Clinical and Histologic Evaluation of Granular Beta-Tricalcium Phosphate for the Treatment of Human Intrabony Periodontal Defects: A Report on Five Cases

Optimizing esthetic zone periodontal regeneration in a 1-2-wall infrabony defect using recombinant human platelet-derived growth factor BB and β-tricalcium phosphate: A case report

OBJECTIVE

Periodontitis is an inflammatory condition induced by subgingival bacterial dysbiosis, resulting in inflammatory-mediated destruction of tooth-supporting structures, potentially leading to the formation of infrabony defects. This case report describes the treatment of a patient who presented with a combination 1-2-wall defect on tooth 21. To maintain the residual periodontal attachment and minimize esthetic consequences, a regenerative approach was performed using recombinant human platelet-derived growth factor-BB (rh-PDGF-BB) and β-tricalcium phosphate (β-TCP).

MATERIALS AND METHODS

At the time of postscaling/root planing reevaluation, a 34-year-old Asian male initially diagnosed with molar/incisor pattern stage III grade C periodontitis exhibited a 6-mm residual probing depth on the mesiopalatal aspect of tooth 21. Periodontal regenerative surgery was performed using rh-PDGF-BB with β-TCP, without the use of a membrane.

RESULTS

At the 1-year follow-up, a significant reduction in probing depth and radiographic evidence of bone fill were observed. Additionally, re-entry surgery for implant placement at site tooth 23 confirmed bone fill in the defect on tooth 21.

CONCLUSION

These results demonstrate the efficacy of rh-PDGF-BB with β-TCP in enhancing periodontal regeneration and support its use as a treatment option when treating poorly contained infrabony defects in the esthetic zone.

Immuno-histologic and histomorphometric evaluation of Angelica sinensis adjunctive to ß-tricalcium phosphate in critical-sized class II furcation defects in dogs

OBJECTIVE

The study evaluates the effectiveness of Angelica sinensis (As) adjunctive to Beta-tricalcium phosphate (β-TCP) bone graft in the management of induced critical sized class II furcation defects in dogs.

MATERIAL AND METHOD

A randomized study design was conducted on the third and fourth premolars of six dogs. A total of twenty-four defects were surgically created. After reflecting a mucoperiosteal flap, twelve defects were filled with As granules mixed with β-TCP (Experimental group) while the other twelve defects were filled with β-TCP only (Control group) and both were covered by collagen membrane. At the fourth and eighth weeks, jaw segments were dissected and processed for immune-histological examination and histomorphometry analysis.

RESULTS

At four and eight weeks after treatment, experimental group showed a statistically significant increase in the height of newly formed interradicular bone (p = 0.001 and p = 0.0001 respectively), its surface area (p = 0.002 and p = 0.02 respectively), and the thickness of its trabeculae (p = 0.0001 and p = 0.001 respectively), when compared to control group. Moreover. alkaline phosphatase immunoreaction showed higher intensity in the osteoblast cells of experimental group compared to control group.

CONCLUSION

As enhances periodontal regeneration and bone-formation when used in the management of furcation defects.

Histologic and histomorphometric evaluation of Aloe vera adjunctive to β-tricalcium phosphate in class II furcation defects in dogs

Aloe vera has antimicrobial activity and enhances the osseointegration process, thus it may have the potential in treating periodontal defects. This study aimed to evaluate the effect of Aloe vera as an adjunction to Beta-tricalcium phosphate (β-TCP) bone graft in Grade II furcation defects. A randomized study was conducted on six healthy mongrel dogs' premolars. A total of twenty-four Grade II furcation critical-sized defects were surgically created after reflecting a full-thickness flap, twelve defects were filled with β-TCP while the other twelve defects were filled with Aloe vera mixed with β-TCP and both covered by collagen membrane. Animals were euthanized at the end of the fourth and eighth week and defects were analyzed histologically and histomorphometrically. Histologically, Aloe vera mixed with β-TCP resulted in more bone formation and new PDL fibers compared to β-TCP alone. After 2 and 4 weeks, the experimental group had significantly higher newly formed interradicular bone height (p < 0.0001, and p < 0.0001, respectively), bone thickness (p < 0.0001, and p < 0.0001, respectively), and percentage of the surface area (p = 0.009, and p = 0.023, respectively). Aloe vera gel adjunctive to β-TCP is an effective bioactive agent that enhances periodontal tissue regeneration and bone formation in critically sized defects.

Periodontal Therapy Using Bioactive Glasses: A Review

This paper reviews the use of bioactive glasses as materials for periodontal repair. Periodontal disease causes bone loss, resulting in tooth loosening and eventual tooth loss. However, it can be reversed using bioactive glass, typically the original 45S5 formulation (Bioglass®) at the defect site. This is done either by plcing bioactive glass granules or a bioactive glass putty at the defect. This stimulates bone repair and causes the defect to disappear. Another use of bioactive glass in periodontics is to repair so-called furcation defects, i.e., bone loss due to infection at the intersection of the roots in multi-rooted teeth. This treatment also gives good clinical outcomes. Finally, bioactive glass has been used to improve outcomes with metallic implants. This involves either placing bioactive glass granules into the defect prior to inserting the metal implant, or coating the implant with bioactive glass to improve the likelihood of osseointegration. This needs the glass to be formulated so that it does not crack or debond from the metal. This approach has been very successful, and bioactive glass coatings perform better than those made from hydroxyapatite.

Regenerative potential of biphasic calcium phosphate and enamel matrix derivatives in the treatment of isolated interproximal intrabony defects: a randomized controlled trial

Background

The combined use of biomaterials for regeneration may have great biological relevance. This study aimed to compare the regenerative potential of biphasic calcium phosphate (BCP) alone and with growth factor enamel matrix derivatives (EMDs) for the regeneration of intrabony defects at 1 year.

Methods

This randomized controlled trial included 40 sites in 29 patients with stage II/III periodontitis and 2/3 wall intrabony defects that were treated with BCP alone (control group) or a combination of BCP and EMD (test group). BCP alloplastic bone grafts provide better bio-absorbability and accelerate bone formation. EMDs are commercially available amelogenins. Mean values and standard deviations were calculated for the following parameters: plaque index (PI), papillary bleeding index (PBI), vertical probing pocket depth (V-PPD), vertical clinical attachment level (V-CAL), and radiographic defect depth (RDD). Student paired and unpaired t-tests were used to compare the data from baseline to 12 months for each group and between the groups, respectively. The results were considered statistically significant at p<0.05.

Results

At 12 months, the PI and PBI scores of the control and test groups were not significantly different (p>0.05). The mean V-PPD difference, V-CAL gain, and RDD difference were statistically significant in both groups at 12 months (p<0.001 for all parameters). Intergroup comparisons showed that the mean V-PPD reduction (2.13±1.35 mm), V-CAL gain (2.53±1.2 mm), and RDD fill (1.33±1.0 mm) were statistically significant between the groups at 12 months (p<0.001 for all parameters).

Conclusion

BCP and EMDs combination is a promising modality for the regeneration of intrabony defects.

Bone Regeneration Using Autologous Adipose-Derived Stem Cell Spheroid Complex

Bone defects require reconstruction using various biomaterials or non-biological materials. Stem cell spheroids can be used for scaffold-free approaches for osteogenesis. We set up a culture method for creating an optimal osteogenic adipose-derived stem cell (ADSC) spheroid complex by measuring the expression of protein in a sequential series of culture media. After culturing ADSC spheroids for 24 hours in DMEM, the spheroids were cultured in ascorbic acid-containing medium for five days followed by osteoblast differentiation medium. One day after exchanging to osteoblast differentiation medium, spheroids were collected and cultured for four days to obtain a spheroid complex. Each culture period was determined by analyzing the expression of collagen type I, alkaline phosphatase and integrin α5 to maximize the activity of ADSC spheroids. The expression of collagen type I increased significantly in ascorbic acid-containing medium (p < 0.05) compared with control medium on day five, suggesting that culturing spheroids in ascorbic acid increases collagen synthesis. RNA was extracted from ADSC spheroids after 1, 3, 5, and 7 days in each medium and RT-PCR was performed to measure integrin α5 expression. The expression was transiently high on the first day of osteoblast differentiation culture and then gradually decreased. Osteoblast differentiation medium enhanced cell adhesion in spheroids. An in vivo study confirmed the osteogenic potential of the ADSC spheroid complex created by the established protocol. The ADSC spheroid complex stimulated bone regeneration and will be applied to the treatment of large bone defects.

Comparison of periodontal wound healing/regeneration by recombinant human fibroblast growth factor-2 combined with β-tricalcium phosphate, carbonate apatite, or deproteinized bovine bone mineral in a canine one-wall intra-bony defect model

AIM

To evaluate periodontal wound healing/regeneration of one-wall intra-bony defects treated with recombinant human fibroblast growth factor-2 (rhFGF-2) and beta-tricalcium phosphate (β-TCP), carbonate apatite (CO₃ Ap), or deproteinized bovine bone mineral (DBBM) in dogs.

MATERIALS AND METHODS

The stability of rhFGF-2 adsorbed onto the bone substitutes was evaluated by Enzyme-Linked Immunosorbent Assay (ELISA). One-wall intra-bony defects (5 × 5 × 5 mm) created in five adult male beagle dogs were treated with rhFGF-2 alone (rhFGF-2), rhFGF-2 with β-TCP (rhFGF-2/β-TCP), rhFGF-2 with CO₃ Ap (rhFGF-2/CO₃ Ap), or rhFGF-2 with DBBM (rhFGF-2/DBBM). Histological outcomes (e.g., linear length of new cementum adjacent to the newly formed bone with inserting collagen fibres [NA] as the primary outcome) were evaluated at 10 weeks post surgery.

RESULTS

Significantly higher amount of rhFGF-2 was adsorbed onto CO₃ Ap compared with β-TCP. Among the treatment groups, the rhFGF-2/DBBM group showed the highest amount of periodontal tissue regeneration. The rhFGF-2/DBBM group showed significantly greater formation of NA (3.22 ± 0.40 mm) compared with rhFGF-2 (1.17 ± 1.00 mm, p < .01) group. Additionally, new bone area in the rhFGF-2/DBBM group (9.78 ± 2.30 mm² ) was significantly higher than that in the rhFGF-2 (5.08 ± 1.26 mm² , p < .01), rhFGF-2/β-TCP (5.91 ± 1.27 mm² , p < .05), and rhFGF-2/CO₃ Ap (6.51 ± 1.49 mm² , p < .05) groups. Slight ankylosis was found in the rhFGF-2/β-TCP (1/9 sites), rhFGF-2/CO₃ Ap (3/10 sites), and rhFGF-2/DBBM (1/9 sites) groups.

CONCLUSIONS

Within their limitations, the present data indicate that DBBM seems to be a suitable carrier for rhFGF-2 and that rhFGF-2/DBBM treatment promotes favourable periodontal regeneration compared with rhFGF-2, rhFGF-2/β-TCP, and rhFGF-2/CO₃ Ap treatments in one-wall intra-bony defects.

Apical approach in periodontal reconstructive surgery with enamel matrix derivate and enamel matrix derivate plus bone substitutes: a randomized, controlled clinical trial

Objectives

This parallel, randomized controlled clinical trial evaluated the influence of bone substitutes (BS) on the efficacy of the non-incised papillae surgical approach (NIPSA) with enamel matrix derivate (EMD) in resolving deep, isolated, combined non-contained intrabony and supra-alveolar periodontal defects, preserving the soft tissue.

Material and methods

Twenty-four patients were randomized to treatment with NIPSA and EMD or NIPSA plus EMD and BS. Bleeding on probing (BoP), interproximal clinical attachment level (CAL), interproximal probing depth (PD), recession (REC), location of the tip of the papilla (TP), and width of the keratinized tissue (KT) were evaluated before surgery and at 1 year post-surgery (primary outcomes). Wound closure was assessed at 1 week post‐surgery, and supra‐alveolar attachment gain (SUPRA-AG) was recorded at 1 year post‐surgery.

Results

At 1 week, 87.5% of cases registered complete wound closure and there were no cases of necrosis, without differences between groups (p > .05). At 1 year, all cases showed negative BoP. A significant PD reduction (NIPSA + EMD 8.25 ± 2.70 mm vs. NIPSA + EMD + BS 6.83 ± 0.81 mm) and CAL gain (NIPSA + EMD 8.33 ± 2.74 mm vs. NIPSA + EMD + BS 7.08 ± 2.68 mm) were observed (p < .001) in both groups, without significant between-group differences (p > .05). The residual PD was < 5 mm in all defects (NIPSA + EMD 2.50 ± 0.67 mm vs. NIPSA + EMD + BS 2.67 ± 0.78 mm). Soft tissues were preserved without significant between-group differences (REC: NIPSA + EMD 0.25 ± 0.45 mm vs. NIPSA + EMD + BS 0.17 ± 0.58 mm, p > .05; KT: 0.00 ± 0.43 mm vs. 0.08 ± 0.67 mm, p > .05). There were improvements in the papilla in both groups (TP: NIPSA + EMD 0.33 ± 0.49 mm vs. NIPSA + EMD + BS 0.45 ± 0.52 mm, p > .05), which was only significant in the NIPSA EMD + BS group (0.45 ± 0.52 mm; p < .05). In both groups, CAL gain was recorded in the supra-alveolar component, showing full resolution of the intrabony component of the defect in all cases (SUPRA-AG: NIPSA + EMD 1.83 ± 1.11 mm vs. NIPSA + EMD + BS 2.00 ± 1.76 mm, p > .05).

Conclusions

NIPSA and EMD with or without BS seem to be a valid surgical approach in the treatment of isolated, deep non-contained periodontal defects. In our study, both treatments resulted in significant PD reduction and CAL gain, that extended in the supra-alveolar component, without differences with the use of BS. Both treatments resulted in soft tissue preservation. However, the addition of BS may improve interdental papillary tissue.

Clinical relevance

NIPSA, with or without bone substitutes, resulted in significant periodontal improvement, with soft tissue preservation in isolated, deep non-contained periodontal defects. The application of bone substitutes may provide interproximal soft tissue gain.

Clinical trial registration

Clinicaltrials.gov: NCT04712630.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00784-021-04256-1.

Activation of NLRP3 Inflammasome Complexes by Beta-Tricalcium Phosphate Particles and Stimulation of Immune Cell Migration in vivo

Beta-tricalcium phosphate (β-TCP) serves as a bone substitute in clinical practice because it is resorbable, biocompatible, osteointegrative, and osteoconductive. Particles of β-TCP are also inflammatory mediators although the mechanism of this function has not been fully elucidated. Regardless, the ability of β-TCP to stimulate the immune system might be useful for immunomodulation. The present study aimed to determine the effects of β-TCP particles on NLR family pyrin domain containing 3 (NLRP3) inflammasome complexes. We found that β-TCP activates NLRP3 inflammasomes, and increases interleukin (IL)-1β production in primary cultured mouse dendritic cells (DCs) and macrophages, and human THP-1 cells in caspase-1 dependent manner. In THP-1 cells, β-TCP increased also IL-18 production, and NLRP3 inflammasome activation by β-TCP depended on phagocytosis, potassium efflux, and reactive oxygen species (ROS) generation. We also investigated the effects of β-TCP in wild-type and NLRP3-deficient mice in vivo. Immune cell migration around subcutaneously injected β-TCP particles was reduced in NLRP3-deficient mice. These findings suggest that the effects of β-TCP particles in vivo are at least partly mediated by NLRP3 inflammasome complexes.

Bone Grafts and Substitutes in Dentistry: A Review of Current Trends and Developments

After tooth loss, bone resorption is irreversible, leaving the area without adequate bone volume for successful implant treatment. Bone grafting is the only solution to reverse dental bone loss and is a well-accepted procedure required in one in every four dental implants. Research and development in materials, design and fabrication technologies have expanded over the years to achieve successful and long-lasting dental implants for tooth substitution. This review will critically present the various dental bone graft and substitute materials that have been used to achieve a successful dental implant. The article also reviews the properties of dental bone grafts and various dental bone substitutes that have been studied or are currently available commercially. The various classifications of bone grafts and substitutes, including natural and synthetic materials, are critically presented, and available commercial products in each category are discussed. Different bone substitute materials, including metals, ceramics, polymers, or their combinations, and their chemical, physical, and biocompatibility properties are explored. Limitations of the available materials are presented, and areas which require further research and development are highlighted. Tissue engineering hybrid constructions with enhanced bone regeneration ability, such as cell-based or growth factor-based bone substitutes, are discussed as an emerging area of development.

Medium- and long-term clinical benefits of periodontal regenerative/reconstructive procedures in intrabony defects: Systematic review and network meta-analysis of randomized controlled clinical studies

BACKGROUND

Systematic reviews have established the short-term improvements of periodontal regenerative/reconstructive procedures compared to conventional surgical treatment in intrabony defects. However, a hierarchy of periodontal regenerative/reconstructive procedures regarding the medium- to long-term results of treatment does not exist.

AIM

To systematically assess the literature to answer the focused question "In periodontitis patients with intrabony defects, what are the medium- and long-term benefits of periodontal regenerative/reconstructive procedures compared with open flap debridement (OFD), in terms of clinical and/or radiographic outcome parameters and tooth retention?".

MATERIAL & METHODS

Randomized controlled clinical trials (RCTs), reporting on clinical and/or radiographic outcome parameters of periodontal regenerative/reconstructive procedures ≥3 years post-operatively, were systematically assessed. Clinical [residual probing pocket depth (PD) and clinical attachment level (CAL) gain, tooth loss] and radiographic [residual defect depth (RDD), bone gain (RBL)] outcome parameters were assessed. Descriptive statistics were calculated, and Bayesian random-effects network meta-analyses (NMA) were performed where possible.

RESULTS

Thirty RCTs, presenting data 3 to 20 years after treatment with grafting, GTR, EMD, as monotherapies, combinations thereof, and/or adjunctive use of blood-derived growth factor constructs or with OFD only, were included. NMA based on 21 RCTs showed that OFD was clearly the least efficacious treatment; regenerative/reconstructive treatments resulted in significantly shallower residual PD in 4 out 8 comparisons [range of mean differences (MD): -2.37 to -0.60 mm] and larger CAL gain in 6 out 8 comparisons (range of MD: 1.26 to 2.66 mm), and combination approaches appeared as the most efficacious. Tooth loss after regenerative/reconstructive treatment was less frequent (0.4%) compared to OFD (2.8%), but the evidence was sparse. There were only sparse radiographic data not allowing any relevant comparisons.

CONCLUSION

Periodontal regenerative/reconstructive therapy in intrabony defects results, in general, in shallower residual PD and larger CAL gain compared with OFD, translating in high rates of tooth survival, on a medium (3-5 years) to long-term basis (5-20 years). Combination approaches appear, in general, more efficacious compared to monotherapy in terms of shallower residual PD and larger CAL gain. A clear hierarchy could, however, not be established due to limited evidence.

Biomaterials preparation by electrospinning of gelatin and sodium hyaluronate/gelatin nanofibers with non-toxic solvents

Gelatin (Ge) based fibers have been produced by electrospinning with a non-toxic solvent for preparing membranes usable in maxillofacial surgery. Ge and Ge/sodium hyaluronate (SH) nanofibers were successfully electrospun to produce membranes whose thickness was around 150 to 200μm. The mean fiber diameter reached a maximum of 660nm for Ge fibers and 210nm for Ge/SH fibers. The presence of Ge and SH was confirmed in the membranes by Raman spectroscopy. Ge membranes had low mechanical properties and only small samples of 0.5cm in size could be retrieved from the collector as larger sample tended to tear and break. Ge/SH membranes could be retrieved from the collector slightly easily. Membranes could be handled carefully but in vivo implantation could not be planned due to poor mechanical resistance. Crosslinking by glutaraldehyde vapors reduced the mean porosity of Ge membranes; it totally prevents membranes to be retrieved from the collector. Beta tricalcium phosphate (β-TCP) particles were added with Ge during electrospinning to increase osseointegration of the membranes and promote bone formation. β-TCP particles formed agglomerates outside the fibers, and we could not obtain β-TCP particles inside the Ge fibers due to their low diameter. In general, electrospun membranes lacked reproducibility. Despite the great interest of Ge-based membranes and Ge/β-TCP membranes, the low mechanical properties of the fibers, the lack of reproducibility and the difficulty to retrieve the membranes from the collector did not allow our biomaterials to be implanted or to be envisaged for industrial production.

Fabrication of calcium phosphate 3D scaffolds for bone repair using magnetic levitational assembly

The calcium phosphate particles can be used as building blocks for fabrication of 3D scaffolds intended for bone tissue engineering. This work presents for the first time a rapid creation of 3D scaffolds using magnetic levitation of calcium phosphate particles. Namely, tricalcium phosphate particles of equal size and certain porosity are used, which undergo the process of recrystallization after magnetic levitational assembly of the scaffold to ensure stitching of the scaffold. Label-free levitational assembly is achieved by using a custom-designed magnetic system in the presence of gadolinium salts, which allows the levitation of calcium phosphate particles. Chemical transformation of tricalcium- to octacalcium phosphate under the condition of magnetic levitation in non-homogeneous magnetic field is also demonstrated. This approach allows obtaining rapidly the octacalcium phosphate phase in the final 3D product, which is biocompatible.

Evaluation of the relative efficacy of autologous platelet-rich fibrin membrane in combination with β-tricalcium phosphate (Septodont- resorbable tissue replacement)™ alloplast versus β-TCP alloplast alone in the treatment of grade II furcation defects

Introduction:

Platelet-rich fibrin (PRF) is considered as the second-generation platelet concentrate, contains combined properties of fibrin, platelets, leukocytes, growth factors, and cytokines that make it as healing biomaterial with incredible potential for hard tissue and soft tissue regeneration. The present study was aimed to evaluate the effectiveness of PRF with β-tricalcium phosphate (β-TCP) graft (R. T. R) and compare it with β-TCP allograft alone in the treatment of mandibular Grade II furcation defects.

Material and Methods:

A total of 20 mandibular Grade II furcation defects sites were assigned in the study and treated with either β-TCP alone (Group I) or β-TCP with PRF membrane (Group II). The clinical parameters analyzed were probing pocket depth (PPD), clinical attachment level (CAL), gingival recession (GR), horizontal defect depth (HDD), and vertical defect depth (VDD), recorded baseline and at 6 months reentry.

Results:

At 6 months, both groups showed statistically significant results for all parameters from their baseline value, although intergroup changes were statistically insignificant. In Group I, gain in CAL was 2.80 ± 1.40 and in Group II it was 3.00 ± 1.44. Bone fill in Group I was VDD (3.50 ± 2.12) and HDD (3.70 ± 0.67), whereas Group II showed VDD (3.70 ± 1.57) and HDD (4.0 ± 0.88), respectively. PPD reduction was higher in Group I (3.50 ± 2.27) than Group II (2.80 ± 1.93). At reentry GR was established, Group I showed higher GR (0.70 ± 0.67) and Group II (0.40 ± 0.52).

Conclusions:

Significant improvement was found in both groups, but the combination of PRF with β-TCP allograft led to more favorable improvement in the management of Grade II furcation defect except PPD.

Immunohistopathologic evaluation of Drynaria fortunei rhizome extract in the management of Class II furcation defects in a canine model

BACKGROUND

Management of furcation defects is still a challenging subject in periodontal therapy. Drynaria fortunei (Df) is a common type of traditional Chinese herb in the area of orthopedics and traumatology. In vitro and tissue engineering studies have shown that Df induces osteoblastic proliferation and promotes the differentiation of human periodontal ligament cells. This study investigated the management of Class II furcation defects in dogs using guided tissue regeneration (GTR) and Df granules mixed with β-tricalcium phosphate (β- TCP) alloplast.

METHODS

Sixteen Class II critical-sized furcation defects were surgically created in four mongrel dogs: Eight defects were treated with GTR and Df granules mixed with (β-TCP) alloplast served as the experimental group, while the other eight were managed with GTR and alloplast, served as control. Dogs were sacrificed at 4 and 8 weeks and the premolars were processed for the evaluation of treatment outcome including; osteoblastic count (OC), cementum layer thickness (CLT), percentage of collagen in bone matrix (CBM), and alkaline phosphatase (ALP) immunoreaction.

RESULTS

Experimental group treated with Df showed a significant increase (P < 0.001) in the values of OC, CLT, CBM, and ALP immunoreactivity when compared with control at 4 and 8 weeks after treatment.

CONCLUSION

Drynaria fortunei demonstrated increased regeneration and bone formation when used in the treatment of furcation defects in a canine model.

Natural graft tissues and synthetic biomaterials for periodontal and alveolar bone reconstructive applications: a review

Periodontal disease is categorized by the destruction of periodontal tissues. Over the years, there have been several clinical techniques and material options that been investigated for periodontal defect repair/regeneration. The development of improved biomaterials for periodontal tissue engineering has significantly improved the available treatment options and their clinical results. Bone replacement graft materials, barrier membranes, various growth factors and combination of these have been used. The available bone tissue replacement materials commonly used include autografts, allografts, xenografts and alloplasts. These graft materials mostly function as osteogenic, osteoinductive and/or osteoconductive scaffolds. Polymers (natural and synthetic) are more widely used as a barrier material in guided tissue regeneration (GTR) and guided bone regeneration (GBR) applications. They work on the principle of epithelial cell exclusion to allow periodontal ligament and alveolar bone cells to repopulate the defect before the normally faster epithelial cells. However, in an attempt to overcome complications related to the epithelial down-growth and/or collapse of the non-rigid barrier membrane and to maintain space, clinicians commonly use a combination of membranes with hard tissue grafts. This article aims to review various available natural tissues and biomaterial based bone replacement graft and membrane options used in periodontal regeneration applications.

Effects of beta-tricalcium phosphate particles on primary cultured murine dendritic cells and macrophages

Beta-tricalcium phosphate (β-TCP) is widely used for bone substitution in clinical practice. Particles of calcium phosphate ceramics including β-TCP act as an inflammation mediators, which is an unfavorable characteristic for a bone substituent or a prosthetic coating material. It is thought that the stimulatory effect of β-TCP on the immune system could be utilized as an immunomodulator. Here, in vitro effects of β-TCP on primary cultured murine dendritic cells (DCs) and macrophages were investigated. β-TCP particles enhanced expression of costimulatory surface molecules, including CD86, CD80, and CD40 in DCs, CD86 in macrophages, and MHC class II and class I molecules in DCs. DEC205 and CCR7 were up-regulated in β-TCP-treated DCs. Production of cytokines and chemokines, including CCL2, CCL3, CXCL2, and M-CSF, significantly increased in DCs; CCL2, CCL3, CCL4, CCL5, CXCL2, and IL-11ra were up-regulated in macrophages. The results of the functional assays revealed that β-TCP caused a prominent reduction in antigen uptake by DCs, and that conditioned medium from DCs treated with β-TCP facilitated the migration of splenocytes in the transwell migration assay. Thus, β-TCP induced phenotypical and functional maturation/activation of DCs and macrophages; these stimulating effects may contribute to the observed in vivo effect where β-TCP induced extensive migration of immune cells. When compared to lipopolysaccharide (LPS), an authentic TLR ligand, the stimulatory effect of β-TCP on the immune systems is mild to moderate; however, it may have some advantages as a novel immunomodulator. This is the first report on the direct in vitro effects of β-TCP against bone marrow-derived DCs and macrophages.

Clinical Evaluation of Insulin like Growth Factor-I and Vascular Endothelial Growth Factor with Alloplastic Bone Graft Material in the Management of Human Two Wall Intra-Osseous Defects

INTRODUCTION

In recent years, emphasis on the use of growth factors for periodontal healing is gaining great momentum. Several growth factors showed promising results in periodontal regeneration.

AIM

This study was designed to compare the clinical outcomes of 0.8μg recombinant human Vascular Endothelial Growth Factor (rh-VEGF) and 10μg recombinant human Insulin Like Growth Factor-I (rh-IGF-I) with β-Tricalcium Phosphate (β-TCP) and Polylactide-Polyglycolide Acid (PLGA) membrane in two wall intra-osseous defects.

MATERIALS AND METHODS

A total of 29 intra-osseous defects in 27 subjects were randomly divided into 3 test and 1 control group. Test group I (n=8) received rh-VEGF+ rh-IGF-I, Test group II (n=7) rh-VEGF, Test group III (n=7) rh-IGF-I and control group (n=7) with no growth factor, β-TCP and PLGA membrane was used in all the groups. Baseline soft tissue parameters including Probing Pocket Depth (PPD), Clinical Attachment Level (CAL), and Gingival Recession (GR) at selected sites were recorded at baseline and at 6 months. Intrasurgically, intra-osseous component was calculated as a) Cemento-Enamel Junction to Bone Crest (CEJ to BC), b) Bone Crest to Base of the Defect (BC to BD) at baseline and at re-entry. The mean changes at baseline and after 6 months within each group were compared using Wilcoxon Signed Rank Test. The mean changes for each parameter between groups were compared using Mann-Whitney U test.

RESULTS

After 6 months, maximum mean PPD reduction occurred in test group I followed by test group II, III and control group. Similar trend was observed in CAL gain. Non-significant GR was present in test group I and control group whereas in test group II and III GR was absent. The use of rh-VEGF+ rhIGF-I exhibited 95.8% osseous fill as compared to 54.8% in test group II, 52.7% in test group III and 41.1 % in the control group.

CONCLUSION

Within the limitations of this study, it can be concluded that, rh-IGF-I+rh-VEGF treated sites resulted in greater improvement in PPD reduction, CAL gain as well as in osseous fill after 6 months when compared with rh-VEGF, rh-IGF-I and control sites.

Emerging regenerative approaches for periodontal reconstruction: a systematic review from the AAP Regeneration Workshop

More than 30 years have passed since the first successful application of regenerative therapy for treatment of periodontal diseases. Despite being feasible, periodontal regeneration still faces numerous challenges, and complete restoration of structure and function of the diseased periodontium is often considered an unpredictable task. This review highlights developing basic science and technologies for potential application to achieve reconstruction of the periodontium. A comprehensive search of the electronic bibliographic database PubMed was conducted to identify different emerging therapeutic approaches reported to influence either biologic pathways and/or tissues involved in periodontal regeneration. Each citation was assessed based on its abstract, and the full text of potentially eligible reports was retrieved. Based on the review of the full papers, their suitability for inclusion in this report was determined. In principle, only reports from scientifically well-designed studies that presented preclinical in vivo (animal studies) or clinical (human studies) evidence for successful periodontal regeneration were included. Hence, in vitro studies, namely those conducted in laboratories without any live animals, were excluded. In case of especially recent and relevant reviews with a narrow focus on specific regenerative approaches, they were identified as such, and thereby the option of referring to them to summarize the status of a specific approach, in addition to or instead of listing each separately, was preserved. Admittedly, the presence of subjectivity in the selection of studies to include in this overview cannot be excluded. However, it is believed that the contemporary approaches described in this review collectively represent the current efforts that have reported preclinical or clinical methods to successfully enhance regeneration of the periodontium. Today's challenges facing periodontal regenerative therapy continue to stimulate important research and clinical development, which, in turn, shapes the current concept of periodontal tissue engineering. Emerging technologies--such as stem cell therapy, bone anabolic agents, genetic approaches, and nanomaterials--also offer unique opportunities to enhance the predictability of current regenerative surgical approaches and inspire development of novel treatment strategies.

Growth factors and beta-tricalcium phosphate in the treatment of periodontal intraosseous defects: A systematic review and meta-analysis of randomised controlled trials

OBJECTIVE

To evaluate the effectiveness at different points in time, of recombinant human platelet-derived growth factor-BB (rhPDGF-BB) coated onto a beta-tricalcium phosphate (β-TCP) carrier compared to β-TCP alone, or to recombinant human growth/differentiation factor-5 (rhGDF-5) adsorbed onto a β-TCP scaffold in intraosseous periodontal defects.

DESIGN

A digital search for randomised controlled trials (RCTs) was conducted on MEDLINE/PubMed. The quality of reporting and the risk of bias of the included RCTs were assessed using the CONSORT guidelines and the Cochrane risk of bias tool. The difference between the means of the outcomes at baseline and at follow-up for each group was tested using the Student's t-test for paired samples. The difference between the means of the outcome changes at follow-up between groups was analysed using the Student's t-test for two independent samples. Prior to each analysis a test of homogeneity of variances (Ansari-Bradley) was performed.

RESULTS

From 11 articles assessed for eligibility, 5 RCTs were included in this review. The risk of bias was considered to be low in 2 articles, medium in 1 study and high in 2 studies.

CONCLUSIONS

In the treatment of periodontal intraosseous defects the application of rhPDGF-BB/β-TCP improved all outcomes when compared to β-TCP at 6 months follow-up. Either rhPDGF-BB/β-TCP or rhGDF-5/β-TCP seemed to provide similar results in terms of probing pocket depth (PPD) reduction and clinical attachment level (CAL) gain. The application of rhGDF-5/β-TCP resulted in a more pronounced reduction in gingival recession (GR) depth at 6 months follow-up compared to rhPDGF-BB/β-TCP.

Incorporation of aligned PCL-PEG nanofibers into porous chitosan scaffolds improved the orientation of collagen fibers in regenerated periodontium

The periodontal ligament (PDL) is a group of highly aligned and organized connective tissue fibers that intervenes between the root surface and the alveolar bone. The unique architecture is essential for the specific physiological functionalities of periodontium. The regeneration of periodontium has been extensively studied by researchers, but very few of them pay attention to the alignment of PDL fibers as well as its functionalities. In this study, we fabricated a three-dimensional multilayered scaffold by embedding highly aligned biodegradable poly (ε-caprolactone)-poly(ethylene glycol) (PCE) copolymer electrospun nanofibrous mats into porous chitosan (CHI) to provide topographic cues and guide the oriented regeneration of periodontal tissue. In vitro, compared with random group and porous control, aligned nanofibers embedded scaffold could guide oriented arrangement and elongation of cells with promoted infiltration, viability and increased periodontal ligament-related genes expression. In vivo, aligned nanofibers embedded scaffold showed more organized arrangement of regenerated PDL nearly perpendicular against the root surface with more extensive formation of mature collagen fibers than random group and porous control. Moreover, higher expression level of periostin and more significant formation of tooth-supporting mineralized tissue were presented in the regenerated periodontium of aligned scaffold group. Incorporation of aligned PCE nanofibers into porous CHI proved to be applicable for oriented regeneration of periodontium, which might be further utilized in regeneration of a wide variety of human tissues with a specialized direction.

STATEMENT OF SIGNIFICANCE

The regeneration of periodontium has been extensively studied by researchers, but very few of them give attention to the alignment of periodontal ligament (PDL) fibers as well as its functionalities. The key issue is to provide guidance to the orientation of cells with aligned arrangement of collagen fibers perpendicular against the root surface. This study aimed to promote oriented regeneration of periodontium by structural mimicking of scaffolds. The in vitro and in vivo performances of the scaffolds were further evaluated to test the topographic-guiding and periodontium healing potentials. We also think our research may provide ideas in regeneration of a wide variety of human tissues with a specialized direction.

Targeting gene expression during the early bone healing period in the mandible: A base for bone tissue engineering

PURPOSE

Although bone tissue engineering techniques have become more and more sophisticated than in the past, natural bone healing mechanisms have not been sufficiently considered for further improvement of these techniques so far. We used an established animal model with transcriptome analysis to generate an unbiased picture of early bone healing to support tissue engineering concepts.

MATERIAL AND METHODS

In 30 Wistar rats, a 3-mm bone defect was created in the mandibular angle. Tissue was sampled at 5, 10, and 15 days, and the former defect area was excised to undergo transcriptome analysis after RNA extraction. Five differentially expressed genes were further evaluated with reverse transcription-polymerase chain reaction (rt-PCR).

RESULTS

Transcriptome analysis revealed 2467 significantly over- and under-expressed transcripts after 5 days and 2265 after 15 days of bone healing, respectively. Validation via rt-PCR confirmed overexpression of osteoactivin, angiopoietin-like factor-4, and metallomatrix proteinase-9 and underexpression of mastcellprotease-10 and proteoglycane-2 in comparison to values in the control group.

CONCLUSION

This systematic genome-wide transcriptome analysis helps to decipher the physiological mechanisms behind physiological bone healing. The exemplary depiction of 5 genes demonstrates the great complexity of metabolic processes during early bone healing. Here, BMP-2 signaling pathways and local hypoxia play decisive roles in bone formation.

3D Printing of Octacalcium Phosphate Bone Substitutes

Biocompatible calcium phosphate ceramic grafts are able of supporting new bone formation in appropriate environment. The major limitation of these materials usage for medical implants is the absence of accessible methods for their patient-specific fabrication. 3D printing methodology is an excellent approach to overcome the limitation supporting effective and fast fabrication of individual complex bone substitutes. Here, we proposed a relatively simple route for 3D printing of octacalcium phosphates (OCP) in complexly shaped structures by the combination of inkjet printing with post-treatment methodology. The printed OCP blocks were further implanted in the developed cranial bone defect followed by histological evaluation. The obtained result confirmed the potential of the developed OCP bone substitutes, which allowed 2.5-time reducing of defect's diameter at 6.5 months in a region where native bone repair is extremely inefficient.

Wound models for periodontal and bone regeneration: the role of biologic research

The ultimate goals of periodontal therapy remain the complete regeneration of those periodontal tissues lost to the destructive inflammatory-immune response, or to trauma, with tissues that possess the same structure and function, and the re-establishment of a sustainable health-promoting biofilm from one characterized by dysbiosis. This volume of Periodontology 2000 discusses the multiple facets of a transition from therapeutic empiricism during the late 1960s, toward regenerative therapies, which is founded on a clearer understanding of the biophysiology of normal structure and function. This introductory article provides an overview on the requirements of appropriate in vitro laboratory models (e.g. cell culture), of preclinical (i.e. animal) models and of human studies for periodontal wound and bone repair. Laboratory studies may provide valuable fundamental insights into basic mechanisms involved in wound repair and regeneration but also suffer from a unidimensional and simplistic approach that does not account for the complexities of the in vivo situation, in which multiple cell types and interactions all contribute to definitive outcomes. Therefore, such laboratory studies require validatory research, employing preclinical models specifically designed to demonstrate proof-of-concept efficacy, preliminary safety and adaptation to human disease scenarios. Small animal models provide the most economic and logistically feasible preliminary approaches but the outcomes do not necessarily translate to larger animal or human models. The advantages and limitations of all periodontal-regeneration models need to be carefully considered when planning investigations to ensure that the optimal design is adopted to answer the specific research question posed. Future challenges lie in the areas of stem cell research, scaffold designs, cell delivery and choice of growth factors, along with research to ensure appropriate gingival coverage in order to prevent gingival recession during the healing phase.

Introduction of a mixture of β-tricalcium phosphate into a complex of bone marrow mesenchymal stem cells and type I collagen can augment the volume of alveolar bone without impairing cementum regeneration

BACKGROUND

The purpose of this study is to evaluate whether β-tricalcium phosphate (β-TCP) could be a promising modality to help augment alveolar bone in periodontal tissue regeneration by bone marrow mesenchymal stem cells (BMMSCs).

METHODS

Expanded BMMSCs and atelocollagen (Col) were mixed together (MSC/Col). A combination of β-TCP with MSC/Col was also prepared (MSC/Col/TCP). MSC/Col/TCP or MSC/Col was transplanted into experimental periodontal Class III furcation defects that had been exposed to inflammation in beagle dogs. Periodontal tissue regeneration was evaluated by histologic and morphometric analyses at 4 and 8 weeks after transplantation.

RESULTS

MSC/Col and MSC/Col/TCP enhanced periodontal tissue regeneration compared to Col and TCP/Col according to hematoxylin and eosin staining. The percentage of new cementum length in the MSC/Col/TCP group was not significantly different from that in the MSC/Col group at 4 and 8 weeks. On the other hand, the percentage of new bone area in the MSC/Col/TCP group was much higher than that in the MSC/TCP group at 4 weeks. However, at 8 weeks, no significant difference in new bone area was found between the two groups. In the MSC/Col/TCP group, β-TCP was surrounded by newly formed bone. Multinucleated cells, which were positive for osteopontin and tartrate-resistant acid phosphatase, were present in the interconnected macropores of β-TCP.

CONCLUSION

These findings suggest that β-TCP is applicable as a scaffold for BMMSCs transplantation and helps augment alveolar bone without impairing regeneration of cementum.

Biomimetic ceramics for periodontal regeneration in infrabony defects: A systematic review

Biomimetic materials are widely used in the treatment of osseous defects as an alternative to autogenous bone graft. The aim of this article was to review the literature and compare the quality of published articles on biomimetic ceramic material used for periodontal regeneration in the treatment of infrabony defects and to discuss the future direction of research. The bibliographic databases PubMed, Ebsco, and Google Scholar were searched from January 2000 to March 2014 for randomized control trials in which biomimetic ceramic graft material was compared with open flap debridement or in combination with any other regenerative material. To avoid the variability of the search terms, the thesaurus Mesh was used. The primary outcome variable assessed was clinical attachment level (CAL). The screening of eligible studies, assessment of the methodological quality of the trials, and data extraction were performed by two observers independently. Twenty-six articles were identified and included in this systematic review. The primary outcome was CAL. Out of the 26 studies, 24 showed more than 2 mm of CAL gain. The difference in CAL change between test and control groups varied from 1.2 mm to 5.88 mm with respect to different biomaterials/biomimetic materials, which was clinically and statistically significant. Meta-analysis was not done due to heterogeneity in results between studies. Overall, biomaterials were found to be more effective than open flap debridement in improving the attachment levels in intraosseous defects. Future research should aim at increasing the osteoinductive capacity of these biomimetic graft materials.

Bioceramics composed of octacalcium phosphate demonstrate enhanced biological behavior

Bioceramics are used to treat bone defects but in general do not induce formation of new bone, which is essential for regeneration process. Many aspects related to bioceramics synthesis, properties and biological response that are still unknown and, there is a great need for further development. In the most recent research efforts were aimed on creation of materials from biological precursors of apatite formation in humans. One possible precursor is octacalcium phosphate (OCP), which is believed to not only exhibit osteoconductivity but possess osteoinductive quality, the ability to induce bone formation. Here we propose a relatively simple route for OCP ceramics preparation with a specifically designed microstructure. Comprehensive study for OCP ceramics including biodegradation, osteogenic properties in ortopic and heterotopic models and limited clinical trials were performed that demonstrated enhanced biological behavior. Our results provide a possible new concept for the clinical applications of OCP ceramics.

Comparative evaluation of periosteum as a barrier membrane with and without an alloplastic bone graft in periodontal osseous defects: A 9 months follow-up study

BACKGROUND

Regenerative procedures frequently include the use of barrier membranes and bone grafting materials to encourage the growth of key surrounding tissues. The present study aims to evaluate and compare the ability of periosteum in intrabony defect regeneration.

MATERIALS AND METHODS

A total of ten intrabony defects were equally divided in two treatment groups. Group I consisted of Periosteum used as a barrier memebrane and Group II of periosteum as barrier membrane alongwith graft material. Nine months post operative evaluation of defect fill was done radiographically.

RESULTS

Mean defect fill (CEJ-BBD) was found to be significantly lower in Group II as compared to Group I (P = 0.041).

CONCLUSION

Within the limitations of this study, alloplastic graft material supplimentation results in better regeneration with Periosteum used as a barrier membrane.

Bone augmentation using a highly porous PLGA/β-TCP scaffold containing fibroblast growth factor-2

BACKGROUND AND OBJECTIVE

Beta-tricalcium phosphate (β-TCP), a bio-absorbable ceramic, facilitates bone conductivity. We constructed a highly porous three-dimensional scaffold, using β-TCP, for bone tissue engineering and coated it with co-poly lactic acid/glycolic acid (PLGA) to improve the mechanical strength and biological performance. The aim of this study was to examine the effect of implantation of the PLGA/β-TCP scaffold loaded with fibroblast growth factor-2 (FGF-2) on bone augmentation.

MATERIAL AND METHODS

The β-TCP scaffold was fabricated by the replica method using polyurethane foam, then coated with PLGA. The PLGA/β-TCP scaffold was characterized by scanning electron miscroscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction, compressive testing, cell culture and a subcutaneous implant test. Subsequently, a bone-forming test was performed using 52 rats. The β-TCP scaffold, PLGA-coated scaffold, and β-TCP and PLGA-coated scaffolds loaded with FGF-2, were implanted into rat cranial bone. Histological observations were made at 10 and 35 d postsurgery.

RESULTS

SEM and TEM observations showed a thin PLGA layer on the β-TCP particles after coating. High porosity (> 90%) of the scaffold was exhibited after PLGA coating, and the compressive strength of the PLGA/β-TCP scaffold was six-fold greater than that of the noncoated scaffold. Good biocompatibility of the PLGA/β-TCP scaffold was found in the culture and implant tests. Histological samples obtained following implantation of PLGA/β-TCP scaffold loaded with FGF-2 showed significant bone augmentation.

CONCLUSION

The PLGA coating improved the mechanical strength of β-TCP scaffolds while maintaining high porosity and tissue compatibility. PLGA/β-TCP scaffolds, in combination with FGF-2, are bioeffective for bone augmentation.

Biomaterials for periodontal regeneration: a review of ceramics and polymers

Periodontal disease is characterized by the destruction of periodontal tissues. Various methods of regenerative periodontal therapy, including the use of barrier membranes, bone replacement grafts, growth factors and the combination of these procedures have been investigated. The development of biomaterials for tissue engineering has considerably improved the available treatment options above. They fall into two broad classes: ceramics and polymers. The available ceramic-based materials include calcium phosphate (eg, tricalcium phosphate and hydroxyapatite), calcium sulfate and bioactive glass. The bioactive glass bonds to the bone with the formation of a layer of carbonated hydroxyapatite in situ. The natural polymers include modified polysaccharides (eg, chitosan,) and polypeptides (collagen and gelatin). Synthetic polymers [eg, poly(glycolic acid), poly(L-lactic acid)] provide a platform for exhibiting the biomechanical properties of scaffolds in tissue engineering. The materials usually work as osteogenic, osteoconductive and osteoinductive scaffolds. Polymers are more widely used as a barrier material in guided tissue regeneration (GTR). They are shown to exclude epithelial downgrowth and allow periodontal ligament and alveolar bone cells to repopulate the defect. An attempt to overcome the problems related to a collapse of the barrier membrane in GTR or epithelial downgrowth is the use of a combination of barrier membranes and grafting materials. This article reviews various biomaterials including scaffolds and membranes used for periodontal treatment and their impacts on the experimental or clinical management of periodontal defect.

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.

Protein and peptide-based therapeutics in periodontal regeneration

Protein and peptide-based therapeutics provide a unique strategy for controlling highly specific and complex biologic actions that cannot be accomplished by simple devices or chemical compounds. This article reviews some of the key characteristics and summarizes the clinical effectiveness of protein and peptide-based therapeutics targeting periodontal regeneration.

EVIDENCE ACQUISITION

A literature search was conducted of randomized clinical trials and systematic reviews evaluating protein and peptide-based therapeutics for the regeneration of periodontal tissues of at least 6 months duration. Data sources included PubMed and Embase electronic databases, hand-searched journals, and the ClinicalTrials.gov registry.

EVIDENCE SYNTHESIS

Commercially marketed protein and peptide-based therapeutics for periodontal regeneration provide gains in clinical attachment level and bone formation that are comparable or superior to other regenerative approaches. Results from several clinical trials indicate that protein and peptide-based therapies can accelerate repair and regeneration when compared with other treatments and that improvements in clinical parameters continue beyond 12 months. Protein and peptide-based therapies also exhibit the capacity to increase the predictability of treatment outcomes.

CONCLUSIONS

Clinical and histologic studies support the effectiveness of protein- and peptide-based therapeutics for periodontal regeneration. Emerging evidence suggests that the delivery devices/scaffolds play a critical role in determining the effectiveness of this class of therapeutics.

In vitro evaluation of demineralized freeze-dried bone allograft in combination with enamel matrix derivative

BACKGROUND

Preclinical and clinical studies suggest that a combination of enamel matrix derivative (EMD) with demineralized freeze-dried bone allograft (DFDBA) may improve periodontal wound healing and regeneration. To date, no single study has characterized the effects of this combination on in vitro cell behavior. The aim of this study is to test the ability of EMD to adsorb to the surface of DFDBA particles and determine the effect of EMD coating on downstream cellular pathways such as adhesion, proliferation, and differentiation of primary human osteoblasts and periodontal ligament (PDL) cells.

METHODS

DFDBA particles were precoated with EMD or human blood and analyzed for protein adsorption patterns via scanning electron microscopy. Cell attachment and proliferation were quantified using a commercial assay. Cell differentiation was analyzed using real-time polymerase chain reaction for genes encoding Runx2, alkaline phosphatase, osteocalcin, and collagen 1α1, and mineralization was assessed using alizarinred staining.

RESULTS

Analysis of cell attachment revealed no significant differences among control, blood-coated, and EMD-coated DFDBA particles. EMD significantly increased cell proliferation at 3 and 5 days after seeding for both osteoblasts and PDL cells compared to control and blood-coated samples. Moreover, there were significantly higher messenger ribonucleic acid levels of osteogenic differentiation markers, including collagen 1α1, alkaline phosphatase, and osteocalcin, in osteoblasts and PDL cells cultured on EMD-coated DFDBA particles at 3, 7, and 14 days.

CONCLUSION

The results suggest that the addition of EMD to DFDBA particles may influence periodontal regeneration by stimulating PDL cell and osteoblast proliferation and differentiation.

Tissue engineering: A new vista in periodontal regeneration

Tissue engineering is a highly promising field of reconstructive biology that draws on recent advances in medicine, surgery, molecular and cellular biology, polymer chemistry, and physiology. The objective of using tissue engineering as therapeutic application has been to harness its ability to exploit selected and primed cells together with an appropriate mix of regulatory factors, to allow growth and specialization of cells and matrix. The authors reviewed controlled clinical trials which also included histological studies that evaluated the potential of tissue engineering as a clinical tool in regeneration. PubMed/MEDLINE databases were searched for studies up to and including June 2010 to identify appropriate articles. A comprehensive search was designed, and the articles were independently screened for eligibility. Articles with authentic controls and proper randomization and pertaining specifically to their role in periodontal regeneration were included. Studies demonstrated that the periodontal regeneration with the use of combination of tissue engineered products with an osteoconductive matrix improve the beneficial effect of these materials by accelerating cellular in growth and revascularization of the wound site. Studies have suggested the use of rh Platelet-derived growth factor + beta tricalcium phosphate for regeneration of the periodontal attachment apparatus in combination with collagen membranes as an acceptable alternative to connective tissue graft for covering gingival recession defects. The studies concluded that growth factors promote true regeneration of the periodontal attachment apparatus and the use of combination protein therapeutics which is commercially available can provide more predictable, faster, less invasive, less traumatic, and efficient outcome for the patient.

Ten-year results following treatment of intrabony defects with an enamel matrix protein derivative combined with either a natural bone mineral or a β-tricalcium phosphate

BACKGROUND

The purpose of the present study is to evaluate the 10-year results following treatment of intrabony defects treated with an enamel matrix protein derivative (EMD) combined with either a natural bone mineral (NBM) or β-tricalcium phosphate (β-TCP).

METHODS

Twenty-two patients with advanced chronic periodontitis and displaying one deep intrabony defect were randomly treated with a combination of either EMD + NBM or EMD + β-TCP. Clinical evaluations were performed at baseline and at 1 and 10 years. The following parameters were evaluated: plaque index, bleeding on probing, probing depth, gingival recession, and clinical attachment level (CAL). The primary outcome variable was CAL.

RESULTS

The defects treated with EMD + NBM demonstrated a mean CAL change from 8.9 ± 1.5 mm to 5.3 ± 0.9 mm (P <0.001) and to 5.8 ± 1.1 mm (P <0.001) at 1 and 10 years, respectively. The sites treated with EMD + β-TCP showed a mean CAL change from 9.1 ± 1.6 mm to 5.4 ± 1.1 mm (P <0.001) at 1 year and 6.1 ± 1.4 mm (P <0.001) at 10 years. At 10 years two defects in the EMD + NBM group had lost 2 mm, whereas two other defects had lost 1 mm of the CAL gained at 1 year. In the EMD + β-TCP group three defects had lost 2 mm, whereas two other defects had lost 1 mm of the CAL gained at 1 year. Compared with baseline, at 10 years, a CAL gain of ≥3 mm was measured in 64% (i.e., seven of 11) of the defects in the EMD + NBM group and in 82% (i.e., nine of 11) of the defects in the EMD + β-TCP group. No statistically significant differences were found between the 1- and 10-year values in either of the two groups. Between the treatment groups, no statistically significant differences in any of the investigated parameters were observed at 1 and 10 years.

CONCLUSION

Within their limitations, the present findings indicate that the clinical improvements obtained with regenerative surgery using EMD + NBM or EMD + β-TCP can be maintained over a period of 10 years.

A phase IIa randomized controlled pilot study evaluating the safety and clinical outcomes following the use of rhGDF-5/β-TCP in regenerative periodontal therapy

To present the safety profile, the early healing phase and the clinical outcomes at 24 weeks following treatment of human intrabony defects with open flap debridement (OFD) alone or with OFD and rhGDF-5 adsorbed onto a particulate β-tricalcium phosphate (β-TCP) carrier. Twenty chronic periodontitis patients, each with at least one tooth exhibiting a probing depth ≥6 mm and an associated intrabony defect ≥4 mm entered the study. Ten subjects (one defect/patient) were randomized to receive OFD alone (control) and ten subjects OFD combined with rhGDF-5/β-TCP. Blood samples were collected at screening, and at weeks 2 and 24 to evaluate routine hematology and clinical chemistry, rhGDF-5 plasma levels, and antirhGDF-5 antibody formation. Plaque and gingival indices, bleeding on probing, probing depth, clinical attachment level, and radiographs were recorded pre- and 24 weeks postsurgery. Comparable safety profiles were found in the two treatment groups. Neither antirhGDF-5 antibody formation nor relevant rhGDF-5 plasma levels were detected in any patient. At 6 months, treatment with OFD + rhGDF-5/β-TCP resulted in higher but statistically not significant PD reduction (3.7 ± 1.2 vs. 3.1 ± 1.8 mm; p = 0.26) and CAL gain (3.2 ± 1.7 vs. 1.7 ± 2.2 mm; p = 0.14) compared to OFD alone. In the tested concentration, the use of rhGDF-5/β-TCP appeared to be safe and the material possesses a sound biological rationale. Thus, further adequately powered, randomized controlled clinical trials are warranted to confirm the clinical relevance of this new approach in regenerative periodontal therapy. rhGDF-5/β-TCP may represent a promising new techology in regenerative periodontal therapy.

Periodontal regeneration: a challenge for the tissue engineer?

Periodontitis affects around 15 per cent of human adult populations. While periodontal treatment aimed at removing the bacterial cause of the disease is generally very successful, the ability predictably to regenerate the damaged tissues remains a major unmet objective for new treatment strategies. Existing treatments include the use of space-maintaining barrier membranes (guided tissue regeneration), use of graft materials, and application of bioactive molecules to induce regeneration, but their overall effects are relatively modest and restricted in application. The periodontal ligament is rich in mesenchymal stem cells, and the understanding of the signalling molecules that may regulate their differentation has increased enormously in recent years. Applying these principles for the development of new tissue engineering strategies for periodontal regeneration will require further work to determine the efficacy of current experimental preclinical treatments, including pharmacological application of growth factors such as bone morphogenetic proteins (BMPs) or Wnts, use of autologous stem cell reimplantation strategies, and development of improved biomaterial scaffolds. This article describes the background to this problem, addresses the current status of periodontal regeneration, including the background biology, and discusses the potential for some of these experimental therapies to achieve the goal of clinically predictable periodontal regeneration.