Computer-aided design/computer-aided manufacturing of hydroxyapatite scaffolds for bone reconstruction in jawbone atrophy: a systematic review and case report

Application of CAD-CAM Technologies for Maxillofacial Bone Regeneration: A Narrative Review of the Clinical Studies

The application of regenerative methods in treating maxillofacial defects can be categorized as functional bone regeneration in which scaffolds without protection are used and in-situ bone regeneration in which a protected healing space is created to induce bone formation. It has been shown that functional bone regeneration can reduce surgical time and obviate the necessity of autogenous bone grafting. However, studies mainly focused on applying this method to reconstruct minor bone effects, and more investigation concerning the large defects is required. In terms of in situ maxillofacial bone regeneration with the help of CAD-CAM technologies, the present data have suggested feasible mesh rigidity, perseverance of the underlying space, and apt augmentative results with CAD-CAM-based individualized Ti meshes. However, complications, including dehiscence and mesh exposure, coupled with consequent graft loss, infection and impeded regenerative rates have also been reported.

Application of biodegradable Patient-specific scaffolds for maxillofacial bone regeneration: a scoping review of clinical studies

This study aimed to systematically review clinical studies in which biodegradable patient-specific scaffolds were used for bone regeneration. Studies in which biodegradable scaffolds were fabricated through computer-assisted design and computer-assisted manufacturing (CAD-CAM) procedures were included. Those that applied non-biodegradable materials or used biodegradable materials in a condensable powder or block form were excluded. Among a total of 26 included studies, 11 used customised allogeneic bone blocks, five used polycaprolactone (PCL)-containing scaffolds, four used hydroxyapatite (HA) scaffolds, and four biphasic calcium phosphate (BCP). The majority of the studies applied scaffolds for minor intraoral defects. All the large defects were reconstructed with polymer-containing scaffolds. Results of the included studies showed partial to complete filling of the defect following the application of biodegradable scaffolds. However, limited graft exposure was reported when using PCL, BCP, and HA scaffolds. Tissue engineering can be considered a potential method for the treatment of maxillofacial bone defects. However, more evidence is required, especially for the application of biodegradable scaffolds in large defects.

Alveolar ridge augmentation with 3D-printed synthetic bone blocks: A clinical case series

This report documents the clinical and histological outcome of 3D-printed calcium phosphate blocks placed in two-stage procedures to successfully rehabilitate atrophic alveolar ridges. This approach yielded a functionally favorable result. Histological evaluations were performed after healing periods of 6 months and showed ongoing bone regeneration and sprouting capillaries.

Investigating the accuracy of mandibulectomy and reconstructive surgery using 3D customized implants and surgical guides in a rabbit model

BACKGROUND

This study aimed to analyze the accuracy of the output of three-dimensional (3D) customized surgical guides and titanium implants in a rabbit model, and of mandibulectomy, reconstructive surgery, and surgical outcome; additionally, the correlation between surgical accuracy and surgical outcomes, including the differences in surgical outcome according to surgical accuracy, was analyzed.

RESULTS

The output of implants was accurately implemented within the error range (- 0.03-0.03 mm), and the surgical accuracy varied depending on the measured area (range - 0.4-1.1 mm). Regarding surgical outcomes, angle between the mandibular lower borders showed the most sensitive results and distance between the lingual cusps of the first molars represented the most accurate outcomes. A significant correlation was noted between surgical accuracy in the anteroposterior length of the upper borders pre- and postoperatively and the angle between the mandibular lower borders (regression coefficient = 0.491, p = 0.028). In the group wherein surgery was performed more accurately, the angle between the mandibular lower borders was reproduced more accurately (p = 0.021). A selective laser melting machine accurately printed the implants as designed. Considering the positive correlation among surgical accuracy in the mandibular upper borders, angle between the mandibular lower borders, and more accurately reproduced angle between the mandibular lower borders, the angle between the mandibular lower borders is considered a good indicator for evaluating the outcomes of reconstructive surgery.

CONCLUSION

To reduce errors in surgical outcomes, it is necessary to devise a positioner for the surgical guide and design a 3D surgical guide to constantly maintain the direction of bone resection. A fixed area considering the concept of three-point fixation should be selected for stable positioning of the implant; in some cases, bilateral cortical bone fixation should be considered. The angle between the mandibular lower borders is a sensitive indicator for evaluating the outcomes of reconstructive surgery.

Total mandible and bilateral TMJ reconstruction combining a customized jaw implant with a free fibular flap: a case report and literature review

BACKGROUND

The need for whole mandibular bone reconstruction and bilateral joint replacement is fortunately rare, but it is an extremely challenging topic in maxillofacial surgery, due to its functional implications. CAD-CAM techniques development has opened new broad horizons in the surgical planning of complex maxillofacial reconstructions, in terms of accuracy, predictability, and functional cosmetic results. The review of the literature has revealed a small number of scientific reports on total mandibulectomy including the condyles, with only eleven cases from 1980. Most of the works describe reconstructions secondary to dysplastic or inflammatory diseases affecting the lower jaw. The aim of this work, reporting a rare case of massive fibrous dysplasia of the whole mandible, is to share our experience in the management of extended mandibular and bilateral joint reconstruction, using porous titanium patient-specific implants.

CASE PRESENTATION

The authors present a 20-year-old male patient suffering from massive bone fibrous dysplasia of the mandible. The mandibular body and both the rami and the condylar processes had been involved, causing severe functional impairment, tooth loss, and facial deformation. The young patient, after repeated ineffective conservative surgical treatments, has required a biarticular mandibular replacement. Using virtual surgical planning (VSP) software, the authors, in collaboration with medical engineers, have created a custom-made original titanium porous mandibular implant, suspended from a bilateral artificial temporomandibular joint. The mandibular titanium implant body has been specifically designed to support soft tissues and to fix, in the alveolar region, a free fibular bone graft, for delayed dental implant prosthetic rehabilitation.

CONCLUSION

The surgical and technical details, as well as the new trends in mandibular reconstructions using porous titanium implants, are reported, and discussed, reviewing literature reports on this topic. Satisfactory functional and cosmetic restorative results have been obtained, and no major complications have occurred. The patient, currently in the 18^th month clinical and radiological follow-up, has recently completed the functional restoration program by an implant-supported full-arch dental prosthesis.

Custom-made computer-aided-design/ computer-assisted-manufacturing (CAD/CAM) synthetic bone grafts for alveolar ridge augmentation: A retrospective clinical study with 3 years of follow-up

PURPOSE

To report on the results obtained with computer-aided-design/ computer-assisted-manufacturing (CAD/CAM) custom-made synthetic hydroxyapatite/beta-tricalcium-phosphate (HA/beta-TCP) bone grafts in alveolar ridge augmentation for dental implant placement.

METHODS

The procedure included: (1) cone-beam computed tomography (CBCT) of the bone defect; (2) virtual design of the custom-made onlay bone grafts; (3) milling of grafts from a pre-formed block of synthetic HA/beta-TCP; and (4) bone reconstructive surgery. Implants were placed 8 months later. The patients were followed for 3 years. The study outcomes were: (1) intra- and immediate post-operative complications; (2) 8-month vertical and horizontal bone gain; (3) implant survival; (4) implant-crown success; and (5) peri-implant marginal bone loss (MBL).

RESULTS

Twenty-six patients underwent ridge augmentation with custom-made CAD/CAM HA/beta-TCP onlay grafts. Eight months later, these patients were rehabilitated with dental implants. During surgery, 25/26 (96.1%) of the grafts adapted well to the bone defect. Immediate post-operative complications were pain and swelling (2/26 patients: 7.6%), and bone graft exposure (3/26: 11.5%); one exposure led to infection, removal of the graft, and failure of the procedure. Excellent integration of the other grafts was observed 8 months after the regenerative procedure, with mean vertical and horizontal bone gains of 2.10 mm (± 0.35) and 2.96 mm (± 0.45), respectively. Twenty-five implants were placed and restored with single crowns. Three years later, all implants were in function. The 3-year implant crown success rate and peri-implant MBL were 92.0% and 0.7 mm (±0.19), respectively.

CONCLUSIONS

With custom-made CAD/CAM synthetic HA/beta-TCP onlay grafts reconstruction of small vertical and/or horizontal defects of the alveolar ridge was obtained; this enabled implant placement, with high implant-crown success rate after 3 years. Further studies are needed to validate this technique.

STATEMENT OF CLINICAL RELEVANCE

Custom-made CAD/CAM synthetic HA/beta-TCP onlay grafts may represent an option for regeneration of small bone defects prior to implant placement.

The use of 3D ceramic block graft compared with autogenous block graft for rehabilitation of the atrophic maxilla: a randomized controlled clinical trial

Background

Dental implant placement may require a bone graft for vertical and horizontal alveolar ridge augmentation. Due to its osteoconduction, osteoinductive, and osteogenesis, autogenous bone graft characteristics are considered the standard gold treatment. However, autografts can promote postoperative morbidity and implicate difficulties concerning the graft adaptation to the recipient's bone since it can eventually avoid gaps. To overcome these issues, this trial will compare the performance of Plenum® Oss 3Dβ fit, an alloplastic graft, and a 3D-printed patient-specific graft based on β-tricalcium phosphate to the autograft procedure.

Methods

This is a split-mouth randomized clinical study designed to evaluate the performance of personalized (patient-specific) bioceramic bone grafts (Plenum® Oss 3Dβ fit) for bone augmentation of the atrophic anterior maxilla in comparison to the autogenous bone graft. We hypothesize that the gain and maintenance of the grafted area volume and the quality of the newly formed bone tissue after eight months postoperative with the synthetic patient-specific graft will be superior to the autogenous bone graft. To assess the quantity and the quality of bone neoformation, volumetric and histological analyses will be performed.

Discussion

The fabrication of medical devices by additive manufacturing presents advantages over conventional manufacturing processes, mostly related to the precision of geometry and anatomy. Additionally, the osteoconductive proprieties of β-tricalcium phosphate enable this synthetic bone substitute as an alternative solution over autogenous graft for bone defect reconstruction. Thus, patient-specific bone grafts can potentially improve patient satisfaction, reducing the need for autogenous bone grafts, consequently avoiding implications related to this type of treatment, such as patient morbidity.

Trial registration

This study is registered in REBEC (Registro Brasileiro de Ensaios Clínicos): RBR-76wmm3q; UTN: U1111-1272-7773. Registration date: 14 September 2021.

Our problems and observations in 3D facial implant planning

BACKGROUND

Three-dimensional renderings of two-dimensional computed tomography data have allowed for more precise analysis in the craniofacial field. Design, engineering, architecture, and other industries have paved the way for the manipulation and printing of three-dimensional objects. The usual planning is only carried out based on the bony structures, often without taking into consideration the presence of soft tissues and soft structures. During our practice, we have found ourselves facing the challenge posed by these structures; the aim of this article is to discuss our experience in designing implants presenting our tips and tricks for a better planning leading to an easy and reliable positioning.

CASE PRESENTATION

We have retrieved all patients in 5 years among those who underwent computer-aided design/computer-aided manufacturing implant placement in the last 5 years in order to review the eventual problems and the solutions found. A total number of 25 patients were retrieved and, among them, 10 patients were selected, in which planning inaccuracy caused difficulties during implant placement and which then led to induced changes during the planning of similar cases or in which the problems were noted before or during the planning which led to changes in the plan to address those problems. Six of the selected cases were polyetheretherketone facial implants for the correction of residual deformities in malformed or deformed patients. One case was a delayed orbital reconstruction with a titanium implant. Two cases were titanium functional and anatomical reconstruction of the mandible in patients with failed post-oncological reconstructions. There was 1 case with a mandibular ramus complex and hard-to-treat fracture.

CONCLUSIONS

The planning of the implant mostly relies on hard tissue three-dimensional reconstruction, but it should not be limited at what is immediately evident. A surgeon's clinical experience should always guide the process, with knowledge of the patient's anatomy and evaluation of the quality and of the soft tissue response being taken into consideration. The implant should always be tailored not only based on the bone defect and evaluations but also using the patient's previewed and actual anatomy, evaluating eventual interferences and pitfalls.

Multidisciplinary approach to Gorlin-Goltz syndrome: from diagnosis to surgical treatment of jawbones

BACKGROUND

Gorlin syndrome, also known as Gorlin-Goltz syndrome (GGS) or basal cell nevus syndrome (BCNS) or nevoid basal cell carcinoma syndrome (NBCCS), is an autosomal dominant familial cancer syndrome. It is characterized by the presence of numerous basal cell carcinomas (BCCs), along with skeletal, ophthalmic, and neurological abnormalities. It is essential to anticipate the diagnosis by identifying the pathology through the available diagnostic tests, clinical signs, and radiological manifestations, setting up an adequate treatment plan.

MAIN BODY

In the first part, we searched recent databases including MEDLINE (PubMed), Embase, and the Cochrane Library by analyzing the etiopathogenesis of the disease, identifying the genetic alterations underlying them. Subsequently, we defined what are, to date, the major and minor clinical diagnostic criteria, the possible genetic tests to be performed, and the pathologies with which to perform differential diagnosis. The radiological investigations were reviewed based on the most recent literature, and in the second part, we performed a review regarding the existing jawbone protocols, treating simple enucleation, enucleation with bone curettage in association or not with topical use of cytotoxic chemicals, and "en bloc" resection followed by possible bone reconstruction, marsupialization, decompression, and cryotherapy.

CONCLUSION

To promote the most efficient and accurate management of GGS, this article summarizes the clinical features of the disease, pathogenesis, diagnostic criteria, differential diagnosis, and surgical protocols. To arrive at an early diagnosis of the syndrome, it would be advisable to perform radiographic and clinical examinations from the young age of the patient. The management of the patient with GGS requires a multidisciplinary approach ensuring an adequate quality of life and effective treatment of symptoms.

Bone Regeneration of a 3D-Printed Alloplastic and Particulate Xenogenic Graft with rhBMP-2

This study aimed to evaluate the bone regeneration capacity of a customized alloplastic material and xenograft with recombinant human bone morphogenetic protein-2 (rhBMP-2). We prepared hydroxyapatite (HA)/tricalcium phosphate (TCP) pure ceramic bone blocks made using a 3D printing system and added rhBMP-2 to both materials. In eight beagle dogs, a total of 32 defects were created on the lower jaws. The defective sites of the negative control group were left untreated (N group; 8 defects), and those in the positive control group were filled with particle-type Bio-Oss (P group; 12 defects). The defect sites in the experimental group were filled with 3D-printed synthetic bone blocks (3D group; 12 defects). Radiographic and histological evaluations were performed after healing periods of 6 and 12 weeks and showed no significant difference in new bone formation and total bone between the P and 3D groups. The 3D-printed custom HA/TCP graft with rhBMP-2 showed bone regeneration effects similar to that of particulate Bio-Oss with rhBMP-2. Through further study and development, the application of 3D-printed customized alloplastic grafts will be extended to various fields of bone regeneration.

Hydroxyapatite Nanoparticles as Injectable Bone Substitute Material in a Vertical Bone Augmentation Model

AIM

The aim of this in vivo study was to evaluate the utility of bone graft gel containing hydroxyapatite nanoparticles in promoting bone regeneration in a mouse model of vertical bone augmentation.

MATERIALS AND METHODS

Gel implants with high and low viscosity were compared for their bone regenerating ability. Bone formation at 12 weeks and material reactions were observed radiographically and histologically.

RESULTS

Radiological analysis showed that most bone augmentation area in the graft material occurred in the fourth week after surgery regardless of the viscosity of the gel, and then gradually decreased. The volume of bone augmentation area was greater in the high-viscosity implant group than in the low-viscosity implant group at all time points, the difference was statistically significant at 8 and 12 weeks. Histological evaluation indicated that the new bone area was significantly smaller in the high-viscosity implant group.

CONCLUSION

Gelatinous graft materials containing hydroxyapatite nanoparticles were confirmed to be useful in vertical bone augmentation.

3D-Printed Ceramic Bone Scaffolds with Variable Pore Architectures

This study evaluated the mechanical properties and bone regeneration ability of 3D-printed pure hydroxyapatite (HA)/tricalcium phosphate (TCP) pure ceramic scaffolds with variable pore architectures. A digital light processing (DLP) 3D printer was used to construct block-type scaffolds containing only HA and TCP after the polymer binder was completely removed by heat treatment. The compressive strength and porosity of the blocks with various structures were measured; scaffolds with different pore sizes were implanted in rabbit calvarial models. The animals were observed for eight weeks, and six animals were euthanized in the fourth and eighth weeks. Then, the specimens were evaluated using radiological and histological analyses. Larger scaffold pore sizes resulted in enhanced bone formation after four weeks (p < 0.05). However, in the eighth week, a correlation between pore size and bone formation was not observed (p > 0.05). The findings showed that various pore architectures of HA/TCP scaffolds can be achieved using DLP 3D printing, which can be a valuable tool for optimizing bone-scaffold properties for specific clinical treatments. As the pore size only influenced bone regeneration in the initial stage, further studies are required for pore-size optimization to balance the initial bone regeneration and mechanical strength of the scaffold.

Computer-guided implant surgery for immediate implanting and loading: The STIL technique

A method is described for minimizing errors in positioning a surgical template during the insertion of implants immediately after extraction and the placement of interim prostheses with immediate loading. The technique, called sequential template immediate loading (STIL), uses modular templates to fix pins before extracting the teeth, thus giving a reliable position for the subsequent templates for inserting the implant and placing the interim prosthesis.

Computer-Aided Design/Computer-Aided Manufacturing Milling of Allogeneic Blocks Following Three-Dimensional Maxillofacial Graft Planning

Despite the advent of stereolithography in craniofacial surgery for creating surgical guides and custom synthetic scaffolds, little is known about the feasibility of computer-aided design/computer-aided manufacturing (CAD/CAM) milling of freeze-dried allogeneic bone blocks following previously designed volumetric graft plans. The aim of this technical report is to present a methodology for CAD/CAM milling to achieve the volume and shape of allogeneic bone blocks as estimated by using a virtual planning software. To perform the current methodology, an ex vivo simulation was performed. The milled allogeneic block presented satisfactory dimensional accuracy as compared with the respective three-dimensional virtual model.

Nanofibrous yarn reinforced HA-gelatin composite scaffolds promote bone formation in critical sized alveolar defects in rabbit model

Alveolar ridge resorption and crestal bone loss necessitate the use of bone graft substitutes for dental rehabilitation. The aim of this study was to compare the bone regenerative property of nanofibre incorporated two composite matrices (nanofibrous sheet layered matrix (CS-S) and nanofibrous yarn reinforced matrix (CS-Y)) in critical sized mandibular defect in a rabbit model (under load bearing scenario). Histological evaluation revealed continuous bone formation in the defect implanted with fibre reinforced scaffolds than those without fibres as well as commercial nanoHA-collagen graft. Interestingly, the mineralisation and the mineral density were significantly higher with nanoyarn reinforced scaffolds. Moreover, the compressive strength of new bone formed from CS-Y scaffolds was almost similar to that of native rabbit mandible. It can be concluded that the mechanical strength provided by three-dimensionally reinforced nanoyarns in the matrix could promote bone formation in load bearing mandibular region, and these can be proposed as a scaffold of choice for alveolar bone augmentation and dental rehabilitation.

Diode laser surgery in the treatment of oral proliferative verrucous leukoplakia associated with HPV-16 infection

Background

Proliferative verrucous leukoplakia (PVL) is an oral potentially malignant disorder, characterized by multifocal expression, progressive clinical evolution, and a high rate of malignant transformation. Evidence-based information regarding optimal PVL management is lacking, due to the paucity of data. The present report describes a case of PVL associated with HPV-16 infection and epithelial dysplasia treated by diode laser surgery, and the outcome of disease clinical remission over a 2-year follow-up period.

Case report

A 61-year-old Caucasian male with oral verrucous hyperkeratosis presented for diagnosis. The lesions were localized on the maxillary gingiva and palatal alveolar ridge. Multiple biopsy specimens have been taken by mapping the keratotic lesion area. Microscopic examination was compatible with a diagnosis of PVL with focal mild dysplasia, localized in the right maxillary gingiva. Polymerase chain reaction (PCR) was done for human papillomavirus (HPV) detection which revealed presence of HPV DNA, and the genotype revealed HPV 16 in the sample. The PVL in the right gingival area was treated on an outpatient basis by excision with a diode laser. This approach resulted in good clinical response and decreased morbidity over a 2-year follow-up period.

Conclusions

This case illustrates the benefit of a conservative approach by diode laser treatment than wide surgical excision for management of the PVL lesions associated with mild dysplasia and HPV-16 infection.

Silk Protein-Based Membrane for Guided Bone Regeneration

Silk derived from the silkworm is known for its excellent biological and mechanical properties. It has been used in various fields as a biomaterial, especially in bone tissue engineering scaffolding. Recently, silk protein-based biomaterial has been used as a barrier membrane scaffolding for guided bone regeneration (GBR). GBR promotes bone regeneration in bone defect areas using special barrier membranes. GBR membranes should have biocompatibility, biodegradability, cell occlusion, the mechanical properties of space-making, and easy clinical handling. Silk-based biomaterial has excellent biologic and mechanical properties that make it a good candidate to be used as GBR membranes. Recently, various forms of silk protein-based membranes have been introduced, demonstrating excellent bone regeneration ability, including osteogenic cell proliferation and osteogenic gene expression, and promoting new bone regeneration in vivo. In this article, we introduced the characteristics of silk protein as bone tissue engineering scaffolding and the recent application of such silk material as a GBR membrane. We also suggested future studies exploring additional uses of silk-based materials as GBR membranes.

Recent advances in the reconstruction of cranio-maxillofacial defects using computer-aided design/computer-aided manufacturing

With the development of computer-aided design/computer-aided manufacturing (CAD/CAM) technology, it has been possible to reconstruct the cranio-maxillofacial defect with more accurate preoperative planning, precise patient-specific implants (PSIs), and shorter operation times. The manufacturing processes include subtractive manufacturing and additive manufacturing and should be selected in consideration of the material type, available technology, post-processing, accuracy, lead time, properties, and surface quality. Materials such as titanium, polyethylene, polyetheretherketone (PEEK), hydroxyapatite (HA), poly-DL-lactic acid (PDLLA), polylactide-co-glycolide acid (PLGA), and calcium phosphate are used. Design methods for the reconstruction of cranio-maxillofacial defects include the use of a pre-operative model printed with pre-operative data, printing a cutting guide or template after virtual surgery, a model after virtual surgery printed with reconstructed data using a mirror image, and manufacturing PSIs by directly obtaining PSI data after reconstruction using a mirror image. By selecting the appropriate design method, manufacturing process, and implant material according to the case, it is possible to obtain a more accurate surgical procedure, reduced operation time, the prevention of various complications that can occur using the traditional method, and predictive results compared to the traditional method.

Maxillary resection for cancer, zygomatic implants insertion, and palatal repair as single-stage procedure: report of three cases

Background

Oronasal/antral communication, loss of teeth and/or tooth-supporting bone, and facial contour deformity may occur as a consequence of maxillectomy for cancer. As a result, speaking, chewing, swallowing, and appearance are variably affected. The restoration is focused on rebuilding the oronasal wall, using either flaps (local or free) for primary closure, either prosthetic obturator. Postoperative radiotherapy surely postpones every dental procedure aimed to set fixed devices, often makes it difficult and risky, even unfeasible. Regular prosthesis, tooth-bearing obturator, and endosseous implants (in native and/or transplanted bone) are used in order to complete dental rehabilitation. Zygomatic implantology (ZI) is a valid, usually delayed, multi-staged procedure, either after having primarily closed the oronasal/antral communication or after left it untreated or amended with obturator.

The present paper is an early report of a relatively new, one-stage approach for rehabilitation of patients after tumour resection, with palatal repair with loco-regional flaps and zygomatic implant insertion: supposed advantages are concentration of surgical procedures, reduced time of rehabilitation, and lowered patient discomfort.

Cases presentation

We report three patients who underwent alveolo-maxillary resection for cancer and had the resulting oroantral communication directly closed with loco-regional flaps. Simultaneous zygomatic implant insertion was added, in view of granting the optimal dental rehabilitation.

Conclusions

All surgical procedures were successful in terms of oroantral separation and implant survival. One patient had the fixed dental restoration just after 3 months, and the others had to receive postoperative radiotherapy; thus, rehabilitation timing was longer, as expected. We think this approach could improve the outcome in selected patients.

Custom-Made Synthetic Scaffolds for Bone Reconstruction: A Retrospective, Multicenter Clinical Study on 15 Patients

Purpose. To present a computer-assisted-design/computer-assisted-manufacturing (CAD/CAM) technique for the design, fabrication, and clinical application of custom-made synthetic scaffolds, for alveolar ridge augmentation. Methods. The CAD/CAM procedure consisted of (1) virtual planning/design of the custom-made scaffold; (2) milling of the scaffold into the exact size/shape from a preformed synthetic bone block; (3) reconstructive surgery. The main clinical/radiographic outcomes were vertical/horizontal bone gain, any biological complication, and implant survival. Results. Fifteen patients were selected who had been treated with a custom-made synthetic scaffold for ridge augmentation. The scaffolds closely matched the shape of the defects: this reduced the operation time and contributed to good healing. A few patients experienced biological complications, such as pain/swelling (2/15: 13.3%) and exposure of the scaffold (3/15: 20.0%); one of these had infection and complete graft loss. In all other patients, 8 months after reconstruction, a well-integrated newly formed bone was clinically available, and the radiographic evaluation revealed a mean vertical and horizontal bone gain of 2.1 ± 0.9 mm and 3.0 ± 1.0 mm, respectively. Fourteen implants were placed and restored with single crowns. The implant survival rate was 100%. Conclusions. Although positive outcomes have been found with custom-made synthetic scaffolds in alveolar ridge augmentation, further studies are needed to validate this technique.

Calcium Phosphate as a Key Material for Socially Responsible Tissue Engineering

Socially responsible technologies are designed while taking into consideration the socioeconomic, geopolitical and environmental limitations of regions in which they will be implemented. In the medical context, this involves making therapeutic platforms more accessible and affordable to patients in poor regions of the world wherein a given disease is endemic. This often necessitates going against the reigning trend of making therapeutic nanoparticles ever more structurally complex and expensive. However, studies aimed at simplifying materials and formulations while maintaining the functionality and therapeutic response of their more complex counterparts seldom provoke a significant interest in the scientific community. In this review we demonstrate that such compositional simplifications are meaningful when it comes to the design of a solution for osteomyelitis, a disease that is in its natural, non-postoperative form particularly prevalent in the underdeveloped parts of the world wherein poverty, poor sanitary conditions, and chronically compromised defense lines of the immune system are the norm. We show that calcium phosphate nanoparticles, which are inexpensive to make, could be chemically designed to possess the same functionality as a hypothetic mixture additionally composed of: (a) a bone growth factor; (b) an antibiotic for prophylactic or anti-infective purposes; (c) a bisphosphonate as an antiresorptive compound; (d) a viral vector to enable the intracellular delivery of therapeutics; (e) a luminescent dye; (f) a radiographic component; (g) an imaging contrast agent; (h) a magnetic domain; and (i) polymers as viscous components enabling the injectability of the material and acting as carriers for the sustained release of a drug. In particular, calcium phosphates could: (a) produce tunable drug release profiles; (b) take the form of viscous and injectable, self-setting pastes; (c) be naturally osteo-inductive and inhibitory for osteoclastogenesis; (d) intracellularly deliver bioactive compounds; (e) accommodate an array of functional ions; (f) be processed into macroporous constructs for tissue engineering; and (g) be naturally antimicrobial. All in all, we see in calcium phosphates the presence of a protean nature whose therapeutic potentials have been barely tapped into.