How to Select Replacement Grafts for Various Periodontal and Implant Indications

Simultaneous Implant and Guided Bone Regeneration Using Bovine-Derived Xenograft and Acellular Dermal Matrix in Aesthetic Zone

INTRODUCTION

Implant placement in the maxillary anterior area requires sufficient quantity and quality of both soft and hard tissue. In cases where soft and hard tissues are insufficient, additional regeneration using biomaterials is recommended. Treatment using bovine-derived xenograft and acellular dermal matrix (ADM) may increase bone volume and soft tissue thickness. Case and management: A 65-year-old woman sought help for discomfort and aesthetic issues with her denture, reporting missing teeth (11, 12, 13, 14, and 21) and bone volume shrinkage due to disuse atrophy. Intraoral examination revealed 1 mm gingival thickness. CBCT showed labio-palatal bone thickness of 6.0 mm, 5.8 mm, and 4.7 mm for teeth 21, 12 and 14, respectively. Implant planning and surgical guide fabrication were carried out before the surgery. Surgery included the placement of implants 3.3 mm in diameter and 12 mm in length, with the use of xenograft and ADM. Three months post-op, improvements in soft and hard tissues were observed, with a final prosthesis being a long-span implant-supported bridge.

CONCLUSIONS

Disuse alveolar atrophy causes soft and hard tissue deficiency. The use of xenograft and ADM show favourable results even on a geriatric patient.

Biological Effects of Orthodontic Tooth Movement on the Periodontium in Regenerated Bone Defects: A Scoping Review

The aim of this scoping review is to analyse the biological effects of the orthodontic tooth movement (OTM) in areas with bone defects that are undergoing regeneration using different types of regenerative materials and techniques. The electronic research was performed on four databases as follows: PubMed, Scopus, EMBASE, and Web of Science. Data were extracted according to publication information, study design, sample characteristics, parameters of OTM, biological repercussions on the periodontium complex, methods of analysis, and conclusions. A total of thirty studies were included in the final review. In twenty-two studies, the most widely adopted grafting materials were alloplastics. In most studies, the orthodontic force used was 10 or 100 g, and the timing of application ranged from immediate to 6 months after grafting surgery. Twenty-four studies showed an increase in osteogenesis; in five studies, the clinical attachment level (CAL) increased; in five others, the probing pocket depth (PPD) decreased; in sixteen studies, there was root resorption of a different magnitude. Though the effects of OTM on the periodontium in the grafted areas were positive, the outcomes should be interpreted with caution as future preclinical and clinical studies are needed to extrapolate more valid conclusions.

Optimized bone grafting

Bone grafting is routinely performed in periodontology and oral surgery to fill bone voids. While autogenous bone is considered the gold standard because of its regenerative properties, allografts and xenografts have more commonly been utilized owing to their availability as well as their differential regenerative/biomechanical properties. In particular, xenografts are sintered at high temperatures, which allows for their slower degradation and resorption rates and/or nonresorbable features. As a result, clinicians have combined xenografts with other classes of bone grafts (most notably allografts and autografts in various ratios) for procedures requiring better long-term stability, such as contour grafting, sinus elevation procedures, and vertical bone augmentations. This review addresses the regenerative properties of each class of bone grafts and then highlights the importance of understanding each of their biomechanical and regenerative properties for clinical applications, including extraction site management, contour augmentation, sinus grafting, and horizontal and vertical augmentation procedures. Thereafter, an introduction toward the novel production of nonresorbable bone allografts (NRBAs) via high-temperature sintering is presented. These NRBAs not only pose the advantage of being more biocompatible than xenografts owing to their origin (human vs. animal bone) but also display nonresorbable properties similar to those of xenografts. Thus, while packaging allografts with xenografts in premixtures specific to various clinical indications has never been permitted owing to cross-species contamination and FDA/CE requirements, the discovery and production of NRBAs allows premixing with standard allografts in various ratios without regulatory restrictions. Therefore, premixtures of allografts with NRBAs can be produced in various ratios for specific indications (e.g., a 1:1 ratio similar to an allograft/xenograft mixture for sinus grafting) without the need for purchasing separate classes of bone grafts. This optimized form of bone grafting could theoretically provide clinicians more precise ratios without the need to purchase separate bone grafts. This review highlights the future potential for simplified and optimized bone grafting in periodontology and implant dentistry.

Selection of bone graft material and proper timing of periodontal surgery for orthodontic patients: A systematic review

Introduction

Bone loss progression due to periodontitis can lead to pathologic tooth migration, ultimately compromising the overall structure and function of the oral cavity. In pathologic tooth migration, a periodontal-orthodontic interdisciplinary approach is necessary. The combination of a bone graft and orthodontic treatment has shown promising results for periodontal regeneration. The treatment sequence and selection of a bone graft define the success of the therapy.

Objective

This study aims to discuss the protocol of the interdisciplinary approach to regenerative periodontal surgery in cases of intrabony defects requiring orthodontic treatment.

Material & methods

Literature searches were conducted on four online databases (PubMed, Wiley, ScienceDirect, and Google Scholar). The keywords used were (intrabony defect OR vertical bone defect) AND (bone graft OR periodontal regeneration) AND (orthodontic). Out of 1656 studies that were retrieved initially, 14 full-text articles were checked for eligibility assessment. Finally, a total of seven studies met all of the requirements for inclusion in this study. This study includes two randomized controlled trials (RCTs), which are considered the highest level of evidence, however it is important to note that the overall evidence base is heterogeneous, inclusive of various study designs.

Discussion

Periodontal tissue damage must be addressed before considering orthodontic therapy, including cases with intrabony defects. On the basis of the seven studies, orthodontic therapy can be initiated as early as four weeks after surgery or as late as one year after periodontal surgery. Different types of bone graft materials, such as autografts, allografts, xenografts, and alloplasts, are used in the included studies. Three out of seven studies used autogenous graft combined with xenograft or enamel matrix derivative as the graft material as it is osteoconductive, osteogenic, and osteoinductive. Regular periodontal tissue maintenance therapy should be performed every 2-6 months, before, during, and after orthodontic treatment.

Conclusion

Making a proper diagnosis and treatment sequence is key to the success of a periodontal-orthodontic treatment. In addition, identifying the appropriate timing between periodontal surgery and orthodontic movement, selecting the most suitable bone graft material, and ensuring regular maintenance of periodontal tissue are important considerations.

Alloplastic Bone Substitutes for Periodontal and Bone Regeneration in Dentistry: Current Status and Prospects

Various bone graft products are commercially available worldwide. However, there is no clear consensus regarding the appropriate bone graft products in different clinical situations. This review is intended to summarize bone graft products, especially alloplastic bone substitutes that are available in multiple countries. It also provides dental clinicians with detailed and accurate information concerning these products. Furthermore, it discusses the prospects of alloplastic bone substitutes based on an analysis of the current market status, as well as a comparison of trends among countries. In this review, we focus on alloplastic bone substitutes approved in the United States, Japan, and Korea for use in periodontal and bone regeneration. According to the Food and Drug Administration database, 87 alloplastic bone graft products have been approved in the United States since 1996. According to the Pharmaceuticals and Medical Devices Agency database, 10 alloplastic bone graft products have been approved in Japan since 2004. According to the Ministry of Health and Welfare database, 36 alloplastic bone graft products have been approved in Korea since 1980. The approved products are mainly hydroxyapatite, β-tricalcium phosphate, and biphasic calcium phosphate. The formulations of the products differed among countries. The development of new alloplastic bone products has been remarkable. In the near future, alloplastic bone substitutes with safety and standardized quality may be the first choice instead of autologous bone; they may offer new osteoconductive and osteoinductive products with easier handling form and an adequate resorption rate, which can be used with growth factors and/or cell transplantation. Careful selection of alloplastic bone graft products is necessary to achieve predictable outcomes according to each clinical situation.

In Vitro Comparison of Macrophage Polarization and Osteoblast Differentiation Potentials between Granules and Block Forms of Deproteinized Bovine Bone Mineral

Deproteinized bovine bone mineral (DBBM) bone grafts are commonly utilized for guided bone regeneration (GBR) techniques in regenerative dentistry. It has been hypothesized that different forms (blocks versus particulates) might demonstrate the varying properties of cell behavior during the regenerative process. Therefore, the aim of the present study was to investigate DBBM granules and blocks for their effects on osteoblasts and macrophages (Mφs). DBBM granules and blocks were filled to the same size (φ6.4 mm in diameter × 2.0 mm in height) in cell culture wells and assessed for cell viability and cell differentiation of human osteoblast-like Saos-2 cells, and Mφs derived from human monocyte THP-1 cells. The two groups were first characterized by micro-CT analysis, which demonstrated that DBBM granules had a two-fold greater material volume and a four-fold larger surface area than the blocks. DBBM blocks showed superior viability for both osteoblasts and Mφs. Osteoblast experiments were then utilized to better characterize the influence of DBBM shapes/forms on osteoblast differentiation. Alkaline phosphatase (ALP) staining on the undecalcified frozen sections was observed throughout the DBBM granule surface, yet this staining was only observed on the upper portion of the DBBM blocks. Furthermore, DBBM blocks showed M1-Mφ polarization trends with higher IL-1 and IL-6 mRNA expression in Mφs, while the conditioned media from Mφs cultured on DBBM granules promoted osteoblast differentiation with higher mRNA levels of Runx 2, ALP and osteocalcin. In conclusion, the DBBM granules showed more regenerative effects, lower M1 marker expression, and higher osteoblast differentiation potential when compared with the blocks, which might be related to the larger material volume, higher surface area and greater ability for the cells to penetrate through the scaffold.

Interdisciplinary therapy for severe periodontitis with Angle Class II Division 1 malocclusion: A case report with 7-year follow-up

BACKGROUND AND OVERVIEW

Previous studies have suggested that occlusal discrepancy is a risk factor contributing to periodontal disease. Occlusal discrepancy could increase the risk of developing infrabony defects. The authors present a case of a patient with severe periodontitis who exhibited many infrabony defects in the molar region due to malocclusion-induced trauma. They report the 7-year treatment outcomes of the patient after periodontal regenerative and comprehensive orthodontic therapies for functional recovery with implant prosthodontics.

CASE DESCRIPTION

A 56-year-old woman sought treatment with the chief symptom of masticatory disturbance. In the molar region, excessive tooth mobility, deep periodontal pockets, and infrabony defects were observed. She had excessive overjet, resulting in collapse of anterior guidance. Malocclusion was considered to be an exacerbating factor of the infrabony defects. After initial periodontal therapy, the authors performed periodontal regenerative therapy in the mandibular molar regions. The authors carefully placed implants in a position in the maxillary molar region that would ensure an appropriate anterior dental relationship after orthodontic treatment. Comprehensive orthodontic treatment was subsequently performed, using implants as anchoring units. Definitive surgery was then performed on the mandibular molars before placing the final prosthesis. Favorable periodontal condition and stable occlusion have been maintained for the 7-year posttreatment period.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

Comprehensive and interdisciplinary treatment enables stable occlusion and establishment of periodontal and peri-implant tissues with high cleansability, even in patients with severe periodontitis and malocclusion. In this case, a favorable long-term treatment outcome can be expected.

New Perspectives in the Use of Biomaterials for Periodontal Regeneration

Periodontitis is a disease with a high prevalence among adults. If not treated, it can lead to loss of teeth. Periodontal therapy aims at maintaining patient’s teeth through infection control and correction of non-maintainable anatomies including—when possible—regeneration of lost periodontal tissues. The biological regenerative potential of the periodontium is high, and several biomaterials can be utilized to improve the outcome of periodontal therapy. Use of different natural and synthetic materials in the periodontal field has been studied for many years. The main materials used today in periodontology analyzed in this review are: Resorbable and non-resorbable barrier membranes; autogenous, allogeneic, xenogeneic, and alloplastic bone substitutes; biological agents, such as amelogenins; platelet-derived growth factor; bone morphogenic proteins; rh fibroblast growth factor 2; teriparatide hormone; platelet concentrates; and 3D scaffolds. With the development of new surgical techniques some concepts on periodontal regeneration that were strictly applied in the past seem to be not so critical today. This can have an impact on the materials that are needed when attempting to regenerate lost periodontal structures. This review aims at presenting a rationale behind the use of biomaterials in modern periodontal regeneration

Three-Dimensional Bone Substitutes for Oral and Maxillofacial Surgery: Biological and Structural Characterization

Background: Bone substitutes, either from human (autografts and allografts) or animal (xenografts) sources, suffer from inherent drawbacks including limited availability or potential infectivity to name a few. In the last decade, synthetic biomaterials have emerged as a valid alternative for biomedical applications in the field of orthopedic and maxillofacial surgery. In particular, phosphate-based bone substitution materials have exhibited a high biocompatibility due to their chemical similitude with natural hydroxyapatite. Besides the nature of the biomaterial, its porous and interconnected architecture is essential for a correct osseointegration. This performance could be predicted with an extensive characterization of the biomaterial in vitro. Methods: In this study, we compared the biological, chemical, and structural features of four different commercially available bone substitutes derived from an animal or a synthetic source. To this end, µ-CT and SEM were used to describe the biomaterials structure. Both FTIR and EDS analyses were carried out to provide a chemical characterization. The results obtained by these techniques were correlated with cell adhesion and proliferation of the osteosarcoma MG-63 human cell line cultured in vitro. Results: The findings reported in this paper indicate a significant influence of both the nature and the structure of the biomaterials in cell adhesion and proliferation, which ultimately could affect the clinical performance of the biomaterials. Conclusions: The four commercially available bone substitutes investigated in this work significantly differed in terms of structural features, which ultimately influenced in vitro cell proliferation and may so affect the clinical performance of the biomaterials.

Bone regeneration using a porcine bone substitute collagen composite in vitro and in vivo

The biocharacteristics of xenogeneic grafts make them a possible substitute for autogenous bone grafts in dental bone graft procedures. This study aimed to develop a novel porcine graft with collagen capable of generating new bone in bone defects via osteoconduction over 8 weeks of healing and to compare it with a porcine graft. The porcine collagen graft was made to undergo a cell viability test (MTT) and alkaline phosphatase assay (ALP). The surgical procedure was performed in 20 male adult New Zealand white rabbits. Four calvarial critical-size defects of 6 mm in diameter were prepared in each rabbit. The upper left defect was filled with a porcine graft of 500–1000 μm, the upper right with a porcine collagen graft, the lower left with hydroxyapatite/beta-tricalcium phosphate and the lower right served as the control without any filling material. The rabbits were divided and sacrificed at 2, 4, 6 and 8 weeks after surgery. Histological and micro-CT scan results showed that the performance of the porcine collagen graft is superior for regenerating new bone. Porcine collagen graft showed cell viability and osteoblast-like cell differentiation in vitro. The results indicate that porcine collagen graft is a potential bone substitute for clinical application.

Carbon Nanotubes

One of the main goals of bone tissue engineering is to identify and develop new biomaterials and scaffolds for structural support and controlled cell growth, which allow for formation or replacement of bone tissue. Recently, carbon nanotubes (CNT) have emerged as a potential candidate for bone tissue engineering. CNT present remarkable mechanical, thermal, and electrical properties with easy functionalization capability and biocompatibility. In oral regenerative medicine, bone reconstruction is an essential requirement for functional rehabilitation of the stomatognathic system. Autologous bone still represents the gold standard graft material for bone reconstruction. However, the small amounts of bone available in donor regions, together with the high costs of surgeries, are critical aspects that hinder the selection of this procedure. Thus, CNT alone or combined with biopolymers have promise to be used as novel potential biomaterials for the restoration of bone defects. Indeed, recent evidence demonstrates CNT to be a feasible material that can increase the formation of bone in tooth sockets of rats. The purpose of this review is to summarize the recent developments in bone repair/regeneration with CNT or CNT-based composites. We further provide an overview of bone tissue engineering and current applications of biomaterials, especially of CNT, to enhance bone regeneration.