Histologic evaluation of new attachment apparatus formation in humans. Part III

Autogenous platelet concentrates for treatment of intrabony defects-A systematic review with meta-analysis

To provide an overview of the use of autogenous platelet concentrates (APCs) in periodontal regeneration and to conduct a systematic review (SR) of the treatment outcomes of periodontal intrabony defects by using platelet-rich fibrin (PRF) compared with other commonly utilized modalities. The eligibility criteria comprised randomized controlled trials (RCTs) comparing the clinical outcomes of PRF with that of other modalities. Studies were classified into 21 categories and into five different groups as follows: Group I (1) open flap debridement (OFD) alone versus OFD/PRF, (2) OFD versus Titanium-PRF (T-PRF) Group II, (3) Comparative PRF protocols (PRF vs. T-PRF), Group III (Comparative Studies to PRF): (4) OFD/PRP versus OFD/PRF, (5) OFD/bone graft(BG)/PRGF versus OFD/BG/PRF, (6) OFD/EMD versus OFD/PRF, (7) OFD/BG/EMD versus OFD/BG/PRF, (8) OFD/collagen membrane (CM) versus OFD/PRF, (9) OFD/BG/BM versus OFD/BG/PRF, (10) OFD/BG versus OFD/PRF, Group IV (Addition of PRF to treatment groups) (11) OFD/BG versus OFD/BG/PRF, (12) OFD/GTR versus OFD/GTR + PRF (13) OFD/EMD versus OFD/EMD/PRF (14) OFD/BG/BM versus OFD/BG/BM/PRF, Group V (Addition of Biomaterial/Biomolecule to PRF): OFD/PRF versus … (15) OFD/PRF/BG, (16) OFD/PRF/antibiotic, (17) OFD/PRF/Metformin, (18) OFD/PRF/Bisphosphonates, (19) OFD/PRF/Statins, (20) OFD/BG/PRF versus OFD/BG/PRF/Statins, and (21) OFD/PRF/low-level laser therapy (LLLT). Weighted means and forest plots were calculated for probing pocket depth (PPD), clinical attachment level (CAL), and radiographic bone fill (RBF). From 596 records identified, 55 RCTs were included. Group I: The use of OFD/PRF statistically significantly reduced PPD and improved CAL and RBF when compared to OFD. Group II: A significant difference between various PRF protocols was only observed for PPD. Group III: No significant advantage was found when comparing OFD/PRF to the following groups: OFD/PRP, OFD/EMD, OFD/BM, or OFD/BG. Group IV: The addition of PRF to OFD/BG led to significant improvements in PPD, CAL and RBF compared with OFD/BG alone. Group V: The addition of either a BG as well as three of the following biomolecules (metformin, bisphosphonates, and statins) to OFD/PRF led to statistically significant improvements in PPD, CAL, and/or RBF when compared to OFD/PRF alone. The use of PRF significantly improved clinical outcomes in intrabony defects when compared to OFD alone. Similar results were observed when OFD/PRF was compared with OFD/BG, OFD/EMD, OFD/PRP, and OFD/BM. The addition of PRF to a bone grafting material as well as the addition of various small biomolecules to PRF may offer additional clinical advantages, thus warranting further investigations. Future research investigating various protocols of PRF, longer-term outcomes, as well as PRF at the human histological level remains needed.

A Comparative Evaluation of Advanced Platelet-Rich Fibrin Combined With Demineralized Freeze-Dried Bone Allograft and Demineralized Freeze-Dried Bone Allograft Alone in the Treatment of Periodontal Infrabony Defects: A Clinical and Radiographic Study

Aim Allografts, autografts, alloplast and xenografts are frequently used for periodontal regeneration. The aim of this study was to determine the efficacy of advanced platelet-rich fibrin (A-PRF) in combination with demineralized freeze-dried bone allograft (DFDBA) and DFDBA alone in periodontal infrabony defects. Methodology This was a split-mouth design study where 20 infrabony defects in 10 patients were included. Patients were randomly divided into two groups, where DFDBA allograft and A-PRF were used in the test group, while the DFDBA allograft alone was used in the control group. Furthermore, the results were evaluated at baseline, three, and nine months, respectively, in terms of clinical and radiographic parameters. Data were analysed with an unpaired t-test at the significance level of P < 0.05 (statistically significant). Results Both treatments showed reduced clinical and radiographic parameters from baseline to nine months. There was a non-significant difference in the plaque index (PI), bleeding on probing (BOP), clinical attachment level (CAL), and radiographic defect fill (RDF). In comparison to the control group (3.40 ± 0.516), the probing pocket depth (PPD) in the test group at nine months (3.22 ± 0.422) was statistically significant showing reduction in the PPD (P = 0.042). Conclusion Within its limitations, the study showed that A-PRF plus DFDBA and DFDBA alone treatment modalities reduced clinical and radiographic parameters from baseline, at 9 months; however, the inclusion of A-PRF did not substantially improve the treatment outcome when comparing both the groups, except for the probing pocket depth after nine months.

Osseous topography in biologically driven flap design in minimally invasive regenerative therapy: A classification proposal

Minimally invasive periodontal regenerative surgical procedures are a paradigm shift that demands a unique approach encompassing specialized armamentarium, magnification tools, knowledge of handling properties of biomaterials, and specific flap designs. Biologically driven flap design is dictated by optimal soft and hard tissue handling, flap perfusion, and wound stability, all in the pursuit of primary intention healing. The unique architecture of the infrabony defect is a determining factor on incision tracing, boundaries of flap extension, and biomaterial selection. The purpose of this article is to propose a flap design classification based on the osseous topography of infrabony defects during biologically driven minimally invasive surgical periodontal regenerative therapy.

Tooth preservation vs. extraction and implant placement in periodontally compromised patients: A systematic review and analysis of studies

PURPOSE

The aim of this systematic review was to identify studies with a minimum of 5-years follow-up, reporting on the management of periodontally compromised teeth with either extraction and subsequent implant placement or teeth preservation with conventional periodontal treatment and application of regenerative procedures. The outcomes of these two approaches, based on clinical and radiographic data and the incidence of tooth- and implant-loss, were also investigated.

MATERIAL AND METHODS

A systematic search for studies reporting on clinical and radiographic outcomes of periodontal treatment or replacement of periodontally compromised teeth with implants was conducted in 3 electronic databases, followed by a hand-search in 8 journals. Only randomized controlled trials (RCTs), cohort studies, and case series with prospective design were included.

RESULTS

The initial search resulted in 1080 papers. After the first two screenings, 24 publications were selected for inclusion in this systematic review. The treatment protocols for the teeth preservation group contained nonsurgical and/or surgical periodontal treatment with or without regeneration procedures. The implant studies included extraction of periodontally involved teeth and implant placement with or without bone and soft tissue augmentation, followed by restoration with fixed dental prostheses (FDPs). Survival rates ranged between 81.8% and 100% in the tooth retention group, and between 94.8% and 100% in the implant group. In the extraction group, no complications were reported for 76.09% of the implants. Similarly, no complications were reported for 86.83% of the tooth retention group. The lack of standardized comparable studies prohibited conduction of a metaanalysis.

CONCLUSION

Both treatment approaches, treatment of periodontally compromised teeth, or tooth extraction followed by implant placement, present high survival rates. The application of bone regeneration techniques improves the long-term prognosis of periodontally involved teeth. Hence, treatment of periodontally involved teeth with subsequent application of a rigorous maintenance protocol can be a viable alternative for a number of years, before proceeding to extraction and replacement with dental implants. More well-designed randomized controlled trials are needed in order to draw definite conclusions on the subject.

The Use of Biocompatible Membranes in Oral Surgery: The Past, Present & Future Directions. A Narrative Review

The use of biocompatible membranes in periodontal and oral surgery is an important part of regeneration. Over the years, several different membranes have been developed, ranging from non-resorbable membranes that have to be removed in a separate procedure, to collagen membranes that completely resorb on their own, thus avoiding the need for a second surgery. Autogenous membranes are becoming increasingly popular in more recent years. These membranes can be used with a great variety of techniques in the four main hard tissue regenerative procedures: guided tissue regeneration, alveolar ridge preservation, guided bone regeneration and sinus floor augmentation. A review of the literature was conducted in order to identify the most commonly used membranes in clinical practice, as well as the most promising ones for regeneration procedures in the future. The information provided in this review may serve as a guide to clinicians, in order to select the most applicable membrane for the clinical case treated as the correct choice of materials may be critical in the procedure's success.

Clinical and radiographic evaluation of demineralized freeze-dried bone allograft with concentrated growth factor versus concentrated growth factor alone in the treatment of intrabony defects

BACKGROUND

Periodontal disease is one of the major causes of alveolar bone loss. There are various ways of regenerating the lost bone, i.e. guided tissue regeneration, bone grafts, and growth factors. In this purview, it becomes immensely important for a clinician to decide the best modality of treatment. In this study, we compared the effect of demineralized freeze-dried bone allograft (DFDBA) in combination with concentrated growth factors (CGF) verses CGF alone.

METHODS

This double-blind, split-mouth study was conducted on ten patients with two comparable bilateral intrabony defects. Each pair of defects was randomly treated by DFDBA + CGF or CGF alone. Clinical parameters such as plaque index (PI), modified gingival index (MGI), pocket probing depth (PPD), and relative attachment level (RAL) were recorded at baseline, three months, and six months. In addition, radiograph with grids was also taken at baseline and six months. The paired t-test was used to compare the pre- and post-treatment values and the unpaired t-test was used to compare the test and control group.

RESULTS

The PI score decreased significantly from baseline to six months. Similarly, the mean MGI score decreased significantly from baseline to six months. The intragroup comparison showed that there was a significant reduction in PPD in both the test and control group. However, the intergroup comparison showed that the reduced pocket depth was not significant. The intragroup radiographic comparison showed that there was the significant formation of bone in both the test and control group but inter-group showed that the formation of bone among both the group were non-significant.

CONCLUSION

Radiographic and clinical outcomes of this study concluded that post six months, both groups demonstrated significant improvement in clinical and radiographic parameters. However, the addition of DFDBA to CGFs did not give any additional benefits.

Cyclodextrin-Based Supramolecular Complexes of Osteoinductive Agents for Dental Tissue Regeneration

Oral tissue regeneration has received growing attention for improving the quality of life of patients. Regeneration of oral tissues such as alveolar bone and widely defected bone has been extensively investigated, including regenerative treatment of oral tissues using therapeutic cells and growth factors. Additionally, small-molecule drugs that promote bone formation have been identified and tested as new regenerative treatment. However, treatments need to progress to realize successful regeneration of oral functions. In this review, we describe recent progress in development of regenerative treatment of oral tissues. In particular, we focus on cyclodextrin (CD)-based pharmaceutics and polyelectrolyte complexation of growth factors to enhance their solubility, stability, and bioactivity. CDs can encapsulate hydrophobic small-molecule drugs into their cavities, resulting in inclusion complexes. The inclusion complexation of osteoinductive small-molecule drugs improves solubility of the drugs in aqueous solutions and increases in vitro osteogenic differentiation efficiency. Additionally, various anionic polymers such as heparin and its mimetic polymers have been developed to improve stability and bioactivity of growth factors. These polymers protect growth factors from deactivation and degradation by complex formation through electrostatic interaction, leading to potentiation of bone formation ability. These approaches using an inclusion complex and polyelectrolyte complexes have great potential in the regeneration of oral tissues.

Bone Regeneration of Maxillary Molar Proximal Class 2 Furcation Defects Treated With Microscope-Assisted Papilla Preservation Technique and DFDBA: A Case Series

INTRODUCTION

Periodontal regeneration of maxillary molar proximal furcation defects are challenging due to limited access. While combination therapy of open flap debridement with barrier membrane, bone graft, and biologics are reported to be more successful than monotherapeutic approaches, combination therapy can be complicated and costly.

CASE PRESENTATION

A total of four teeth in three patients are presented to demonstrate radiographic bone regeneration of deep Class 2 maxillary molar proximal furcation defects (MMPFD) treated with microscope-assisted papilla preservation technique (PPT) and demineralized freeze-dried bone allograft (DFDBA).

CONCLUSION(S)

Radiographic bone regeneration of deep Class 2 MMPFD is possible with microscope-assisted PPT and DFDBA. Furthermore, treatment outcomes appear to be superior to those from previous clinical trials of Class 2 MMPFD treatment.

Experimental and clinical studies on regenerative periodontal therapy

The recognition of a periodontal therapy as a regenerative procedure requires the demonstration of new cementum, periodontal ligament, and bone coronal to the base of the defect. A diversity of regenerative strategies has been evaluated, including root surface conditioning, bone grafts and bone substitute materials, guided tissue regeneration, enamel matrix proteins, growth/differentiation factors, combined therapies and, more recently, tissue-engineering approaches. The aim of this chapter of Periodontology 2000 is to review the research carried out in Latin America in the field of periodontal regeneration, focusing mainly on studies using preclinical models (animal models) and randomized controlled clinical trials. This review may help clinicians and researchers to evaluate the current status of the therapies available and to discuss the challenges that must be faced in order to achieve predictable periodontal regeneration in clinical practice.

Bone-implant-contact and new bone formation around implants placed in FDB blocks compared to placement at the adjunction of particulate FDB

BACKGROUND

The efficacy of human freeze-dried bone (h-FDB) as particulate vs block forms as a proper onlay augmented bone graft material to accommodate implants is undetermined.

PURPOSE

To evaluate osseointegration and new bone formation at implants placed in FDB blocks (BL group) and those at the adjunction of particulate FDB (PR group).

MATERIALS AND METHODS

Twelve pairs of h-FDB blocks were stabilized bilaterally to the calvaria of 12 rabbits. Twenty-four SLA implants were placed at the remodeled grafted blocks, 4 months later. A circumferential gap was created around one implant in each pair and packed with particulate h-FDB. Section biopsies were obtained at 2-month post implant placement (6 months post-block grafting). Bone-to-implant contact (BIC) and bone-area fraction (BAF) were histomorphometrically calculated.

RESULTS

The mean BIC was 34.4% and 33.5% for the BL and PR groups, respectively. The mean BAF was 23.9% and 26.4% for the corresponding groups, respectively. Osseointegration and newly formed bone were evident mostly between the threaded portions of the implants in proximity to the host rabbit calvaria compared to its cervical neck.

CONCLUSION

The particulate and the cancellous block h-FDB forms yielded similar BIC and BAF outcome. Full revascularization/revitalization is questioned.

Treatment of extraoral submental sinus tract associated with large periapical lesion of traumatized lower central incisors teeth by periapical surgery and demineralized freeze-dried bone allograft

The purpose of present case report was to observe the effect of demineralized freeze-dried bone allograft (DFDBA) when combined with periapical surgery for the treatment of extraoral submental sinus tract associated with large periapical lesion of traumatized lower central incisors teeth. A patient complains of extraoral submental draining sinus tract since 6 months due to trauma of lower central incisors teeth 1 year back. Radiographical investigation showed large periapical lesion associated with lower central incisors teeth. The patient was planned for treatment by periapical surgery and DFDBA. The treatment process includes elevation of full-thickness flap, debridement of periapical lesion, root canal treatment, defect fill with DFDBA, and suturing of full-thickness flap at its original position. Complete resolution of extraoral submental sinus tract was achieved after 1 week, and periapical lesion was repaired after 1 year. Thus, DFDBA was effective for the treatment of extraoral submental sinus tract associated with large periapical lesion of traumatized lower central incisors teeth.

* Extracellular Matrices for Bone Regeneration: A Literature Review

The gold standard material for bone regeneration is still autologous bone, a mesenchymal tissue that consists mainly of extracellular matrix (ECM) (90% v/v) and little cellular content (10% v/v). However, the fact that decellularized allogenic bone grafts often present a clinical performance comparable to autologous bone grafts demonstrates the crucial role of ECM in bone regeneration. For long, the mechanism by which bone allografts function was not clear, but recent research has unveiled many unique characteristics of ECM that seem to play a key role in tissue regeneration. This is further confirmed by the fact that synthetic biomaterials with composition and properties resembling bone ECM present excellent bone regeneration properties. In this context, ECM molecules such as glycosaminoglycans (GAGs) and self-assembly peptides (SAPs) can improve the performance of bone regeneration biomaterials. Moreover, decellularized ECM derived either from native tissues such as bone, cartilage, skin, and tooth germs or from cells such as osteoblasts, chondrocytes, and stem cells has shown promising results in bone regeneration applications. Understanding the role of ECM in bone regeneration is crucial for the development of the next generation of biomaterials for bone tissue engineering. In this sense, this review addresses the state-of-the-art on this subject matter.

Treatment of Periradicular Bone Defect by Periosteal Pedicle Graft as a Barrier Membrane and Demineralized Freeze-Dried Bone Allograft

The purpose of this case report is to describe the usefulness of Periosteal Pedicle Graft (PPG) as a barrier membrane and Demineralized Freeze-Dried Bone Allograft (DFDBA) for bone regeneration in periradicular bone defect. A patient with intraoral discharging sinus due to carious exposed pulp involvement was treated by PPG and DFDBA. Clinical and radiological evaluations were done immediately prior to surgery, three months, six months and one year after surgery. Patient was treated using split-thickness flap, PPG, apicoectomy, defect fill with DFDBA and lateral displacement along with suturing of the PPG prior to suturing the flap, in order to close the communication between the oral and the periapical surroundings through sinus tract opening. After one year, successful healing of periradicular bone defect was achieved. Thus, PPG as a barrier membrane and DFDBA have been shown to have the potential to stimulate bone formation when used in periradicular bone defect.

Mandibular Degree II Furcation Defects Treatment With Platelet-Rich Fibrin and 1% Alendronate Gel Combination: A Randomized Controlled Clinical Trial

BACKGROUND

Different materials have been investigated for renewal of lost supporting periodontal structures and tested for furcation defect treatment. Platelet-rich fibrin (PRF) is a pool of growth-promoting factors and cytokines that promote bone regeneration and maturation of soft tissue. Alendronate (ALN), an influential member of the bisphosphonate group, is known to enhance osteoblastogenesis and inhibit osteoclastic bone resorption, thus promoting tissue regeneration. This randomized trial was done to assess effectiveness of PRF and 1% ALN gel combination in mandibular degree II furcation defect treatment in comparison with PRF and access therapy alone.

METHODS

Seventy-two mandibular molar furcation defects were treated with either access therapy alone (group 1), access therapy with PRF (group 2), or access therapy with PRF and 1% ALN (group 3). Plaque index, modified sulcus bleeding index, probing depth (PD), relative vertical attachment level (RVAL) and relative horizontal attachment level (RHAL), and intrabony defect depth were recorded at baseline and 9 months postoperatively. Radiographically, defect fill, assessed in percentage, was evaluated at baseline, before surgery, and 9 months post-therapy.

RESULTS

Group 3 showed greater PD reduction and RVAL and RHAL gain when compared with groups 1 and 2 postoperatively. Moreover, group 3 sites showed a significantly greater percentage of radiographic defect fill (56.01% ± 2.64%) when compared with group 2 (49.43% ± 3.70%) and group 1 (10.25% ± 3.66%) at 9 months.

CONCLUSIONS

Furcation defect treatment with autologous PRF combined with 1% ALN gel results in significant therapeutic outcomes when compared with PRF and access therapy alone. Combining ALN with PRF has potential for regeneration of furcation defects without any adverse effect on healing process.

Clinical and Radiographic Evaluation of Demineralized Freeze-Dried Bone Allograft Versus Platelet-Rich Fibrin for the Treatment of Periodontal Intrabony Defects in Humans

BACKGROUND

A wide variety of materials have been proposed for treatment of periodontal intrabony defects (IBDs); recently, platelet-rich fibrin (PRF) has been suggested as a grafting material. The aim of this study is to report changes in clinical attachment level (CAL) and bone fill of periodontal IBDs treated with demineralized freeze-dried bone allograft (DFDBA) compared with PRF in humans.

METHODS

Thirty-six patients completed the study protocol. Each patient contributed a single IBD, which was randomized to receive either DFDBA or PRF. Clinical and standardized radiographic data were collected at baseline and 6 months after treatment. Primary outcome measures included: 1) radiographic bone fill as measured from the cemento-enamel junction to base of bony defect and 2) change in CAL.

RESULTS

Both treatment groups had significant gains in CAL as well as bone fill, with no significant differences in outcomes between groups. DFDBA had a mean CAL gain of 1.16 ± 1.33 mm, mean clinical bone fill of 1.53 ± 1.64 mm, and mean radiographic bone fill of 1.14 ± 0.88 mm. PRF had a mean CAL gain of 1.03 ± 0.86 mm, mean clinical bone fill of 1.35 ± 1.60 mm, and mean radiographic bone fill of 1.10 ± 1.01 mm.

CONCLUSION

Treatment of IBDs with either DFDBA or PRF resulted in a significant gain in CAL as well as bone fill after 6 months of healing, with no significant difference between materials.

Bone demineralization with citric acid enhances adhesion and spreading of preosteoblasts

BACKGROUND

Previous studies have demonstrated that bone demineralization can improve consolidation in bone grafts. The biologic mechanisms underlying this phenomenon remain unclear.

METHODS

Twelve adult male guinea pigs were used in this experiment. Forty-five bone samples removed from the calvaria of nine animals were divided in groups (n = 9) according to the time of demineralization with citric acid (50%, pH 1): 15, 30, 90, and 180 seconds and non-demineralized samples (control). Preosteoblasts (MC3T3-E1) were cultured on the bone samples for 24, 48, and 72 hours (n = 3). Fifteen samples removed from the remaining three animals were analyzed by scanning electron microscopy/energy dispersive spectrometry (SEM/EDS) after demineralization (n = 3).

RESULTS

The number of preosteoblasts increased significantly with time in all groups. The bone surface area covered by these cells increased with time, except in the control group. Intragroup differences occurred between 24 and 72 hours (P < 0.05). Samples demineralized for 30 seconds showed greater area covered by preosteoblast cells than for the other times of demineralization in all periods of cell culture (P < 0.05) without a statistically significant difference compared with 15 seconds. SEM/EDS showed diminished content of calcium (Ca) after 15 seconds of demineralization, but the Ca content increased after 180 seconds of demineralization (P < 0.05). The phosphorus (P) amount increased significantly only after 30 seconds of demineralization (P < 0.5). The sulfur (S) content was increased in demineralized samples in relation to non-demineralized ones, reaching the highest level after 90 seconds, when the difference became significant in relation to all the other times of demineralization (P < 0.05). Magnesium (Mg) content did not differ significantly between demineralized and non-demineralized samples.

CONCLUSIONS

Bone surfaces demineralized for 30 seconds increased the spreading of preosteoblasts as well as the surface area covered by these cells. Bone demineralization deserves to be studied in periodontal and maxillofacial regenerative procedures.

Comparative evaluation of the efficacy of synthetic nanocrystalline hydroxyapatite bone graft (Ostim®) and synthetic microcrystalline hydroxyapatite bone graft (Osteogen®) in the treatment of human periodontal intrabony defects: A clinical and denta scan study

Background:

To evaluate the relative efficacy of synthetic nanocrystalline hydroxyapatite (HA) (Ostim^®) and microcrystalline HA (Osteogen^®) bone grafts in the treatment of human periodontal intrabony defects clinically and radiographically through denta scan.

Materials and Methods:

Ten chronic periodontitis patients with bilateral intrabony periodontal defects of ≥2 mm radiographic defect depth below 55 years of age were selected randomly and treated with synthetic nanocrystalline HA (Ostim^®) or synthetic microcrystalline HA (Osteogen^®) bone graft. Clinical parameters including probing depth (PD) and clinical attachment level (CAL) were measured preoperatively and postoperatively at 3 and 6 months for each of the defects using an occlusal acrylic stent. Radiographic parameters were measured with the help of denta scan preoperatively and postoperatively at 6 months.

Results:

At 6 months following therapy, the Osteogen^® group showed a reduction in mean PD from 11.10 ± 1.663 to 8.50 ± 0.850 mm and a change in mean CAL from 6.30 ± 1.160 to 3.40 ± 0.516 mm, whereas in the Ostim^® group, the mean PD decreased from 11.20 ± 0.919 to 8.30 ± 0.823 mm and mean CAL decreased from 6.10 ± 0.738 to 3.30 ± 0.483 mm. At 6 months following therapy, denta scan showed a reduction in mean intrabony defect depth in the Osteogen^® group from 2.54 ± 0.786 to 1.01 ± 0.448 mm, whereas in the Ostim^® group, it was 2.71 ± 0.650 mm to 1.12 ± 0.563 mm.

Conclusion:

It was concluded that both the HA bone grafts produced statistically significant reduction in pocket depth, in the depth of osseous lesion, and a statistically significant gain in attachment level, irrespective of their physico-chemical properties.

Dental pulp stem cells. Biology and use for periodontal tissue engineering

Inflammatory periodontal disease is a major cause of loss of tooth-supporting structures. Novel approaches for regeneration of periodontal apparatus is an area of intensive research. Periodontal tissue engineering implies the use of appropriate regenerative cells, delivered through a suitable scaffold, and guided through signaling molecules. Dental pulp stem cells have been used in an increasing number of studies in dental tissue engineering. Those cells show mesenchymal (stromal) stem cell-like properties including self-renewal and multilineage differentiation potentials, aside from their relative accessibility and pleasant handling properties. The purpose of this article is to review the biological principles of periodontal tissue engineering, along with the challenges facing the development of a consistent and clinically relevant tissue regeneration platform. This article includes an updated review on dental pulp stem cells and their applications in periodontal regeneration, in combination with different scaffolds and growth factors.

Tissue engineered periodontal products

Attainment of periodontal regeneration is a significant clinical goal in the management of advanced periodontal defects arising from periodontitis. Over the past 30 years numerous techniques and materials have been introduced and evaluated clinically and have included guided tissue regeneration, bone grafting materials, growth and other biological factors and gene therapy. With the exception of gene therapy, all have undergone evaluation in humans. All of the products have shown efficacy in promoting periodontal regeneration in animal models but the results in humans remain variable and equivocal concerning attaining complete biological regeneration of damaged periodontal structures. In the early 2000s, the concept of tissue engineering was proposed as a new paradigm for periodontal regeneration based on molecular and cell biology. At this time, tissue engineering was a new and emerging field. Now, 14 years later we revisit the concept of tissue engineering for the periodontium and assess how far we have come, where we are currently situated and what needs to be done in the future to make this concept a reality. In this review, we cover some of the precursor products, which led to our current position in periodontal tissue engineering. The basic concepts of tissue engineering with special emphasis on periodontal tissue engineering products is discussed including the use of mesenchymal stem cells in bioscaffolds and the emerging field of cell sheet technology. Finally, we look into the future to consider what CAD/CAM technology and nanotechnology will have to offer.

Mandibular tori as bone grafts: an alternative treatment for periodontal osseous defects - clinical, radiographic and histologic morphology evaluation

OBJECTIVES

The present study was designed to evaluate the clinical, radiographic and histochemical significance of using the mandibular tori as autogenous bone graft for treatment of intraosseous defects in patients with chronic periodontitis.

MATERIALS AND METHODS

Twenty-eight sites from 14 patients with chronic periodontitis were included in this study. Each patient was treated with split mouth design; one site received torus mandibularis bone graft and the other site received a full-thickness fap alone. Histopathologic assessment was evaluated on removal of torus mandibularis to evaluate its histologic structure and by the end of the study 9 month later. Clinical and radiographic parameters were re-evaluated at 3 months interval for 1 year.

RESULTS

The results of the present study revealed significant gain in the clinical attachment level (CAL) (88.4%, 4.53 ± 0.06 mm) for torus mandibularis sites compared to (39.7%, 2.01 ± 0.04 mm) for full-thickness fap. Moreover, there was a reduction in the probing pocket depth (PPD) of (75.4%, 5.75 ± 0.12 mm) for torus mandibularis sites and (49.6%, 3.73 ± 0.14 mm) for sites treated with a full-thickness fap only; CAL and PPD differences were significant at p-value ≤0.01. Concomitantly, significant radiographic increase in the bone height and density were recorded in the test group.

CONCLUSION

The use of mandibular tori as autogenous bone graft could provide benefits as a periodontal therapeutic modality and enhance regenerative potential of periodontal intraosseous defects.

Periodontal Regeneration - Intrabony Defects: Practical Applications From the AAP Regeneration Workshop

Focused Clinical Question: What are important considerations for selecting a predictable regenerative surgical approach for intrabony defects? Summary: The predictable regeneration of intrabony defects remains an important goal in the management of periodontitis. Clinical and histologic evidence of periodontal regeneration has been shown for multiple regenerative therapies, including bone replacement grafts, guided tissue regeneration, and biologics, when used alone or in combination. Regenerative therapies improve periodontal health, as evidenced by gains in clinical attachment level, reductions in probing depth, and gains in radiographic bone fill. Important patient-related factors (e.g., smoking) and defect/site-related factors (e.g., defect morphology and gingival biotype) can influence the potential to achieve periodontal regeneration. The regeneration of intrabony defects generally becomes more challenging with increasing loss of height, proximity, and number of bony walls. Therefore, combination therapies may be necessary to achieve predictable regeneration. Clinical improvements after regenerative therapy can be maintained over extended periods (≥10 years) with professional maintenance at appropriate intervals and adequate home care. Conclusions: Periodontal regeneration of intrabony defects is possible using a variety of regenerative strategies. Management should be coupled with an effective oral hygiene and supportive periodontal maintenance program for long-term success.

Comparative evaluation of platelet-rich fibrin with demineralized freeze-dried bone allograft in periodontal infrabony defects: A randomized controlled clinical study

INTRODUCTION

Several bone graft materials have been used in the treatment of infrabony defects. Demineralized freeze-dried bone allograft (DFDBA) has been histologically proven to be the material of choice for regeneration. However, platelet-rich fibrin (PRF) has been said to have several properties that aid in healing and regeneration. Hence, this study focuses on the regenerative capacity of PRF when compared with DFDBA.

MATERIALS AND METHODS

A total of 40 sites with intrabony defects were selected and were assigned to the test group (open flap debridement [OFD] and PRF, n = 20) and the control group (OFD + DFDBA, n = 20). At the test sites, two PRF plugs were placed in the intrabony defect after debridement of the site and flap was sutured in place. The parameters measured were probing depth (PD), relative attachment level (RAL), and gingival marginal level (GML). These parameters were measured just before surgery (baseline) and at 6 months postsurgery. The changes in PD, RAL, and GML were analyzed at baseline and postsurgically after 6 months in each group with paired t-test and between the two groups with unpaired t-test.

RESULTS

The mean reduction in PD after 6 months in the test PRF group is 3.67 ± 1.48 mm where in control DFDBA group is 3.70 ± 1.78 mm. Gain in RAL in the test PRF group is 2.97 ± 1.42 mm where in control DFDBA group, it is 2.97 ± 1.54 mm. Gingival margin migrated apically in the test PRF group by 0.43 ± 1.31 mm where in control DFDBA group by 0.72 ± 2.3 mm. It was seen that the differences in terms of PD (P = 0.96), RAL (P = 1.00) and GML (P = 0.62) were not significant.

CONCLUSION

Platelet-rich fibrin has shown significant results after 6 months, which is comparable to DFDBA for periodontal regeneration in terms of clinical parameters. Hence, it can be used in the treatment of intrabony defects.

A clinical and radiological evaluation of the relative efficacy of demineralized freeze-dried bone allograft versus anorganic bovine bone xenograft in the treatment of human infrabony periodontal defects: A 6 months follow-up study

Background:

The ultimate goal of periodontal therapy entails regeneration of the periodontal tissues lost as a consequence of periodontitis. Predictable correction of vertical osseous defects has however posed as a constant therapeutic challenge. The aim of our present study is to evaluate the relative efficacy of demineralized freeze-dried bone allograft (DFDBA) vs anorganic bovine bone xenograft (ABBX) in the treatment of human infrabony periodontal defects.

Materials and Methods:

15 patients with 30 bilaterally symmetrical defect sites in either of the arches, in the age group of 25-50 years were selected as part of split-mouth study design. Defect-A (right side) was grafted with DFDBA while Defect-B (left side) was grafted with ABBX. Various clinical and radiographic parameters viz. probing depth(PD), clinical attachment level(CAL) and linear bone fill were recorded preoperatively, 12- & 24-weeks postoperatively.

Results:

Both defect-A & defect-B sites exhibited a highly significant reduction in probing depth, and gain in clinical attachment level and linear bone fill at 12-weeks & at the end of 24-weeks. Comparative evaluation between the study groups revealed a statistically non-significant reduction in probing depth (P<0.1) and mean gain in linear bone fill (P<0.1). However, there was a statistically significant gain in clinical attachment level (P<0.05) in Defect-A (CD=0.356) as compared to Defect-B (CD=0.346).

Conclusions:

Within the limits of this study, both the materials viz. ABBX and DFDBA are beneficial for the treatment of periodontal infrabony defects. Both the materials were found to be equally effective in all respects except the gain in attachment level, which was found to be more with DFDBA. Long-term studies are suggested to evaluate further the relative efficacy of the two grafts.

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.

Platelet rich fibrin (Prf) and β-tricalcium phosphate with coronally advanced flap for the management of grade-II furcation defect

BACKGROUND

Multirooted teeth offer unique and challenging problems due to the furcation area, creates situations in which routine periodontal procedures are somewhat limited and special procedures are generally required.

CASE DETAIL

The present case was showing the management of grade II furcation defect by platelet rich fibrin (PRF) and β-Tricalcium phosphate with coronally advanced flap.

CONCLUSION

Platelet rich fibrin and β-Tricalcium phosphate with coronally advanced flap have been shown to be a promising and successful approach for the treatment of furcation defect. Its gaining clinical attachment significantly manages both the gingival recession and furcation involvement simultaneously.

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.

Anti-infective therapy with an Er:YAG laser: influence on peri-implant healing

In addition to conventional treatment modalities (mechanical and chemical), the use of lasers has been increasingly proposed for the treatment of periodontal and peri-implant infections (i.e., cleaning and detoxification of implant surfaces). Preliminary results from basic studies have pointed to the high potential of the Erbium-doped: Yttrium, Aluminum and Garnet (Er:YAG) laser. Furthermore, preliminary clinical data indicate that treatment with this kind of laser may positively influence peri-implant healing. The aim of this research update is to evaluate, based on the currently available evidence, the use of an Er:YAG laser for the treatment of peri-implant infections and to indicate its potential as a new treatment modality.

Use of lincomycin-impregnated demineralized freeze-dried bone allograft in the periodontal defect after third molar surgery

PURPOSE

The aim of the present study was to evaluate the periodontal regenerative capacity of demineralized freeze-dried bone allograft (DFDBA) alone or used with local lincomycin.

MATERIALS AND METHODS

In the present single-blind, randomized, controlled clinical trial, 20 subjects 26 years old or older, requiring extraction of bilateral third molars (M3s), were included. Each subject was randomly assigned to receive either DFDBA or DFDBA plus lincomycin therapy. Within the subjects, 1 M3 site was randomly selected to be the experimental site and the contralateral served as the control and was permitted to heal without intervention. The primary variables were changes in the probing depth (PD), clinical alveolar bone levels (ABLs), and radiographic alveolar bone density (ABD) on the distal aspect of second molar between baseline (immediately postoperatively) and 26 weeks postoperatively (T26). Appropriate sample sizes and descriptive, bivariate, and multivariate statistics were computed.

RESULTS

For both treatment and control sites, between T0 and T26, statistically significant improvements were seen in the ABLs and ABD (P < .05). Within-subject comparisons showed no significant differences in PD, ABL, or ABD between the treatment and control M3 sites at T0 or T26 (P > .05). Also, no significant differences were found in the PD, ABL, or ABD between the 2 treatment M3 sites at T26 (P > .05).

CONCLUSIONS

The results of the present study have revealed that the PD, ABL, and ABD improved after M3 removal in subjects 26 years old or older, irrespective of the treatment or control group. Reconstructive procedures (e.g., DFDBA with or without lincomycin therapy) did not offer predictable benefits compared with a no-treatment protocol in patients younger than 30 years old.

Clinical and radiographic evaluation of demineralized bone matrix (grafton) as a bone graft material in the treatment of human periodontal intraosseous defects

PURPOSE

The purpose of this clinical trial was to evaluate the efficacy of demineralized bone matrix (DBM) as a bone graft material in the treatment of human intrabony periodontal defects as compared with control defects treated by open flap debridement (OFD) alone.

MATERIALS AND METHODS

A controlled clinical trial was carried out for a period of 9 months in 11 patients (4 males and 7 females) with an age group of 25-50 years, contributing to a total of 30 defects. The selected defects were then randomly divided in to experimental sites (OFD + DBM) and control sites (OFD alone). Probing depth, clinical attachment levels and position of the gingival margin were recorded at baseline 3, 6 and 9 months post-operatively. Standardized radiographs (parallel technique) were also documented at these recall intervals.

RESULTS

On completion of 9 months, the mean percentage of probing depth reduction achieved in the experimental sites and control sites was 61.70%, 23.86% respectively. The mean percentage of clinical attachment level gain was 61.34% and 19.37% in the experimental and control sites respectively. In the experimental sites recession was observed to a lesser extent.

CONCLUSION

The use of DBM was more effective than OFD in improving clinical parameters and radiographic bone fill as shown in the present study. However, there is a need for further long term studies.

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.

BMP2 genetically engineered MSCs and EPCs promote vascularized bone regeneration in rat critical-sized calvarial bone defects

Current clinical therapies for critical-sized bone defects (CSBDs) remain far from ideal. Previous studies have demonstrated that engineering bone tissue using mesenchymal stem cells (MSCs) is feasible. However, this approach is not effective for CSBDs due to inadequate vascularization. In our previous study, we have developed an injectable and porous nano calcium sulfate/alginate (nCS/A) scaffold and demonstrated that nCS/A composition is biocompatible and has proper biodegradability for bone regeneration. Here, we hypothesized that the combination of an injectable and porous nCS/A with bone morphogenetic protein 2 (BMP2) gene-modified MSCs and endothelial progenitor cells (EPCs) could significantly enhance vascularized bone regeneration. Our results demonstrated that delivery of MSCs and EPCs with the injectable nCS/A scaffold did not affect cell viability. Moreover, co-culture of BMP2 gene-modified MSCs and EPCs dramatically increased osteoblast differentiation of MSCs and endothelial differentiation of EPCs in vitro. We further tested the multifunctional bone reconstruction system consisting of an injectable and porous nCS/A scaffold (mimicking the nano-calcium matrix of bone) and BMP2 genetically-engineered MSCs and EPCs in a rat critical-sized (8 mm) caviarial bone defect model. Our in vivo results showed that, compared to the groups of nCS/A, nCS/A+MSCs, nCS/A+MSCs+EPCs and nCS/A+BMP2 gene-modified MSCs, the combination of BMP2 gene -modified MSCs and EPCs in nCS/A dramatically increased the new bone and vascular formation. These results demonstrated that EPCs increase new vascular growth, and that BMP2 gene modification for MSCs and EPCs dramatically promotes bone regeneration. This system could ultimately enable clinicians to better reconstruct the craniofacial bone and avoid donor site morbidity for CSBDs.

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.

Comparative evaluation of autologous platelet-rich fibrin and platelet-rich plasma in the treatment of mandibular degree II furcation defects: a randomized controlled clinical trial

BACKGROUND

The treatment of molar furcation defects remains a considerable challenge in clinical practice. The identification of clinical measurements influential to treatment outcomes is critical to optimize the results of surgical periodontal therapy. The present study aimed to explore the clinical and radiographical effectiveness of autologous platelet-rich fibrin (PRF) and autologous platelet-rich plasma (PRP) in the treatment of mandibular degree II furcation defects in subjects with chronic periodontitis.

MATERIAL AND METHODS

Seventy-two mandibular degree II furcation defects were treated with either autologous PRF with open flap debridement (OFD; 24 defects) or autologous PRP with OFD (25), or OFD alone (23). Clinical and radiological parameters such as probing depth, relative vertical clinical attachment level and horizontal clinical attachment level along with gingival marginal level were recorded at baseline and 9 mo postoperatively.

RESULTS

All clinical and radiographic parameters showed statistically significant improvement at both the test sites (PRF with OFD and PRP with OFD) compared to those with OFD alone. Relative vertical clinical attachment level gain was also greater in PRF (2.87 ± 0.85 mm) and PRP (2.71 ± 1.04 mm) sites as compared to control site (1.37 ± 0.58 mm), and relative horizontal clinical attachment level gain was statistically significantly greater in both PRF and PRP than in the control group.

CONCLUSIONS

The use of autologous PRF or PRP were both effective in the treatment of furcation defects with uneventful healing of sites.