A comparison of bovine bone and hydroxyapatite scaffolds during initial bone regeneration: an in vitro evaluation

Bone Grafts in Dental Medicine: An Overview of Autografts, Allografts and Synthetic Materials

This review provides an overview of various materials used in dentistry and oral and maxillofacial surgeries to replace or repair bone defects. The choice of material depends on factors such as tissue viability, size, shape, and defect volume. While small bone defects can regenerate naturally, extensive defects or loss or pathological fractures require surgical intervention and the use of substitute bones. Autologous bone, taken from the patient's own body, is the gold standard for bone grafting but has drawbacks such as uncertain prognosis, surgery at the donor site, and limited availability. Other alternatives for medium and small-sized defects include allografts (from human donors), xenografts (from animals), and synthetic materials with osteoconductive properties. Allografts are carefully selected and processed human bone materials, while xenografts are derived from animals and possess similar chemical composition to human bone. Synthetic materials such as ceramics and bioactive glasses are used for small defects but may lack osteoinductivity and moldability. Calcium-phosphate-based ceramics, particularly hydroxyapatite, are extensively studied and commonly used due to their compositional similarity to natural bone. Additional components, such as growth factors, autogenous bone, and therapeutic elements, can be incorporated into synthetic or xenogeneic scaffolds to enhance their osteogenic properties. This review aims to provide a comprehensive analysis of grafting materials in dentistry, discussing their properties, advantages, and disadvantages. It also highlights the challenges of analyzing in vivo and clinical studies to select the most suitable option for specific situations.

Implants Survival Rate in Regenerated Sites with Innovative Graft Biomaterials: 1 Year Follow-Up

In thirteen different dental clinics in Singapore, Spain, Czech Republic and Italy, 504 patients were selected, and 483 dental implants were placed in maxillary sites after alveolar socket preservation (ASP) procedures with an autologous demineralized tooth extracted as graft material from an innovative Tooth Transformer device was obtained. All procedures used were reported in n°638 Ethical Committee surgical protocol of University of Chieti and approved. After 4 months, at dental implant placing, bone biopsies were performed to evaluate the histologic outcomes, and 12 months after implant loading, global implant survival rate, failure percentage and peri-implant bone loss were detected. After ASP, only 27 post-operative complications were observed and after 4 months, bone biopsy histomorphometric analysis showed a high percentage of bone volume (BV) 43.58 (±12.09), and vital new bone (NB) 32.38 (±17.15) with an absence of inflammation or necrosis areas. Twelve months after loading, only 10 dental implants failed (2.3%), with a 98.2% overall implant survival rate, nine cases showed mucositis (1.8%) and eight showed peri-implantitis (1.6%). At mesial sites, 0.43 mm (±0.83) of bone loss around the implants was detected and 0.23 mm (±0.38) at the distal sites with an average value of 0.37 mm (±0.68) (p > 0.568). Several studies with a longer follow-up will be necessary to confirm the preliminary data observed. However, clinical results seem to suggest that the post-extraction socket preservation procedure using innovative demineralized autologous tooth-derived biomaterial may be a predictable procedure to produce new vital bone able to support dental implant rehabilitation of maxilla edentulous sites.

Skeletal microenvironment system utilising bovine bone scaffold co-cultured with human osteoblasts and osteoclast-like cells

A three-dimensional ex vivo bone cell culture system mimicking the skeletal system is useful for bone tissue engineering and as drug discovery platforms. The present study aimed to establish a three-dimensional skeletal culture system using native bovine bone scaffolds and human bone cells. Bovine bone scaffolds were cultured with human foetal osteoblasts 1.19 and human peripheral blood mononuclear cells for 21 days under standard culture conditions. The following groups were established: Decalcified unseeded bone scaffold (DUBS) as baseline control, decalcified seeded bone scaffold (DSBS) to mimic osteoporosis condition and undecalcified seeded bone scaffold to mimic normal condition. The scaffold's porosity and cell attachment on the scaffolds were determined using scanning electron microscopy. Histological evaluation was used to examine changes in trabecular bone structure. Dual-energy X-ray absorptiometry analysis was performed to determine the bone mineral density (BMD) and bone mineral content (BMC) of the scaffolds. A compression test was performed to examine the total biomechanical strength of the scaffolds. The trabecular thickness and number increased, while the trabecular separationwas reduced slightly in DSBS than in DUBS (P>0.05). The BMD and BMC increased significantly (P<0.05), while the compressive strength only increased slightly in DSBS than in DUBS (P>0.05). In conclusion, the ex vivo skeletal microenvironment comprising native bovine bone scaffolds seeded with bone cells is structurally, functionally and mechanically comparable with natural bone. This system may be used as a platform to understand bone physiology and screen for potential drug candidates.

Alveolar Socket Preservation with Different Autologous Graft Materials: Preliminary Results of a Multicenter Pilot Study in Human

BACKGROUND

The histological and histomorphometrical results were evaluated between vital whole and non-vital endodontically treated teeth used as autologous grafts in post-extractive socket preservation procedures.

METHODS

Twenty-eight patients (average age 51.79 ± 5.97 years) with post-extractive defects were enrolled in five dentistry centers. All patients were divided into two groups: with whole teeth (Group 1) and teeth with endodontical root canal therapy (Group 2). The extracted teeth were processed with the Tooth Transformer device to obtain a demineralized and granulated graft material used with a resorbable collagen membrane for socket preservation. After four months, 32 bone biopsies were obtained for histological, histomorphometric, and statistical analysis.

RESULTS

During the bone healing period, no infection signs were observed. Nineteen biopsies in group 1 and 13 biopsies in group 2 were detected. The histological analysis showed neither inflammatory nor infective reaction in both groups. Autologous grafts surrounded by new bone were observed in all samples and, at high magnification, partially resorbed dentin and enamel structures were detected. No gutta-percha or cement was identified. Small non-statistically significant differences between the groups, in total bone volume (BV), autologous graft residual, and vital bone percentage were detected.

CONCLUSIONS

The study showed that the TT Transformer grafts were capable of producing new vital bone in socket preservation procedures. The histomorphometric results showed no statistical differences comparing whole and endodontically treated teeth in bone regeneration. Further studies will be carried out in order to understand the advantages of the autologous graft materials obtained from the tooth compared with the current biomaterials in bone regeneration treatments.

Efficacy of a new coating of implant-abutment connections in reducing bacterial loading: an in vitro study

BACKGROUND

Titanium is the gold standard for dental implants, since it has demonstrated excellent biocompatibility and osseointegration properties. The rate of osseointegration is however affected by the surface morphology and peri-implant infections may affect fixture and the long-term osseointegration outcome. Thus chemical composition of a coating at the implant-abutment junction (IAJ) surface is expected to play a key role in preventing bacterial infection.

PURPOSE

In the present study a new antimicrobial polysiloxane coating functionalized with chlorexidine digluconate (PXT) has been tested in an in vitro model.

MATERIALS AND METHODS

Twenty implants were coated in the internal chamber with PXT and twenty were used as controls.

RESULTS AND CONCLUSIONS

Ten of the coated implants, preliminarily tested against Gram positive and negative bacteria and fungi, showed a complete inactivation of the microbial species after a 15 min contact. On the remaining ten treated implants a series of microbiological tests and PCR analysis, after contamination of the implant external medium, in which the implant have been immersed, with genetic modified Tannerella forsythia (TF) and Porphyromonas Gingivalis (PG), leads to the conclusion that the coating is capable of inactivating the microbial species penetrating the internal of the implant through the implant abutment junction.

Genetic susceptibility and periodontal disease: a retrospective study on a large italian sample

BACKGROUND

Periodontal disease (PD) is a multifactorial illness in which environment and host interact. The genetic component plays a key role in the onset of PD. In fact the genetic compound can modulate the inflammation of the mucous membranes and the loss of alveolar bone. The genetics of PD is not well understood. Previous studies suggest a strong association between PD occurrence and individual genetic profile. The role of genetic susceptibility could impact on the clinical manifestations of PD, and consequently on prevention and therapy.

MATERIALS AND METHODS

Genetic polymorphisms of VRD, IL6 and IL10 were investigated in Italian adults affected by PD. 571 cases classified according the criteria of the American Academy of Periodontology were included. All patients were Italian coming from three areas according to italian institute of statistics (ISTAT) (www.istat.it/it/archivio/regioni). The sample comprised 379 patients from North (66%), 152 from Central (26%) and 40 of South (8%).

RESULTS

No significant differences were found among allele distribution.

CONCLUSION

Chronic PD is a complex disease caused by a combination of genetic susceptibility, patients habits (oral hygiene, smoking, alcohol consumption) and oral pathogens. In our report no differences were detected among three Italian regions in allele distribution.

Prevalence of periodontal pathogens among italian patients with chronic periodontitis: a retrospective study on 2992 patients

PURPOSE

The aim of the present study was to evaluate the prevalence of some periodontal pathogens in Italian adults with chronic periodontitis.

MATERIALS AND METHODS

The sample consisted of 2992 patients with a clinical diagnosis of chronic periodontitis, based on the criteria of the American Academy of Periodontology, sampled in the period 2013-2016: 2108 patients were from Northern, 690 from Central and 194 from Southern Italy. Porphyromonas gengivalis, Treponema denticola, and Tannerella forsythia were investigated in all patients of the present study, while Campylobacter rectus, Fusobacterium nucleatum and Aggregatibacter actinomycetemcomitans only in 2514 (84%) patients. Subgingival plaque samples of the four sites of greatest probing depth in each patient were used to obtain subgingival microbiota and then processed by quantitative polymerase chain reaction.

RESULTS

Periodontal pathogens had the following presence respect to all amount of patients: Aggregatibacter actinomycetemcomitans 16.1%, Campylobacter rectus 73.4%, Fusobacterium nucleatum 93.8%, Porphyromonas gengivalis 65.5%, Treponema denticola 66.4%, and Tannerella forsythia 72.7%. There are no significant statistical differences among geographic areas both for the total bacterial and the single species except for T. Denticola and C. Rectus, which prevalence was significantly higher in Southern Italy (P value <.05). The other investigated species were equally distributed among different regions. A. actinomycetemcomitans was the rarer species detected in this study, while F. nucleatum was the commonest. No differences among areas where observed as regard of the mean bacterial load except for F. Nucleatum whose prevalence in Northern Italy was lower then both in Central and Southern Italy (P value <.05).

CONCLUSIONS

The results of our study didn't show different geographic distribution of periodontal pathogens among Italian population of the three areas investigated. The homogeneity of the results could be related to genetic and environmental factors.

Application of tissue-engineered bone grafts for alveolar cleft osteoplasty in a rodent model

OBJECTIVES

The clinical standard for alveolar cleft osteoplasty is augmentation with autologous bone being available in limited amounts and might be associated with donor site morbidity. The aim of the present study was the creation of tissue-engineered bone grafts and their in vivo evaluation regarding their potential to promote osteogenesis in an alveolar cleft model.

MATERIALS AND METHODS

Artificial bone defects with a diameter of 3.3 mm were created surgically in the palate of 84 adult Lewis rats. Four experimental groups (n = 21) were examined: bovine hydroxyl apatite/collagen (bHA) without cells, bHA with undifferentiated mesenchymal stromal cells (MSC), bHA with osteogenically differentiated MSC. In a control group, the defect remained empty. After 6, 9 and 12 weeks, the remaining defect volume was assessed by cone beam computed tomography. Histologically, the remaining defect width and percentage of bone formation was quantified.

RESULTS

After 12 weeks, the remaining defect width was 60.1% for bHA, 74.7% for bHA with undifferentiated MSC and 81.8% for bHA with osteogenically differentiated MSC. For the control group, the remaining defect width measured 46.2% which was a statistically significant difference (p < 0.001).

CONCLUSIONS

The study design was suitable to evaluate tissue-engineered bone grafts prior to a clinical application. In this experimental set-up with the described maxillary defect, no promoting influence on bone formation of bone grafts containing bHA could be confirmed.

CLINICAL RELEVANCE

The creation of a sufficient tissue-engineered bone graft for alveolar cleft osteoplasty could preserve patients from donor site morbidity.

Applications of biomaterials for bone augmentation of jaws: clinical outcomes and in vitro studies

Partially or totally edentulous jaws frequently undergoes from moderate to severe bone atrophy with problems of prosthetic rehabilitation. The inability to make a prosthetic rehabilitation on implants may led to the use of a partial or total removable denture with difficulties in eating and speech, ulcerations of the oral mucosa and loss of facial vertical dimension. These problems may be solved performing bone augmentation procedures. Bone grafts and distraction osteogenesis brought implant dentistry from an experimental practice to become a consolidate dental procedure. Bone grafts, in particular, are currently a valuable treatment modality for the prosthetic rehabilitation. Numerous biomaterials have been developed for the rehabilitation of partially or totally edentulous jaws with fixed or removable dentures. The aim of this paper is to describe biomaterials for bone augmentation. Biomaterials are gradually resorbed by the osteoclasts and replaced by new bone formed through osteoblastic activity. Many biomaterials have been studied, but the most common are as follows: Allogro®, Algipore®, Osteobiol®, Peptide-15, Engipore®, Medpore®, Osteoplant®, Calcium sulfate, Perioglass®, Bio-Oss®, Calcium phosphate.

Basic concepts regarding fracture healing and the current options and future directions in managing bone fractures

Fracture healing is a complex physiological process, which involves a well-orchestrated series of biological events. Repair of large bone defects resulting from trauma, tumours, osteitis, delayed unions, non-unions, osteotomies, arthrodesis and multifragmentary fractures is a current challenge of surgeons and investigators. Different therapeutic modalities have been developed to enhance the healing response and fill the bone defects. Different types of growth factors, stem cells, natural grafts (autografts, allografts or xenografts) and biologic- and synthetic-based tissue-engineered scaffolds are some of the examples. Nevertheless, these organic and synthetic materials and therapeutic agents have some significant limitations, and there are still no well-approved treatment modalities to meet all the expected requirements. Bone tissue engineering is a newer option than the traditional grafts and may overcome many limitations of the bone graft. To select an appropriate treatment strategy in achieving a successful and secure healing, more information concerning injuries of bones, their healing process and knowledge of the factors involved are required. The main goals of this work are to present different treatment modalities of the fractured bones and to explain how fractures normally heal and what factors interfere with fracture healing. This study provides an overview of the processes of fracture healing and discusses the current therapeutic strategies that have been claimed to be effective in accelerating fracture healing.