Regeneration of periodontal tissues: combinations of barrier membranes and grafting materials - biological foundation and preclinical evidence: A systematic review

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

Background:

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

Materials and Methods:

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

Results:

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

Conclusion:

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

Effects of azithromycin, metronidazole, amoxicillin, and metronidazole plus amoxicillin on an in vitro polymicrobial subgingival biofilm model

Chronic periodontitis is one of the most prevalent human diseases and is caused by dysbiosis of the subgingival microbiota. Treatment involves primarily mechanical disruption of subgingival biofilms and, in certain cases, adjunctive use of systemic antibiotic therapy. In vitro biofilm models have been developed to study antimicrobial agents targeting subgingival species. However, these models accommodate a limited number of taxa, lack reproducibility, and have low throughput. We aimed to develop an in vitro multispecies biofilm model that mimics subgingival plaque, to test antimicrobial agents. Biofilms were cultivated using the Calgary Biofilm Device and were exposed to amoxicillin (AMX), metronidazole (MTZ), azithromycin (AZM), and AMX-MTZ at four different concentrations for 12, 24, or 36 h. Chlorhexidine (CHX) (0.12%) was used as the positive control. The compositions of the biofilms were analyzed by checkerboard DNA-DNA hybridization, and the percent reduction in biofilm metabolic activity was determined using 2,3,5-triphenyltetrazolium chloride and spectrophotometry. Thirty-five of the 40 species used in the inoculum were consistently recovered from the resulting in vitro biofilms. After 36 h of exposure at the 1:27 dilution, AMX-MTZ reduced metabolic activity 11% less than CHX (q = 0.0207) but 54% more than AMX (q = 0.0031), 72% more than MTZ (q = 0.0031), and 67% more than AZM (q = 0.0008). Preliminary evidence of a synergistic interaction between AMX and MTZ was also observed. In summary, we developed reproducible biofilms with 35 subgingival bacterial species, and our results suggested that the combination of AMX and MTZ had greater antimicrobial effects on these in vitro multispecies biofilms than expected on the basis of the independent effects of the drugs.

Electrospun microfiber membranes embedded with drug-loaded clay nanotubes for sustained antimicrobial protection

Guided tissue regeneration/guided bone regeneration membranes with sustained drug delivery were developed by electrospinning drug-loaded halloysite clay nanotubes doped into poly(caprolactone)/gelatin microfibers. Use of 20 wt % nanotube content in fiber membranes allowed for 25 wt % metronidazole drug loading in the membrane. Nanotubes with a diameter of 50 nm and a length of 600 nm were aligned within the 400 nm diameter electrospun fibers, resulting in membranes with doubling of tensile strength along the collector rotating direction. The halloysite-doped membranes acted as barriers against cell ingrows and have good biocompatibility. The metronidazole-loaded halloysite nanotubes incorporated in the microfibers allowed for extended release of the drugs over 20 days, compared to 4 days when directly admixed into the microfibers. The sustained release of metronidazole from the membranes prevented the colonization of anaerobic Fusobacteria, while eukaryotic cells could still adhere to and proliferate on the drug-loaded composite membranes. This indicates the potential of halloysite clay nanotubes as drug containers that can be incorporated into electrospun membranes for clinical applications.

Evaluation of metronidazole-loaded poly(3-hydroxybutyrate) membranes to potential application in periodontitis treatment

Guided tissue regeneration is a technique used for periodontium reconstruction. This technique uses barrier membranes, which prevent epithelial growth in the wound site and may also be used to release antibiotics, to protect the wound against opportunistic infections. Periodontal poly(3-hydroxybutyrate) membranes containing metronidazole (a drug used to help in infection control) were produced and characterized. The kinetic mechanism of the metronidazole delivery of leached and nonleached membrane as well as its cytotoxicity and structural integrity were evaluated. Poly(3-hydroxybutyrate) membranes containing 0.5-2 wt % of the drug and 20 wt % of the plasticizer were manufactured via compression molding. Based on morphological analysis, membranes loaded with 2% metronidazole were considered for detailed studies. The results revealed that metronidazole delivery by the leached membranes seemed to follow the Fick's law. Membranes were noncytotoxic. The amount of metronidazole delivered was in the range of the minimal inhibitory concentration for Porphyromonas gingivalis, and the membranes inhibited the proliferation of these bacteria. Besides, they maintained their mechanical resistance after 30 days of immersion in phosphate buffer at pH 7.4.

Efficacy of Connective Tissue with and without Periosteum in Regeneration of Intrabony Defects

Background and aims. Connective tissue grafts with and without periosteum is used in regenerative treatments of bone and has demonstrated successful outcomes in previous investigations. The aim of present study was to evaluate the effectiveness of connective tissue graft with and without periosteum in regeneration of intrabony defects.

Materials and methods. In this single-blind randomized split-mouth clinical trial, 15 pairs of intrabony defects in 15 patients with moderate to advanced periodontitis were treated by periosteal connective tissue graft + ABBM (test group) or non-periosteal connective tissue graft + ABBM (control group). Probing pocket depth, clinical attachment level, free gingival margin position, bone crestal position, crest defect depth and defect depth to stent were measured at baseline and after six months by surgical re-entry. Data was analyzed by Student’s t-test and paired t-tests (α=0.05).

Results. Changes in clinical parameters after 6 months in the test and control groups were as follows: mean of PPD reduction: 3.1±0.6 (P<0.0001); 2.5±1.0 mm (P<0.0001), CAL gain: 2.3±0.9 (P<0.0001); 2.2±1.0 mm (P<0.0001), bone fill: 2.2±0.7 mm (P<0.0001); 2.2±0.7 mm (P<0.0001), respectively. No significant differences in the position of free gingival margin were observed during 6 months compared to baseline in both groups.

Conclusion. Combinations of periosteal connective tissue graft + ABBM and non-periosteal connective tissue graft + ABBM were similarly effective in treating intrabony defects without any favor for any group. Connective tissue and perio-steum can be equally effective in regeneration of intrabony defects.

Proresolving nanomedicines activate bone regeneration in periodontitis

Therapies to reverse tissue damage from osteolytic inflammatory diseases are limited by the inability of current tissue-engineering procedures to restore lost hard and soft tissues. There is a critical need for new therapeutics in regeneration. In addition to scaffolds, cells, and soluble mediators necessary for tissue engineering, control of endogenous inflammation is an absolute requirement for success. Although significant progress has been made in understanding natural resolution of inflammation pathways to limit uncontrolled inflammation in disease, harnessing the biomimetic properties of proresolving lipid mediators has not been demonstrated. Here, we report the use of nano-proresolving medicines (NPRM) containing a novel lipoxin analog (benzo-lipoxin A4, bLXA4) to promote regeneration of hard and soft tissues irreversibly lost to periodontitis in the Hanford miniature pig. In this proof-of-principle experiment, NPRM-bLXA4 dramatically reduced inflammatory cell infiltrate into chronic periodontal disease sites treated surgically and dramatically increased new bone formation and regeneration of the periodontal organ. These findings indicate that NPRM-bLXA4 is a mimetic of endogenous resolving mechanisms with potent bioactions that offers a new therapeutic tissue-engineering approach for the treatment of chronic osteolytic inflammatory diseases.

Functionalized PCL/HA nanocomposites as microporous membranes for bone regeneration

In the present work, microporous membranes based on poly(ε-caprolactone) (PCL) and PCL functionalized with amine (PCL-DMAEA) or anhydride groups (PCL-MAGMA) were realized by solvent-non solvent phase inversion and proposed for use in Guided Tissue Regeneration (GTR). Nanowhiskers of hydroxyapatite (HA) were also incorporated in the polymer matrix to realize nanocomposite membranes. Scanning Electron Microscopy (SEM) showed improved interfacial adhesion with HA for functionalized polymers, and highlighted substantial differences in the porosity. A relationship between the developed porous structure of the membrane and the chemical nature of grafted groups was proposed. Compared to virgin PCL, hydrophilicity increases for functionalized PCL, while the addition of HA influences significantly the hydrophilic characteristics only in the case of virgin polymer. A significant increase of in vitro degradation rate was found for PCL-MAGMA based membranes, and at lower extent of PCL-DMAEA membranes. The novel materials were investigated regarding their potential as support for cell growth in bone repair using multipotent mesenchymal stromal cells (MSC) as a model. MSC plated onto the various membranes were analyzed in terms of adhesion, proliferation and osteogenic capacity that resulted to be related to chemical as well as porous structure. In particular, PCL-DMAEA and the relative nanocomposite membranes are the most promising in terms of cell-biomaterial interactions.

Evolution of Barrier Membranes in Periodontal Regeneration-"Are the third Generation Membranes really here?"

In the last decades, Guide Tissue Regeneration (GTR) technique has been applied for the treatment of various periodontal defects such as intrabony defects, furcation involvements and localized gingival recession defects. From early days of using membranes with the simple aim of minimizing toxic response in the host, membranes have come a long way. Third generation membranes not only act as barriers but also as delivery devices to release specific agents. Many clinical trials have focused on using membranes as delivery devices for antibiotics and growth factors. In this article we take a brief look at the evolution of barrier membranes and future avenues with regard to third generation membranes.

Bioresorbable zinc hydroxyapatite guided bone regeneration membrane for bone regeneration

OBJECTIVES

The aim of this study was to investigate the bone regenerative properties of a heat treated cross-linked GBR membrane with zinc hydroxyapatite powders in the rat calvarial defect model over a 6-week period.

MATERIAL AND METHODS

In vitro physio-chemical characterization involved X-ray diffraction analysis, surface topology by scanning electron microscopy, and zinc release studies in physiological buffers. Bilateral rat calvarial defects were used to compare the Zn-HAp membranes against the commercially available collagen membranes and the unfilled defect group through radiological and histological evaluation.

RESULTS

The synthesized Zn-MEM (100 μm thick) showed no zinc ions released in the phosphate buffer solution (PBS) buffer, but zinc was observed under acidic conditions. At 6 weeks, both the micro-CT and histological analyses revealed that the Zn-MEM group yielded significantly greater bone formation with 80 ± 2% of bone filled, as compared with 60 ± 5% in the collagen membrane and 40 ± 2% in the unfilled control group.

CONCLUSION

This study demonstrated the use of heat treatment as an alternative method to cross-linking the Zn-MEM to be applied as a GBR membrane. Its synthesis and production are relatively simple to fabricate, and the membrane had rough surface features on one side, which might be beneficial for cellular activities. In a rat calvarial defect model, it was shown that new bone formation was accelerated in comparison with the collagen membrane and the unfilled defect groups. These results would suggest that Zn-MEM has the potential for further development in dental applications.

Calcium phosphate barrier for augmentation of bone in noncontained periodontal osseous defects: a novel approach

AIM

The aim of this technique is to augment bone in non-contained osseous deformities using a unique self-sustaining calcium phosphate barrier.

INTRODUCTION

Bone has the inherent ability to regenerate completely if it is provided with a fracture space or an undisturbed enclosed scaffold. A secluded environment is essential as it provides a secured, sterile and stable wound system that regenerates lost bone by a process of osteopromotion. Reconstructive techniques using bone grafts and barrier membranes utilize this principle for augmentation of deficient bony sites by providing a closed environment that promotes clot stability, graft retention, and facilitates correct cell repopulation. However, in noncontained bone defects like one walled infrabony periodontal defect or sites with horizontal bone loss, regeneration of bone still remains an unrealistic situation since osseous topography at such sites does not favor membrane stability or bone grafts retention. This case report presents a promising technique to augment bone in areas with horizontal loss.

TECHNIQUE

Augmentation of bone in the interdental area with horizontal bone loss was accomplished by building a contained defect using a unique self sustaining calcium phosphate cement formulation. The calcium phosphate barrier stimulates the lost cortical plates and promotes graft retention and clot stability. At 6 months, there was a significant bone fill and trabecular formation in the interdental area and reduction in tooth mobility.

CONCLUSION

This promising technique could prove to be a good alternative to the conventional approaches for treating osseous deformities.

CLINICAL SIGNIFICANCE

Calcium phosphate is a promising barrier graft for repair of noncontained periodontal osseous defect. This technique cues both the clinicians and manufacturers to develop moldable tissue engineered constructs for osseous repair.

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.

Connective tissue graft as a biological barrier for guided tissue regeneration in intrabony defects: a histological study in dogs

BACKGROUND

The use of the autogenous periosteal graft as biological barrier has been proposed for periodontal regeneration. The aim of this study was to evaluate the histometric findings of the subepithelial connective tissue graft as barrier in intrabony defects compared to a bioabsorbable membrane.

METHODS

Three-walled intrabony defects were created surgically in the mesial aspect of the right and left maxillary canines in five healthy mongrel dogs. The defects were chronified, and two types of barriers were randomly carried out for guided tissue regeneration in a split-mouth design: the test group with a subepithelial connective tissue graft and the control group with a bioabsorbable membrane. The specimens were processed for histometric analyses of the epithelium (E), connective tissue (CT), newly formed cementum (NC), new bone (NB), and total newly formed tissues (NFT).

RESULTS

The test side showed smaller mean of NC (3.6 ± 1.2), NB (2.1 ± 0.7), and NFT (7.7 ± 0.8) than the control group (NC 7.3 ± 0.5; NB 5.3 ± 1.3; NFT 10.1 ± 2.2; P < 0.05). No statistically significant differences were verified for E (test 3.1 ± 2.0; control 2.8 ± 2.1; P > 0.05) and CT (test 2.5 ± 1.1; control 2.0 ± 0.5; P > 0.05) between groups.

CONCLUSION

The bioabsorbable membrane was more effective in maintaining the space for periodontal regeneration than periosteal connective graft when used as barrier.

CLINICAL RELEVANCE

The bioabsorbable membrane showed more favorable regenerative results in intrabony defects in dogs than the subepithelial connective tissue graft as biological barrier.

Periodontal regeneration - intrabony defects: a systematic review from the AAP Regeneration Workshop

BACKGROUND

Previous systematic reviews of periodontal regeneration with bone replacement grafts and guided tissue regeneration (GTR) were defined as state of the art for clinical periodontal regeneration as of 2002.

METHODS

The purpose of this systematic review is to update those consensus reports by reviewing periodontal regeneration approaches developed for the correction of intrabony defects with the focus on patient-, tooth-, and site-centered factors, surgical approaches, surgical determinants, and biologics. This review adheres to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for systematic reviews. A computerized search of the PubMed and Cochrane databases was performed to evaluate the clinically available regenerative approaches for intrabony defects. The search included screening of original reports, review articles, and reference lists of retrieved articles and hand searches of selected journals. All searches were focused on clinically available regenerative approaches with histologic evidence of periodontal regeneration in humans published in English. For topics in which the literature is lacking, non-randomized observational and experimental animal model studies were used. Therapeutic endpoints examined included changes in clinical attachment level, changes in bone level/fill, and probing depth. For purposes of analysis, change in bone fill was used as the primary outcome measure, except in cases in which this information was not available. The SORT (Strength of Recommendation Taxonomy) grading scale was used in evaluating the body of knowledge.

RESULTS

1) Fifty-eight studies provided data on patient, tooth, and surgical-site considerations in the treatment of intrabony defects. 2) Forty-five controlled studies provided outcome analysis on the use of biologics for the treatment of intrabony defects.

CONCLUSIONS

1) Biologics (enamel matrix derivative and recombinant human platelet-derived growth factor-BB plus β-tricalcium phosphate) are generally comparable with demineralized freeze-dried bone allograft and GTR and superior to open flap debridement procedures in improving clinical parameters in the treatment of intrabony defects. 2) Histologic evidence of regeneration has been demonstrated with laser therapy; however, data are limited on clinical predictability and effectiveness. 3) Clinical outcomes appear most appreciably influenced by patient behaviors and surgical approach rather than by tooth and defect characteristics. 4) Long-term studies indicate that improvements in clinical parameters are maintainable up to 10 years, even in severely compromised teeth, consistent with a favorable/good long-term prognosis.

Drug loaded homogeneous electrospun PCL/gelatin hybrid nanofiber structures for anti-infective tissue regeneration membranes

Infection is the major reason for guided tissue regeneration/guided bone regeneration (GTR/GBR) membrane failure in clinical application. In this work, we developed GTR/GBR membranes with localized drug delivery function to prevent infection by electrospinning of poly(ε-caprolactone) (PCL) and gelatin blended with metronidazole (MNA). Acetic acid (HAc) was introduced to improve the miscibility of PCL and gelatin to fabricate homogeneous hybrid nanofiber membranes. The effects of the addition of HAc and the MNA content (0, 1, 5, 10, 20, 30, and 40 wt.% of polymer) on the properties of the membranes were investigated. The membranes showed good mechanical properties, appropriate biodegradation rate and barrier function. The controlled and sustained release of MNA from the membranes significantly prevented the colonization of anaerobic bacteria. Cells could adhere to and proliferate on the membranes without cytotoxicity until the MNA content reached 30%. Subcutaneous implantation in rabbits for 8 months demonstrated that MNA-loaded membranes evoked a less severe inflammatory response depending on the dose of MNA than bare membranes. The biodegradation time of the membranes was appropriate for tissue regeneration. These results indicated the potential for using MNA-loaded PCL/gelatin electrospun membranes as anti-infective GTR/GBR membranes to optimize clinical application of GTR/GBR strategies.

Additive effect of autologous platelet concentrates in treatment of intrabony defects: a systematic review and meta-analysis

The aim of the present review is to systematically evaluate the additive effect of autologous platelet concentrates (APCs) in treatment of intrabony defects when used along with other regenerative procedures and when used alone in terms of clinical and radiological outcomes. A search was performed in electronic databases (i.e., MEDLINE and the Cochrane Central Register of Controlled Trials) in order to identify randomized clinical trials (RCTs) assessing the additive efficacy of APCs for healing and regeneration of hard and soft tissues in patients undergoing regenerative surgical procedures for the treatment of intrabony defects, having a follow-up of at least 9 months. Included studies underwent risk of bias assessment and data extraction. The main variables evaluated for efficacy were: pocket depth (PD), clinical attachment level (CAL), radiographic bone filling, and postoperative pain. The effect of APCs adjunct was evaluated for the following procedures: open flap debridement (OFD) alone, OFD plus grafting of the defect with autogenous bone or bone substitutes, and grafting in combination with a covering membrane for guided tissue regeneration (GTR). Platelet-rich fibrin (PRF) has a significant additive effect when used along with OFD. Platelet-rich plasma (PRP) has a significant additive effect when used along with bone grafts. Conversely, PRP was found to be ineffective when used in combination with GTR procedures. No study evaluated the effect of APCs on postoperative pain. Platelet-rich plasma may be used advantageously as an adjunct to grafting materials, but not in combination with GTR, for treatment of intrabony defects. Moreover, PRF can be effective as a sole regenerative material, in combination with OFD. There is still a lack of evidence regarding the effect of PRF in combination with grafting materials and GTR, the effect of other types of APCs such as plasma rich in growth factors, and the effect of APCs on postoperative pain.

Comparative study of NMP-preloaded and dip-loaded membranes for guided bone regeneration of rabbit cranial defects

Guided bone regeneration (GBR) has been utilized for several decades for the healing of cranio-maxillofacial bone defects and, particularly in the dental field, by creating space with a barrier membrane to exclude soft tissue and encourage bone growth in the membrane-protected volume. Although the first membranes were non-resorbable, a new generation of GBR membranes aims to biodegrade and provide bioactivity for better overall results. The Inion GTR™ poly(lactide-co-glycolide) (PLGA) membrane is not only resorbable but also bioactive, since it includes N-methylpyrrolidone (NMP), which has been shown to promote bone regeneration. In this study, the effects of loading different amounts of NMP onto the membrane through chemical vapour deposition or dipping have been explored. In vitro release demonstrated that lower levels of NMP led to lower NMP concentrations and slower release, based on total NMP loaded in the membrane. The dipped membrane released almost all of the NMP within 15 min, leading to a high NMP concentration. For the in vivo studies in rabbits, 6 mm calvarial defects were created and left untreated or covered with an ePTFE membrane or PLGA membranes dipped in, or preloaded with, NMP. Evaluation of the bony regeneration revealed that the barrier membranes improved bony healing and that a decrease in NMP content improved the performance. Overall, we have demonstrated the potential of these PLGA membranes with a more favourable NMP release profile and the significance of exploring the effect of NMP on these PLGA membranes with regard to bone ingrowth. Copyright © 2014 John Wiley & Sons, Ltd.

Non-cross-linked collagen type I/III materials enhance cell proliferation: in vitro and in vivo evidence

Objective

To analyze Mucograft^®(MG), a recently introduced collagen matrix, in vitro and in vivo, and compare it with BioGide^®(BG), a well-established collagen membrane, as control.

Material and Methods

A detailed analysis of the materials surface and ultra-structure was performed. Cellular growth patterns and proliferation rates of human fibroblasts on MG and BG were analyzed in vitro. In addition, the early tissue reaction of CD-1 mouse to these materials was analyzed by means of histological and histomorphometrical analysis.

Results

MG showed a three-fold higher thickness both in dry and wet conditions, when compared to BG. The spongy surface of BG significantly differed from that of MG. Cells showed a characteristic proliferation pattern on the different materials in vitro. Fibroblasts tended to proliferate on the compact layers of both collagens, with the highest values on the compact side of BG. In vivo, at day three both materials demonstrated good tissue integration, with a mononuclear cell sheet of fibroblasts on all surfaces, however, without penetrating into the materials.

Conclusions

The findings of this study showed that MG and BG facilitate cell proliferation on both of their surfaces in vitro. In vivo, these two materials induce a comparable early tissue reaction, while serving as cell occlusive barriers.

Clinical outcomes following regenerative therapy of non-contained intrabony defects using a deproteinized bovine bone mineral combined with either enamel matrix derivative or collagen membrane

BACKGROUND

The purpose of this study is to compare clinical outcomes in the treatment of deep non-contained intrabony defects (i.e., with ≥70% 1-wall component and a residual 2- to 3-wall component in the most apical part) using deproteinized bovine bone mineral (DBBM) combined with either enamel matrix protein derivative (EMD) or collagen membrane (CM).

METHODS

Forty patients with multiple intrabony defects were enrolled. Only one non-contained defect per patient with an intrabony depth ≥3 mm located in the interproximal area of single- and multirooted teeth was randomly assigned to the treatment with either EMD + DBBM (test: n = 20) or CM + DBBM (control: n = 20). At baseline and after 12 months, clinical parameters including probing depth (PD) and clinical attachment level (CAL) were recorded. The primary outcome variable was the change in CAL between baseline and 12 months.

RESULTS

At baseline, the intrabony component of the defects amounted to 6.1 ± 1.9 mm for EMD + DBBM and 6.0 ± 1.9 mm for CM + DBBM sites (P = 0.81). The mean CAL gain at sites treated with EMD + DBBM was not statistically significantly different (P = 0.82) compared with CM + DBBM (3.8 ± 1.5 versus 3.7 ± 1.2 mm). No statistically significant difference (P = 0.62) was observed comparing the frequency of CAL gain ≥4 mm between EMD + DBBM (60%) and CM + DBBM (50%) or comparing the frequency of residual PD ≥6 mm between EMD + DBBM (5%) and CM + DBBM (15%) (P = 0.21).

CONCLUSION

Within the limitations of the present study, regenerative therapy using either EMD + DBBM or CM + DBBM yielded comparable clinical outcomes in deep non-contained intrabony defects after 12 months.

A novel porcine collagen GTR membrane for treatment of Class II molar furcation involvement

Guided tissue regeneration (GTR) in the management of the periodontal furcation invasion is effective. Recent studies showed significant clinical improvement with different materials. The purpose of this study is to provide clinical evaluations of the bone repair potential of GTR combined with a novel porcine collagen membrane in the treatment of human molar Class II furcations. Fifty-one patients, 33 males and 18 females, with no systemic disease and a mean age of 49.1 years, participated in this study after phase I periodontal therapy. Probing depth, attachment loss and radiographic examination were recorded and analyzed before and after GTR therapy with collagen membrane. In the soft tissue measurement, the periodontal pocket (PD) depth was 5.283±0.283 mm before the surgery and improved to 2.631±0.147 mm at 9 months after surgery (p<0.05). Attachment loss also showed similar results. The attachment level was 5.547±0.3 mm before the surgery, and 2.911±0.188 mm at 9 months after surgery (p<0.05). According to the measurements the attachment gain was 2.636±0.168 mm after GTR surgery with porcine collagen membrane. According to this study, the porcine collagen membrane can perform with exceptional results in attachment level gain for the Class II periodontal furcation involvement.

Regenerative periodontal therapy: 30 years of lessons learned and unlearned

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

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.

Analysis of human alveolar osteoblast behavior on a nano-hydroxyapatite substrate: an in vitro study

BACKGROUND

Nano-hydroxyapatite (nHA) is a potential ideal biomaterial for bone regeneration. However, studies have yet to characterize the behavior of human osteoblasts derived from alveolar bone on nHA. Thus, the aim of the present study was to evaluate the influence of nHA on the adhesion, proliferation and differentiation of these alveolar bone-derived cells.

METHODS

Primary human alveolar osteoblasts were collected from the alveolar ridge of a male periodontal patient during osseous resective surgery and grown on culture plates coated with either polylysine or polylysine with nano-hydroxyapatite (POL/nHA) composite. The cells were grown and observed for 14 days, and then assessed for potential modifications to osteoblasts homeostasis as evaluated by quantitative reverse transcriptase-polymerase chain reaction (real time RT-PCR), scanning electron microscopy and atomic force microscopy.

RESULTS

Real time PCR revealed a significant increase in the expression of the selected markers of osteoblast differentiation (bone morphogenetic protein (BMP)-2,-5,-7, ALP, COLL-1A2, OC, ON) in cells grown on the POL/nHA substrate. In addition, as compared with the POL surface, cells grown on the POL/nHA substrate demonstrated better osteoconductive properties, as demonstrated by the increase in adhesion and spreading, likely as a result of the increased surface roughness of the composite.

CONCLUSIONS

The increased expression of BMPs and osteoinductive biomarkers suggest that nano-hydroxyapatite may stimulate the proliferation and differentiation of local alveolar osteoblasts and thus encourage bone regeneration at sites of alveolar bone regeneration.

Clinical outcomes after treatment of periodontal intrabony defects with nanocrystalline hydroxyapatite (Ostim) or enamel matrix derivatives (Emdogain): a randomized controlled clinical trial

Introduction. Periodontitis is an inflammatory process in response to dental biofilm and leads to periodontal tissue destruction. The aim of this study was the comparison of outcomes using either an enamel matrix derivative (EMD) or a nanocrystalline hydroxyapatite (NHA) in regenerative periodontal therapy after 6 and 12 months. Methods. Using a parallel group, prospective randomized study design, we enrolled 19 patients in each group. The primary outcome was bone fill after 12 months. Attachment gain, probing pocket depth (PPD) reduction, and recession were secondary variables. Additionally, early wound healing and adverse events were assessed. Data analysis included test of noninferiority of NHA group (test) compared to EMD group (reference) in bone fill. Differences in means of secondary variables were compared by paired t-test, frequency data by exact χ² test. Results. Both groups showed significant bone fill, reduction of PPD, increase in recession, and gain of attachment after 6 and 12 months. No significant differences between groups were found at any time point. Adverse events were comparable between both groups with a tendency of more complaints in the NHA group. Conclusion. The clinical outcomes were similar in both groups. EMD could have some advantage compared to NHA regarding patients comfort and adverse events. The trial is registered with ClinicalTrials.gov NCT00757159.

Platelet rich fibrin - a novel acumen into regenerative endodontic therapy

Research into regenerative dentistry has added impetus onto the field of molecular biology. It can be documented as a prototype shift in the therapeutic armamentarium for dental disease. Regenerative endodontic procedures are widely being added to the current armamentarium of pulp therapy procedures. The regenerative potential of platelets has been deliberated. A new family of platelet concentrates called the platelet rich fibrin (PRF) has been recently used by several investigators and has shown application in diverse disciplines of dentistry. This paper is intended to add light on the various prospects of PRF and clinical insights to regenerative endodontic therapy.

[Ridge preservation with synthetic nanocrystalline hydroxyapatite reduces the severity of gingival invaginations-a prospective clinical study]

BACKGROUND AND OBJECTIVE

Gingival invaginations develop after tooth extraction and subsequent orthodontic space closure. Aetiological factors and long-term effects of gingival invaginations on oral health are nearly unknown. In addition, preventive or therapeutic strategies are rare. This prospective clinical study employing the split mouth technique was performed to investigate the effect of extraction socket augmentation with a synthetic nanocrystalline hydroxyapatite (NanoBone(®) Artoss, Rostock, Germany) on the incidence and degree of gingival invaginations.

MATERIAL AND METHODS

A total of 10 orthodontic patients with need for symmetric premolar extractions offering a total of 28 extractions were included in this trial. The study plan provided one extraction site to be augmented with synthetic nanocrystalline hydroxyapatite (NanoBone(®)), the other served as control. After primary wound healing, space closure was performed under defined biomechanical conditions. After space closure was accomplished, occurrence and degree of gingival invaginations as well as probing depths of the adjacent teeth mesial and distal to the extractions were determined and dental radiographs were taken.

RESULTS

The degree of gingival invaginations and probing depths mesial and distal of the extraction were significantly reduced on NanoBone(®) augmented extraction sites. In addition, 70% of the radiographs revealed translucent and hyperdense areas on the intervention side after space closure. Apical root resorption was found in 2 patients on both the NanoBone(®) side and the control side.

CONCLUSION

Ridge preservation with NanoBone(®) appeared to reduce the severity of gingival invaginations. Further investigation on long-term effects is mandatory to eliminate the appearance of adverse effects.

The association of hydrogel and biphasic calcium phosphate in the treatment of dehiscence-type peri-implant defects: an experimental study in dogs

Hydrogel polymers have many applications in regenerative medicine. The aim of this study in dogs was to investigate bone regeneration in dehiscence-type peri-implant defects created surgically and treated with (i) biphasic calcium phosphate (BCP) granules alone; (ii) a composite putty hydroxypropyl methylcellulose (HPMC)/BCP (MBCP/putty); and (iii) a polymer crosslinked membrane of silanized-HPMC (Si-HPMC/BCP) compared with empty controls. At 3 months, new bone formation was significantly more important in defects filled with HPMC/BCP or Si-HPMC/BCP compared with spontaneous healing in control (P = 0.032 and P = 0.046 respectively) and more substantial compared with BCP alone. Furthermore, new bone formation in direct contact with the implant surface was observed in all three groups treated with BCP. The addition of HPMC to the BCP granules may have enhanced the initial stability of the material within the blood clot in these large and complex osseous defects. The Si-HPMC hydrogel may also act as an occlusive membrane covering the BCP, which could improve the stability of the granules in the defect area. However, the crosslinking time of the Si-HPMC is too long for easy handling and the mechanical properties remain to be improved. The composite MBCP/putty appears to be a valuable bone-graft material in complex defects in periodontology and implantology. These encouraging results should now be confirmed in clinical studies.

Comparison of treatment effects of guided tissue regeneration on infrabony lesions between animal and human studies: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

For ethical reasons it is becoming increasingly more difficult to obtain, from clinical studies, histological data on infrabony defects treated with guided tissue regeneration (GTR) techniques. The aim of this systematic review was to find the value of extrapolating animal data on treatment of periodontal infrabony lesions, using GTR only or GTR + bone grafts, to human clinical results.

MATERIAL AND METHODS

Searches of the PubMed and Cochrane databases were combined with hand searching of articles published from 1 January 1969 to 1 August 2012. The search included any type of barrier membrane, with or without grafted materials, used to treat periodontal infrabony lesions. All studies with histological or re-entry methodology outcome parameters that evaluated bone-filling and/or new-cementum-formation ratios from a defect depth were collected. When comparing animal and human outcomes, a meta-analysis was used to evaluate the bone-filling ratio, but only a descriptive analysis of the histological studies was performed.

RESULTS

In total, 22 studies were selected for the meta-analysis. In the GTR + bone graft groups the weighted-average bone-filling ratios were 52% (95% CI: 18-85%) in animals and 57% (95% CI: 30-83%) in humans, which were not statistically significantly different (p = 0.825). Similar results were found in the GTR-only groups, in which the weighted-average bone-filling ratios were 54% (95% CI: 37-72%) in animals and 59% (95% CI: 42-77%) in humans (p = 0.703). New-cementum formation of GTR only and GTR + bone grafts showed comparable ratio outcomes, and both were superior to the control group in animals only (p = 0.042).

CONCLUSION

Although quality assessments differed between animal and human studies, our analysis indicated that animal models and human results showed similar bone-filling ratios in infrabony defects treated with GTR only or with GTR + bone grafting.

Effect of pulverized natural bone mineral on regeneration of three-wall intrabony defects. A preclinical study

AIMS

The objective of this study is to evaluate the effects of a paste-like bone substitute material with easy handling properties and improved mechanical stability on periodontal regeneration of intrabony defects in dogs.

MATERIALS AND METHODS

Mandibular and maxillary first and third premolars were extracted, and three-wall intrabony defects were created on second and fourth premolars. After a healing period of 3 months, acute type defects were filled with a paste-like formulation of deproteinized bovine bone mineral (DBBM) (particle size, 0.125-0.25 mm) in a collagenous carrier matrix (T1), pulverized DBBM (particle size, 0.125-0.25 mm) without the carrier (T2), or Bio-Oss® granules (particle size, 0.25-1.00 mm) as control (C). All defects were covered with a Bio-Gide® membrane. The dogs were sacrificed after 12 weeks, and the specimens were analyzed histologically and histometrically.

RESULTS

Postoperative healing of all defects was uneventful, and no histological signs of inflammation were observed in the augmented and gingival regions. New cementum, new periodontal ligament, and new bone were observed in all three groups. The mean vertical bone gain was 3.26 mm (T1), 3.60 mm (T2), and 3.81 mm (C). That of new cementum was 2.25 mm (T1), 3.88 mm (T2), and 3.53 mm (C). The differences did not reach statistical significance. The DBBM particles were both incorporated in new bone and embedded in immature bone marrow.

CONCLUSIONS

The results of this preclinical study showed that the 0.125-0.25-mm DBBM particles in a powder or paste formulation resulted in periodontal regeneration comparable to the commercially available DBBM. Osteoconductivity, in particular, was not affected by DBBM size or paste formulation.

CLINICAL RELEVANCE

The improved handling properties of the paste-like bone substitute consisting of small DBBM particles embedded in a collagen-based carrier hold promise for clinical applications.

AB, O'Connell PA, Grisi MFM, Taba Jr. M, Palioto DB, Souza SLS. Effect of Early Membrane Removal on the Treatment of Mandibular Class II Furcation Defects - A Controlled Clinical Trial with Re-entry after 12 Months

In a previous study in dogs, the early removal of expanded polytetrafluoroethylene (ePTFE) membrane (2 weeks after placement) showed histomorphometric results (of new bone, cementum and periodontal ligament) similar to that obtained with membrane removal at 4 weeks after placement. This study evaluated the influence of early removal of an ePTFE membrane on the treatment of Class II furcation defects. Twelve patients who provided 12 pairs of mandibular furcation defects were recruited for the study. Baseline clinical measurements were recorded: plaque index (PI), gingival index (GI), bleeding on probing (BOP), probing depth (PD), gingival margin position (GMP) and relative clinical attachment level (RCAL). Full flaps were elevated and hard tissue measurements were performed during the surgery: relative vertical (RVBL) and horizontal (RHBL) bone level. The ePTFE membranes were adapted and sutured to their correspondent tooth and removed at 2 weeks in the test group (TGr) and at 4 weeks in the control group (CGr). After 1 year all sites were re-entered, and soft and hard tissue measurements were recorded. There were no statistically significant differences between TGr and CGr for any baseline measurement. After 12 months, there were no statistically significant differences between TGr and CGr in the PD (p=0.74), GMP (p=0.76) and RCAL (p=0.44) values. However, the RHBL resolution was significant for both groups (CGr p=0.01 and TGr p=0.02), without difference between groups (p=0.39). Early removal of membranes did not affect the outcome on the treatment of Class II furcation defects.

Surgical Approaches Based on Biological Objectives: GTR versus GBR Techniques

Guided tissue regenerative (GTR) therapies are performed to regenerate the previously lost tooth supporting structure, thus maintaining the aesthetics and masticatory function of the available dentition. Alveolar ridge augmentation procedures (GBR) intend to regain the alveolar bone lost following tooth extraction and/or periodontal disease. Several biomaterials and surgical approaches have been proposed. In this paper we report biomaterials and surgical techniques used for periodontal and bone regenerative procedures. Particular attention will be adopted to highlight the biological basis for the different therapeutic approaches.

Comparative Study of Human Dental Follicle Cell Sheets and Periodontal Ligament Cell Sheets for Periodontal Tissue Regeneration

Periodontal ligament cell (PDLC) sheets have been shown to contribute to periodontal tissue regeneration. Dental follicle cells (DFCs), acknowledged as the precursor cells of PDLCs, have demonstrated stemness, embryonic features, heterogeneity, and pluripotency. Therefore, we hypothesized that DFC sheets might be more effective and suitable for periodontal tissue regeneration than PDLC sheets. In this study, we compared the biological characteristics of DFC sheets and PDLC sheets in vitro. To investigate the potential for periodontal tissue regeneration in vivo, complexes composed of two types of cell sheets combined with dentin matrix were implanted subcutaneously into nude mice for 6 weeks. Our results showed that, when forming cell sheets, DFCs secreted richer extracellular matrix than PDLCs. And compared to DFCs, DFC sheets expressed high levels of calcification-related genes, including alkaline phosphatase ( alp), bone sialoprotein ( bsp), osteopontin ( opn), runt-related transcription factor ( runx2), as well as the periodontal ligament-specific genes collagen III ( col III) and periostin, while the gene expression of bsp, osteocalcin ( ocn), and opn were greatly increased in PDLC sheets, when compared to PDLCs. col I expression did not change significantly. However, cementum protein 23 ( cp-23) expression increased several fold in PDLC sheets compared to PDLCs but decreased in DFC sheets compared to DFCs. DFC and PDLC sheets were both positive for Collagen I (Col I), cementum attachment protein (CAP), ALP, BSP, OCN, and OPN protein expression, and Col I, ALP, BSP, and OPN expression were increased after cell sheets were formed. Furthermore, the levels of laminin and fibronectin were higher in DFCs and DFC sheets than that of PDLCs and PDLC sheets, respectively. In vivo, DFC and PDLC sheets could both regenerate periodontal tissue-like structures, but DFC sheets demonstrated stronger periodontal regeneration potential than PDLC sheets. Therefore, DFC sheets derived from discarded dental follicle tissue after tooth extraction may be more advantageous for clinical periodontal tissue regeneration in the future.

Combination of platelet rich fibrin, hydroxyapatite and PRF membrane in the management of large inflammatory periapical lesion

Periapical inflammatory lesion is the local response of bone around the apex of tooth that develops after the necrosis of the pulp tissue or extensive periodontal disease. The final outcome of the nature of wound healing after endodontic surgery can be repair or regeneration depending on the nature of the wound; the availability of progenitor cells; signaling molecules; and micro-environmental cues such as adhesion molecules, extracellular matrix, and associated non-collagenous protein molecules. The purpose of this case report is to add knowledge to the existing literature about the combined use of graft material [platelet rich fibrin (PRF) and hydroxyapatite (HA)] and barrier membrane in the treatment of large periapical lesion. A periapical endodontic surgery was performed on a 45 year old male patient with a swelling in the upper front teeth region and a large bony defect radiologically. The surgical defect was filled with a combination of PRF and HA bone graft crystals. The defect was covered by PRF membrane and sutured. Clinical examination revealed uneventful wound healing. Radiologically the HA crystals have been completely replaced by new bone at the end of 2 years. On the basis of the results obtained in our case report, we hypothesize that the use of PRF in conjunction with HA crystals might have accelerated the resorption of the graft crystals and would have induced the rapid rate of bone formation.

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

Aim:

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

Materials and Methods:

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

Results:

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

Conclusion:

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

Effect of basic fibroblast growth factor (FGF-2) in combination with beta tricalcium phosphate on root coverage in dog

OBJECTIVE

In root coverage treatment, periodontal regeneration in gingival recession-type defects is an important challenge for the periodontist. The aim of this study was to histometrically investigate the effect of combined use of basic fibroblast growth factor (FGF-2) and beta tricalcium phosphate (β-TCP) on root coverage in dogs.

MATERIALS AND METHODS

Sixteen adult beagle dogs were used. Buccal gingival recession defects were surgically created bilaterally in the maxillary canines. The defects in each animal were randomly assigned to: (1) an FGF-2 alone (control) group or (2) FGF-2/β-TCP (experimental) group. At 2, 4 or 8 weeks following surgery, specimens were obtained and subjected to microscopic examination and histometric assessment.

RESULTS

Inhibition of epithelial down-growth was observed in both groups. At week 2, in the newly formed connective tissue at the coronal portion, the FGF-2/β-TCP group showed significantly greater numbers of proliferating cell nuclear antigen-positive cells than the FGF-2 group (55.8 ± 4.8 vs 12.0 ± 1.4, p < 0.01). In the FGF-2/β-TCP group, new attachment was observed at 8 weeks and the extent of new bone and cementum formation was significantly greater in the FGF-2/β-TCP group than that in the FGF-2 alone group. In both groups, the dentin surface beneath the new cementum presented minor irregularities, but no replacement resorption was observed.

CONCLUSIONS

FGF-2 used in combination with β-TCP enhances formation of new bone and cementum without significant root resorption in root coverage in this dog model. This combination warrants further investigation in periodontal regeneration in root coverage treatment.

Incorporation of stromal cell-derived factor-1α in PCL/gelatin electrospun membranes for guided bone regeneration

The goal of this work was to evaluate the effect of membrane functionalization with a chemotactic factor on cell recruitment and bone formation in order to develop a bioactive membrane for guided bone regeneration (GBR) applications. To this end, GBR membranes were prepared by electrospinning using poly(ε-caprolactone) (PCL) blended with type B-gelatin, and functionalized with stromal cell derived factor-1α (SDF-1α) via physical adsorption. Firstly, the obtained membranes were evaluated in vitro for SDF-1α release and chemotactic effect on bone marrow stromal cells (BMSCs). Subsequently, in vivo BMSCs recruitment and bone regeneration in response to SDF-1α loaded PCL/gelatin electrospun membranes were assessed in rat cranial defects. The results showed that PCL/gelatin electrospun membranes provided a diffusion-controlled SDF-1α release profile. Furthermore, the membranes loaded with different amounts of SDF-1α (50-400 ng) significantly induced stimulated chemotactic migration of BMSCs in vitro without dose-dependent effects. Eight weeks after implantation in rat cranial defects, SDF-1α loaded membranes yielded a 6-fold increase in the amount of bone formation compared to the bare membranes, albeit that contribution of in vivo BMSCs recruitment to the bone regeneration could not be ascertained. In conclusion, the results of current study indicate the potential for using SDF-1α loaded PCL/gelatin electrospun membrane as a bioactive membrane, which is beneficial for optimizing clinical application of GBR strategies.

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

Background:

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

Materials and Methods:

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

Results:

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

Conclusion:

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