class II furcations. 3. With respect to histological outcome parameters, 2 randomized controlled studies provide evidence that demineralized freeze-dried bone allograft (DFDBA) supports the formation of a new attachment apparatus in intrabony defects, whereas OFD results in periodontal repair characterized primarily by the formation of a long junctional epithelial attachment. Multiple observational studies provide consistent histological evidence that autogenous and demineralized allogeneic bone grafts support the formation of new attachment. Limited data also suggest that xenogenic bone grafts can support the formation of a new attachment apparatus. In contrast, essentially all available data indicate that alloplastic grafts support periodontal repair rather than regeneration. 4. The results of this systematic review indicate that bone replacement grafts provide demonstrable clinical improvements in periodontal osseous defects compared to surgical debridement alone.

A systematic review of graft materials and biological agents for periodontal intraosseous defects

OBJECTIVES

To determine the adjunctive effect of grafting biomaterials/biological agents with open flap debridement (OFD) in the treatment of deep intraosseous defects.

BACKGROUND

No systematic review of treatment outcomes in patients who received graft biomaterials or biological agents have been published.

METHODS

A rigorous systematic review of randomized controlled trials of at least 6-month duration was conducted comparing grafting biomaterials/biological agents (alone or in combination) + OFD (test group) to OFD alone or in combination with a placebo (control group).

RESULTS

The difference in CAL change between test and control groups varied from -1.45 mm to 1.40 mm with respect to different biomaterials/biological agents. Meta-analysis showed that CAL change significantly improved after treatment for coralline calcium carbonate (weighted mean difference 0.90 mm; 95% CI: 0.53-1.27), bioactive glass (weighted mean difference 1.04 mm; 95% CI: 0.31-1.76), hydroxyapatite (weighted mean difference 1.40 mm, 95% CI 0.64-2.16), and enamel matrix proteins (weighted mean difference 1.33 mm, 95% CI 0.78-1.88). However, heterogeneity in results between studies was highly statistically significant for most of biomaterials/biologicals and could not be fully explained.

CONCLUSIONS

Overall, the use of specific biomaterials/biologicals was more effective than OFD in improving attachment levels in intraosseous defects. Difference in CAL gain varied greatly with respect to different biomaterial/biological agent. Due to a significant heterogeneity in results between studies in most treatment groups, general conclusions about the expected clinical benefit of graft biomaterials/biologicals need to be interpreted with caution. Further research should focus on understanding this variability.

A synthetic porous ceramic as a bone graft substitute in the surgical management of scoliosis: a prospective, randomized study

STUDY DESIGN

A prospective randomized study.

OBJECTIVES

To assess the clinical and radiologic performances of a synthetic ceramic as a bone graft substitute in scoliosis surgery.

SUMMARY OF BACKGROUND DATA

Surgery on the skeleton frequently requires harvesting of autogenous bone grafts from the pelvis, but this procedure often is complicated by problems.

METHODS

Fifty-eight patients with idiopathic scoliosis, ages 13 to 25 years, were treated by posterior correction and arthrodesis using Cotrel-Dubousset instrumentation. Posterior spinal fusion was performed using local bone grafts combined with autogenous iliac bone grafts in 30 patients, and combined with porous biphasic calcium phosphate ceramic blocks comprising hydroxyapatite and tricalcium phosphate in another 28 patients. The patients were observed for a minimum of 24 months after surgery, with a mean postoperative observation time of 48 months. The results were assessed clinically and radiographically.

RESULTS

Patients in the ceramic group had a lower average blood loss than those in the iliac graft group. They also were free from postoperative local complications in the iliac region, which were experienced by a significantly high proportion of patients belonging to the iliac graft group. Radiography demonstrated successful incorporation of the ceramic blocks within 12 months. The correction of the deformity was maintained similarly and satisfactorily in both groups.

CONCLUSIONS

These results justify and favor the use of calcium phosphate ceramics as bone graft substitutes for instrumented posterior spinal fusion in teenagers and young adults. Potentially hazardous harvesting of pelvic bone is no longer necessary for such operations.

Equivalence and superiority testing in regeneration clinical trials

The purpose of this report is to investigate sample size requirements for both equivalence and superiority studies investigating products used in regeneration. The goal of a superiority clinical trial is to determine if a new therapy is superior to an established therapy or placebo. In contrast to superiority trials, equivalence trials are used to determine if a new product has similar therapeutic properties to an established product. The sample sizes for the two different types of clinical trials were based on the following assumptions: an alpha of 0.05, a power of 0.80, a 2 group parallel arm study, and equal variances and sample sizes for both groups. Separate sample size calculations were done for both intrabony defects and Class II furcation defects. Sample sizes for the equivalence and superiority trials using the same criteria were the same. However, criteria for estimating sample sizes for equivalence clinical trials require much smaller differences between groups, resulting in much larger sample sizes. A criterion of a 20% difference between groups of the total therapeutic effect resulted in sample sizes which ranged from 64 to 127 in equivalence clinical trials. These samples sizes are much larger than have been generally used in clinical trials investigating periodontal regeneration.

Periodontal regeneration around natural teeth

1. Evidence is conclusive (Table 2) that periodontal regeneration in humans is possible following the use of bone grafts, guided tissue regeneration procedures, both without and in combination with bone grafts, and root demineralization procedures. 2. Clinically guided tissue regeneration procedures have demonstrated significant positive clinical change beyond that achieved with debridement alone in treating mandibular and maxillary (buccal only) Class II furcations. Similar data exist for intraosseous defects. Evidence suggests that the use of bone grafts or GTR procedures produce equal clinical benefit in treating intraosseous defects. Further research is necessary to evaluate GTR procedures compared to, or combined with, bone grafts in treating intraosseous defects. 3. Although there are some data suggesting hopeful results in Class II furcations, the clinical advantage of procedures combining present regenerative techniques remains to be demonstrated. Additional randomized controlled trials with sufficient power are needed to demonstrate the potential usefulness of these techniques. 4. Outcomes following regenerative attempts remain somewhat variable with differences in results between studies and individual subjects. Some of this variability is likely patient related in terms of compliance with plaque control and maintenance procedures, as well as personal habits; e.g., smoking. Variations in the defects selected for study may also affect predictability of outcomes along with other factors. 5. There is evidence to suggest that present regenerative techniques lead to significant amounts of regeneration at localized sites on specific teeth. However, if complete regeneration is to become a reality, additional stimuli to enhance the regenerative process are likely needed. Perhaps this will be accomplished in the future, with combined procedures that include appropriate polypeptide growth factors or tissue factors to provide additional stimulus.

Recent advances in periodontal diagnosis and treatment: exploring new treatment alternatives

A better understanding of the etiology and pathogenesis of periodontal diseases provides clinicians and researchers with a number of new diagnostic techniques and treatment alternatives. These new developments may also offer the clinician additional information for treatment planning.