Radiographic evaluation of regenerated bone following poly(lactic-co-glycolic) acid/hydroxyapatite and deproteinized bovine bone graft in sinus lifting

Bovine-originated xenografts versus synthetic bone grafting materials in lateral maxillary sinus floor augmentation: A systematic review and meta-analysis

AIMS

This study aimed to systematically compare the patients undergoing lateral MSFA therapies utilizing bovine-originated xenografts versus varied synthetic bone grafting materials.

METHODS

Pubmed, Scopus, Embase, and Cochrane Library were searched up to April 2023, compensated by a manual search in selected journals. Studies reporting histological outcomes (residual bone graft, newly formed bone, non-mineralized tissue) and clinical outcomes (implant survival, ISQ value) were included. Several analyses were performed, including meta-analysis, sensitivity study, and Egger's regression tests.

RESULTS

Sixteen clinical/randomized control trials were included in this systematic review, among which 12 were enrolled in a meta-analysis. The percentage of newly formed bone within the grafted sinuses by hybrid HA/TCP was significantly higher than those by xenografts (WMD 2.85, 95%CI [0.72; 4.99]), but those grafted by pure HA (WMD -1.72, 95%CI [-3.15; -0.29]) or TCP (WMD -7.10, 95%CI [-13.02; -1.17]) were significantly lower than xenograft counterparts. The residual bone graft and non-mineralized tissue yielded by synthetic HA, TCP, and HA/TCP showed no significant differences with the xenograft group.

CONCLUSION

The chemistry of grafted bone substitutes in lateral MSFA influenced the quantity of newly formed bone. Those grafted with hybrid HA/TCP yielded the highest amount of new bone compared to bovine-originated HA. However, this influence was not significant on residual bone graft and non-mineralized tissue.

Exploring the potential of calcium-based biomaterials for bone regeneration in dentistry: a systematic review

INTRODUCTION

Regenerative medicine emerged as a promising strategy for addressing bone defects, with several bone grafts currently being used, including autografts, allografts, xenografts and alloplasts. Calcium-based biomaterials (CaXs), a well-known class of synthetic materials, have demonstrated good biological properties and are being investigated for their potential to facilitate bone regeneration. This systematic review evaluates the current clinical applications of CaXs in dentistry for bone regeneration.

EVIDENCE ACQUISITION

A comprehensive search was conducted to collect information about CaXs and their applications in the dental field over the last ten years. The search was limited to relevant articles published in peer-reviewed journals.

EVIDENCE SYNTHESIS

A total of 72 articles were included in this scoping review, with eight studies related to periodontology, 63 in implantology and three in maxillofacial surgery respectively. The findings suggest that CaXs hold promise as an alternative intervention for minor bone regeneration in dentistry.

CONCLUSIONS

Calcium-based biomaterials have shown potential as a viable option for bone regeneration in dentistry. Further research is warranted to fully understand their efficacy and safety in larger bone defects. CaXs represent an exciting avenue for researchers and clinicians to explore in their ongoing efforts to advance regenerative medicine.

Comparison of Different Techniques in Post-Extractive Socket Regeneration Using Autologous Tooth Graft: Histological and Clinical Outcomes

OBJECTIVE

 Post-extractive socket grafting techniques reduce alveolar ridge dimensional changes. Numerous graft materials have been suggested and a growing interest in tooth material has been observed as a valuable alternative to synthetic biomaterials or xenografts. Furthermore, different clinical procedures have been proposed for the wound closure of the post-extractive site. This study aims to compare histological and clinical outcomes of two different surgical techniques to seal the post-extractive site with the use of autologous demineralized extracted tooth as graft material.

MATERIALS AND METHODS

 Sixteen post-extractive socket without buccal and/or palatal bone walls, in sixteen healthy patients, were grafted with the autologous tooth material treated by the new Tooth Transformer device (Tooth Transformer, Milan, Italy). Alveolar socket preservation procedures were performed without flap elevation. Patients were randomly subdivided into two equal groups according to the site closure technique. In group A, the pedunculate tissue was used, while in group B ice cone technique. A bone samples were collected in each site after 4 months for histological analysis.

RESULTS

 No significant clinical differences among the different sealing techniques were observed. In both groups, the site was filled by new bone formation after 4 months of healing. The histological analysis revealed 46.1 ± 8.07% of bone volume, 9.2 ± 9.46% of residual graft, and 35.2 ± 12.36% of vital bone in group A, while group B shows 41.22 ± 5.88% of bone volume, 7.94 ± 7.54% of residual graft, and 31.7 ± 7.52% new bone. No statistical differences were detected (p > 0.05).

CONCLUSION

 Further studies with a large number of patients, and different observation periods will be needed to confirm the results of this pilot study; however, the interesting data obtained have shown how these techniques, mixed with the autologous dentin derived graft material, seem to promote bone regeneration and reduce physiological bone resorption during alveolar socket preservation treatments.

Long-term results of autologous periosteum-derived micro-grafts with poly(lactic-go-glycolic acid) in sinus lift augmentation surgeries: A 7-years follow-up observational study

INTRODUCTION AND IMPORTANCE

The study aimed to present the long-term results of autologous and homologous micrografts for bone regeneration aimed at positioning dental implants after sinus lift augmentation surgeries, by combining autologous Rigenera® micrografts with poly(lactic-go-glycolic acid).

CASE PRESENTATION

A total of 5 patients (2 males and 3 females) from 36 to 71 years were involved in the observational study. All the patients showed a good health status system (ASA1 and 2), according to their clinical history with neither system diseases, nor under medication able to interfere with osseointegration.

CLINICAL DISCUSSION

The radiographic evaluations, after the implant placement and during the continuous follow-up upto 7 years, were carried out through periapical endoral x-rays. The survival and implant success rate was 100 %. Histological analyses were performed after 3 and 7 months after the surgical procedure.

CONCLUSION

No adverse events have been observed that can be traced back to the use of autologous micrografts with poly(lactic-go-glycolic acid), showing safety and predictable results even in long term.

The Use of Lactide Polymers in Bone Tissue Regeneration in Dentistry-A Systematic Review

(1) Background: Different compositions of biodegradable materials are being investigated to successfully replace non-resorbable ones in bone tissue regeneration in dental surgery. The systematic review tried to address the question, "Can biodegradable polymers act as a replacement for conventional materials in dental surgery procedures?" (2) Methods: An electronic search of the PubMed and Scopus databases was conducted in October 2022. The following keywords were used: (lactide polymers) and (hydroxyapatite or fluorapatite) and (dentistry) and (regeneration). Initially, 59 studies were found. Forty-one studies met the inclusion criteria and were included in the review. (3) Results: These usually improved the properties and induced osteogenesis, tissue mineralisation and bone regeneration by inducing osteoblast proliferation. Five studies showed higher induction of osteogenesis in the case of biomaterials, UV-HAp/PLLA, ALBO-OS, bioresorbable raw particulate hydroxyapatite/poly-L-lactide and PLGA/Hap, compared to conventional materials such as titanium. Four studies confirmed improvement in tissue mineralisation with the usage of biomaterials: hydroxyapatite/polylactic acid (HA/PLA) loaded with dog's dental pulp stem cells (DPSCs), Coll/HAp/PLCL, PDLLA/VACNT-O:nHAp, incorporation of hydroxyapatite and simvastatin. Three studies showed an acceleration in proliferation of osteoblasts for the use of biomaterials with additional factors such as collagen and UV light. (4) Conclusions: Lactide polymers present higher osteointegration and cell proliferation rate than the materials compared. They are superior to non-biodegradable materials in terms of the biocompability, bone remodelling and healing time tests. Moreover, because there is no need of reoperation, as the material automatically degrades, the chance of scars and skin sclerosis is lower. However, more studies involving greater numbers of biomaterial types and mixes need to be performed in order to find a perfect biodegradable material.

Short term effects of rapid maxillary expansion on breathing function assessed with spirometry: A case-control study

BACKGROUND

The aim of this work is to evaluate changes following rapid maxillary expansion (RME) on breathing function in two groups of patients: mouth breathers and nasal breathers.

MATERIALS AND METHODS

Twenty-five oral breather patients (12 male, 13 female, mean age 15.2 ± 1.3), and 25 nasal breather patients (14 male, 11 female, mean age 15.3 ± 1.6) were treated with RME. Breathing function was evaluated by computerized spirometry. Forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), Tiffenau index (FEV1/ FVC ratio, IT%), forced expiratory flow at 25-75% of vital capacity (FEF 25-75%), and Tidal volume (TV) were assessed. Breathing function analysis was performed before RME and 6 and 12 months after RME during follow-up appointments. The Shapiro-Wilk test was used to assess whether data were normally distributed. As data were not normally distributed, Mann-Whitney U and Friedman tests were used to perform comparisons between treatment groups and within group comparisons, respectively.

RESULTS

Oral breathers and nasal breathers showed statistically significant differences in FVC, FEF 25-75%, and TV at T0. They did not present any statistically significant difference in FEV1 and IT% at the same time point.Statistically significant differences were noticed for all indices in the oral breather group after maxillary expansion, while the nasal breather group showed statistically significant differences only in FCV, FEF 25-75%, and TV after treatment.There were no statistically significant differences in all indices 12 months after maxillary expansion between the oral breather and nasal breather groups.

CONCLUSIONS

RME appeared to improve breathing function in both groups. Forced vital capacity (FVC), forced expiratory flow at 25-75% of vital capacity (FEF 25-75), and Tidal volume (TV) reached similar values in both groups after treatment with RME.

Mandibular Advancement Devices (MAD) as a Treatment Alternative for Obstructive Sleep Apnea Syndrome (OSAS)

Background:

Continuous Positive Airways Pressure therapy (CPAP) is the gold standard treatment of the Obstructive Sleep Apnea Syndrome (OSAS), however, the scarce adherence to the therapy requires the evaluation of other therapeutic alternatives.

Objective:

The aim of the present study was to assess the effectiveness of Mandibular Advancement Devices (MAD) in subjects affected by OSAS who had interrupted the treatment with CPAP and to make comparative evaluations.

Methods:

Eighteen subjects (15 males and 3 females), aged between 27 and 60 years, with a diagnosis of moderate to severe OSAS were included. Inclusion criteria: polysomnographic examination before treatment (T0) and after 1 month from the beginning of the therapy with CPAP(T1), interruption of the treatment due to loss of compliance, Epworth Sleepiness Scale (ESS) questionnaire filled out at T0 and T1. Subjects started the treatment with MAD and polysonnographic examination was prospectively executed after 3 months (T2) and 1 year (T3). One-way analysis of the variance (ANOVA) was used to compare data of polysonnographic examination performed at T0, T1, T2 and T3 as well as the differences of ESS scores recorded at different timing.

Results:

Compared to baseline (T0), all functional parameters tested showed statistically significant differences at T1, T2 and T3 (p < 0.001), meanwhile no differences were found between data recorded after therapy with MAD (T2 and T3) and with CPAP (T1). Similar results were also found with the score of ESS among different timelines (p < 0.001).

Conclusion:

These findings suggest that MAD could be a valid alternative for the treatment of OSAS in those patients with scarce adherence to the CPAP therapy.

Invisalign appliance: aesthetic and efficiency

BACKGROUND

The patients' request for treatment with clear aligners is constantly increasing. The aligners permit to the clinicians a valid way to solve a lot of orthodontic cases but the patients' compliance and the clinicians' capabilities and knowledge of the technique is fundamental for the outcome.

METHODS

Seventy-two digital models of 18 consecutive patients treated with Invisalign and Smart Track aligners for 14 weeks were analyzed. The operator positioned 24 points on each model and were obtained the values of arch depth and perimeter of arch before and after the treatment. The variations of measurement were calculated with t student test.

RESULTS

A decrease of arch depth and perimeter was found from t0 to t1 and the most relevant difference was observed in the upper arch depth with a decrease of 1.3 mm and in the upper arch perimeter with a difference of 1.1 mm.

CONCLUSIONS

There was always a decrease of the values of arch depth and arch perimeter at the end of the treatment, especially in the upper arch. These changes must be considered by the clinicians to perform a better treatment to obtain the most predictable results and a patient's higher satisfaction.

Stannous Fluoride Preventive Effect on Enamel Erosion: An In Vitro Study

The aim of this in vitro study was to evaluate the effects of a single dose application of two daily toothpastes on enamel exposed to acid attack. The research was conducted on human molars enamel fragments (n = 72). The two different toothpastes active ingredients were sodium fluoride (NaF) and stannous fluoride (SnF₂). They were compared in protecting the surface of the enamel exposed to three acids: citric acid, lactic acid and hydrochloric acid. A spectrophotometer was used to measure the calcium ions and phosphate released in the solutions by the enamel specimens. Afterward, ionic concentrations were analyzed through the t-Student test, in order to estimate the significance level (p < 0.05) of the solubility differences obtained between the treatment and control groups. Finally, sample surfaces were analyzed with scanning electron microscopy and X-ray energy dispersive spectroscopy (SEM/EDX). The two analyzed toothpastes did not reveal any statistically significant variation in the release of calcium and phosphate (p > 0.05). Nevertheless, acid-resistant deposits were detected in samples treated with stannous fluoride and exposed to lactic acid, though the presence of tin ion deposits on samples treated with stannous fluoride was not shown. A single dose of a fluoride-based toothpaste before different acids attack, in simulated oral cavity conditions, did not show a significant preventive effect.

Autologous Tooth Graft after Endodontical Treated Used for Socket Preservation: A Multicenter Clinical Study

The aim of the study was to evaluate the tooth extracted use as autologous tooth graft after endodontic root canal therapies used for socket preservation. To this purpose, the Tooth Transformer shredding and decontamination machine has been used. The graft obtained in this way, was inserted at the time of the extraction or at a second surgery altogether with the chosen regenerative therapy. This clinical trial enrolled patients with post-estractive defects requiring the restoration bone dimension and shape in the maxillary and mandibular zone. In addition, 98 patients with 119 extraction sockets were enrolled across 10 standardized centers. An innovative preparation method, using the dedicated automated device Tooth Transformer, able to transform autologous teeth in suitable grafting material, has been used. The extracted tooth was cleaned and treated using a Tooth Transformer and made a socket preservation. Thirteen Biopsies were realized to analyze the histologic outcomes at the average time of four months to demonstrate that the autologous tooth graft made from root after endodontic therapy should be used in human bone regeneration as graft for dental implant placement.

Poly D,L-Lactide-Co-Glycolic Acid Grafting Material in Sinus Lift

The poly D,L-lactide-co-glycolic acid (PLGA) is a copolymer used in many therapeutic devices for its high rates of biodegradability and biocompatibility. The principal aim of the research was to evaluate the new bone formation, after 16 (T1) and 28 weeks (T2), in sheep maxillary sinus lift in vivo model using PLGA.Computerized tomography analysis, X-ray microanalysis, and scanning electron microscope analysis of secondary electrons (SE) and the backscattered electrons (BSE) of the samples were detected.After 28 weeks, the computed tomography analysis showed a 22% increase of UH density in the grafting areas. The X-ray microanalysis of the samples showed calcium and phosphorus increase at T1 and T2 follow-up period and the carbon and oxygen concentration decrease. The SE evaluation showed a rapid superficial resorption of the biomaterials at T1 and a completely bone reorganization of biomaterial at T2. The BSE analysis confirmed the SE data and showed the direct and intimate contact between bone and PLGA with a higher calcification in T2 compared to T1.Certainly, still other experiments and a larger number of samples will be necessary to be analyzed to determine the behavior of the PLGA in the bone regeneration; however, the PLGA used in maxillary sinus lift animal model, seem to promote new bone formation that continues increase at 28 weeks after grafting.

Detection of peri-implant inflammation by the use of a matrix metalloproteinase-8 chair-side test

BACKGROUND

Active matrix metalloproteinase-8 (MMP-8) enzymes are associated with inflammation and the degradation of implant-supporting tissues. A high concentration of these enzymes in the peri-implant sulcular fluid (PISF) has been associated with a pathological condition. The aim of the present study was to evaluate the ability of a chair-side MMP-8 test to individuate pathological peri-implant site. The working hypothesis is that positive response to MMP-8 test corresponds to pathological values of periodontal indexes. A secondary working hypothesis is that PISF sampling method influences the test accuracy.

METHODS

Fifty implants from 50 patients were evaluated during scheduled follow-up appointments in a clinical setting using the MMP-8 chair-side test and periodontal indices (probing depth, bleeding on probing, plaque index and peri-implant inflammation index). Two methods of PISF sampling were tested.

RESULTS

The MMP-8 test demonstrated significant diagnostic capacity and good sensitivity and accuracy regarding indices of bleeding on probing, plaque index, and peri-implant inflammation index but fair agreement.

CONCLUSIONS

Further studies should be performed to better define the interpretation of the MMP-8 chair-test results and their correlation to peri-implant indexes.

Sinus floor elevation using particulate PLGA-coated biphasic calcium phosphate bone graft substitutes: A prospective histological and radiological study

BACKGROUND

Poly (lactic-co-glycolic acid) (PLGA) is widely used for the development of delivery systems for drugs and therapeutic biomolecules in tissue engineering applications. Particles of biphasic calcium phosphate can be covered by PLGA to change their manipulating characteristics.

PURPOSE

Aim of this study was to investigate the radiological and histomorphometric results of the use of PLGA-coated biphasic calcium phosphate granules in sinus floor elevation and to analyze the underlying molecular processes by immunohistochemical staining.

MATERIALS AND METHODS

A randomized clinical study was designed to include patients in need of sinus floor elevation. Patients were assigned to receive either PLGA-coated biphasic calcium phosphate particles (group I) or the equivalent but noncoated particles (group II). Cone beam computed tomography (CBCT) scans were performed before and 6 months after the procedure to assess the bone height gain. At the time of implant placement, bone core biopsies were obtained at the site of implant placement. Histological sections were subjected to histomorphometric and immunohistochemical evaluation of differentiation markers (Musashi-1 [MSI1]).

RESULTS

No statistically significant differences were observed between groups for the radiologic parameters. No differences were observed histologically or histomorphometrically. However, PLGA-coated particles (group I) were more colonized by MSI1-positive osteoblast precursors (P = 0.0001, chi-squared test) and were penetrated by more CD34-positive vascular structures (P = 0.001, chi-squared test) than noncoated particles (group II).

CONCLUSIONS

PLGA-coated particles are associated with more MSI11-positive cells and more extensive microvascularization than noncoated particles.

Covalently-Linked Hyaluronan versus Acid Etched Titanium Dental Implants: A Crossover RCT in Humans

Biochemical modification of titanium surfaces (BMTiS) entails immobilization of biomolecules to implant surfaces in order to induce specific host responses. This crossover randomized clinical trial assesses clinical success and marginal bone resorption of dental implants bearing a surface molecular layer of covalently-linked hyaluronan in comparison with control implants up to 36 months after loading. Patients requiring bilateral implant rehabilitation received hyaluronan covered implants in one side of the mouth and traditional implants in the other side. Two months after the first surgery, a second surgery was undergone to uncover the screw and to place a healing abutment. After two weeks, the operator proceeded with prosthetic procedures. Implants were evaluated by periapical radiographs and the crestal bone level was recorded at mesial and distal sites—at baseline and up to 36 months. One hundred and six implants were positioned, 52 HY-coated, and 48 controls were followed up. No differences were observed in terms of insertion and stability, wound healing, implant success, and crestal bone resorption at any time considered. All interventions had an optimal healing, and no adverse events were recorded. This trial shows, for the first time, a successful use in humans of biochemical-modified implants in routine clinical practice and in healthy patients and tissues with satisfactory outcomes.

Preliminary Results of Bone Regeneration in Oromaxillomandibular Surgery Using Synthetic Granular Graft

Traumatic, neoplastic, inflammatory, or infective dental removal promotes a gradual resorption process of bone which leads to a “nonuse” atrophy of the alveolar ridges. Many techniques allows restoring an appropriate bone thickness, but nowadays the attention is focused on the use of natural or synthetic grafts. Numerous studies have been conducted to develop and test new synthetic materials. In this article, the authors report their experience using a synthetic bone substitute in combination with Platelet Rich Fibrin (PRF). This technique was applied in different zones of the maxillomandibular district. The procedure showed a very satisfying bone regeneration without important complications.

Geometric distortion of panoramic reconstruction in third molar tilting assessments: a comprehensive evaluation

OBJECTIVES:

To evaluate the geometric distortion of tilting of mandibular third molars with respect to second molars on panoramic reconstruction.

METHODS:

Cone-beam CT (CBCT) reconstructions of 160 third molars, obtained due to an indication of risk of inferior alveolar nerve damage during surgery, were used. CBCT-reconstructed panoramic images were used as bi-dimensional (2D) images, to avoid distortions other than geometric distortions. The angle between the second and the third molar was measured in 2D and three-dimensional (3D) images. Student's t-test was used to assess the null-hypothesis of no difference between 2D and 3D measurements.

RESULTS:

A significant mean difference (-2.3° ± 6.3°) between 2D and 3D measurements was found, with an absolute error of 3.6° ± 5.7° and a relative error of 10%. These findings comprehensively explain the geometric distortion on panoramic radiographs.

CONCLUSIONS:

Although a widely used and undoubtedly useful tool for diagnosis and surgical planning of mandibular third molar extractions, panoramic reconstruction are biased from geometric distortion that may influence surgical planning.

The use of hydroxyapatite bone substitute grafting for alveolar ridge preservation, sinus augmentation, and periodontal bone defect: A systematic review

OBJECTIVES

We determined and structurally analyzed the reported effect of hydroxyapatite (HA) bone substitute on alveolar bone regeneration. To the best of our knowledge, no systematic reviews have previously reported the bone regenerative effect of the HA bone substitute.

MATERIALS AND METHODS

A literature search was performed for articles published up to August 2015 using MEDLINE with the search terms "hydroxyapatite," "bone regeneration," and "alveolar bone" as well as their known synonyms. The inclusion criteria were set up for human trials with at least five patients. The literature search, eligible article selection, and data extraction were independently performed by two readers, and their agreement was reported by κ value.

RESULTS

Of the 504 studies found using the MEDLINE literature search, 241 were included for further steps (inter-reader agreement, κ = 0.968). Abstract screening yielded 74 studies (κ = 0.910), with 42 completely fulfilling the inclusion criteria (κ = 0.864). In a final step, 42 studies were further analyzed, with 17 and 25 studies with and without statistical analysis, respectively. The 17 studies reporting similar outcome measures were compared using the calculated 95% confidence intervals. The effect of HA on ridge preservation could not be evaluated.

CONCLUSIONS

The use of the HA bone substitute interfered with the normal healing process, with significant differences found for sinus augmentation but not for periodontal bone defects. Thus, a bone substitute with optimal bone regenerative properties for alveolar ridge or socket preservation, sinus augmentation, and periodontal bony defect should be developed.

Maxillary Sinus Lift Using Autologous Periosteal Micrografts: A New Regenerative Approach and a Case Report of a 3-Year Follow-Up

This case report discusses about an innovative bone regeneration method that involves the use of autologous periosteal micrografts, which were used for a maxillary sinus floor lift in a 52-year-old female patient. This method allows for harvesting of a graft that is to be seeded on a PLGA scaffold and involves collection of a very little amount of palatal periosteal tissue in the same surgical site after elevation of a flap and disaggregation of it by using a Rigenera® filter. Histological samples collected at the time of implant installation demonstrate a good degree of bone regeneration. The clinical and radiographic outcomes at the 3-year follow-up visit showed an adequate stability of hard and soft tissues around the implants. This report demonstrates the possibility to obtain a sufficient quality and quantity of bone with a progenitor cell-based micrograft and in turn make the site appropriate for an implant-supported rehabilitation procedure, with stable results over a period of two years.

Long-Term Effects of Acute Myeloid Leukemia Treatment on the Oral System in a Pediatric Patient

Introduction:

Acute Myeloid Leukemia (AML) in pediatric patients is a serious disease, although, for the subgroup of patients who receive proper treatment, a long-term survival rate above 50% is typical. The cycles of chemo- and radiotherapy used to treat AML can impair dental development.

Case Report:

Herein, we describe the oral condition of a 25-year-old male patient treated for AML with chemo- and radiotherapy from 5 to 7 years of age; his AML has remained in remission for the past 18 years. He had lost only one permanent tooth, but the remaining teeth demonstrated serious deformations and radicular hypoplasia. Two teeth required immediate extraction and subsequent replacement by implant-supported crowns. We found that the decayed, missing, filled teeth (DMFT) index was not representative of the real oral condition. Here, we report the full case and provide a brief review of the literature.

Conclusion:

Antitumor treatment of pediatric leukemia can induce total impairment of dental development and function. These adverse effects may become clinically evident many years after the resolution of cancer, and can be significantly detrimental to the patient’s quality of life.

Evaluation of Poly(Lactic-co-glycolic) Acid Alone or in Combination with Hydroxyapatite on Human-Periosteal Cells Bone Differentiation and in Sinus Lift Treatment

Most recent advances in tissue engineering in the fields of oral surgery and dentistry have aimed to restore hard and soft tissues. Further improvement of these therapies may involve more biological approaches and the use of dental tissue stem cells in combination with inorganic/organic scaffolds. In this study, we analyzed the osteoconductivity of two different inorganic scaffolds based on poly (lactic-co-glycolic) acid alone (PLGA-Fisiograft) or in combination with hydroxyapatite (PLGA/HA-Alos) in comparison with an organic material based on equine collagen (PARASORB Sombrero) both in vitro and in vivo. We developed a simple in vitro model in which periosteum-derived stem cells were grown in contact with chips of these scaffolds to mimic bone mineralization. The viability of cells and material osteoconductivity were evaluated by osteogenic gene expression and histological analyses at different time points. In addition, the capacity of scaffolds to improve bone healing in sinus lift was examined. Our results demonstrated that the osteoconductivity of PLGA/HA-Alos and the efficacy of scaffolds in promoting bone healing in the sinus lift were increased. Thus, new clinical approaches in sinus lift follow-up should be considered to elucidate the clinical potential of these two PLGA-based materials in dentistry.

Autologous Periosteum-Derived Micrografts and PLGA/HA Enhance the Bone Formation in Sinus Lift Augmentation

Sinus lift augmentation is a procedure required for the placement of a dental implant, whose success can be limited by the quantity or quality of available bone. To this purpose, the first aim of the current study was to evaluate the ability of autologous periosteum-derived micrografts and Poly(lactic-co-glycolic acid) (PLGA) supplemented with hydroxyl apatite (HA) to induce bone augmentation in the sinus lift procedure. Secondly, we compared the micrograft's behavior with respect to biomaterial alone, including Bio-Oss® and PLGA/HA, commercially named Alos. Sinus lift procedure was performed on 24 patients who required dental implants and who, according to the study design and procedure performed, were divided into three groups: group A (Alos + periosteum-derived micrografts); group B (Alos alone); and group C (Bio-Oss® alone). Briefly, in group A, a small piece of periosteum was collected from each patient and mechanically disaggregated by Rigenera® protocol using the Rigeneracons medical device. This protocol allowed for the obtainment of autologous micrografts, which in turn were used to soak the Alos scaffold. At 6 months after the sinus lift procedure and before the installation of dental implants, histological and radiographic evaluations in all three groups were performed. In group A, where sinus lift augmentation was performed using periosteum-derived micrografts and Alos, the bone regeneration was much faster than in the control groups where it was performed with Alos or Bio-Oss® alone (groups B and C, respectively). In addition, the radiographic evaluation in the patients of group A showed a radio-opacity after 4 months, while after 6 months, the prosthetic rehabilitation was improved and was maintained after 2 years post-surgery. In summary, we report on the efficacy of periosteum-derived micrografts and Alos to augment sinus lift in patients requiring dental implants. This efficacy is supported by an increased percentage of vital mineralized tisssue in the group treated with both periosteum-derived micrografts and Alos, with respect to the control group of Alos or Bio-Oss® alone, as confirmed by histological analysis and radiographic evaluations at 6 months from treatment.

Emerging Perspectives in Scaffold for Tissue Engineering in Oral Surgery

Bone regeneration is currently one of the most important and challenging tissue engineering approaches in regenerative medicine. Bone regeneration is a promising approach in dentistry and is considered an ideal clinical strategy in treating diseases, injuries, and defects of the maxillofacial region. Advances in tissue engineering have resulted in the development of innovative scaffold designs, complemented by the progress made in cell-based therapies. In vitro bone regeneration can be achieved by the combination of stem cells, scaffolds, and bioactive factors. The biomimetic approach to create an ideal bone substitute provides strategies for developing combined scaffolds composed of adult stem cells with mesenchymal phenotype and different organic biomaterials (such as collagen and hyaluronic acid derivatives) or inorganic biomaterials such as manufactured polymers (polyglycolic acid (PGA), polylactic acid (PLA), and polycaprolactone). This review focuses on different biomaterials currently used in dentistry as scaffolds for bone regeneration in treating bone defects or in surgical techniques, such as sinus lift, horizontal and vertical bone grafts, or socket preservation. Our review would be of particular interest to medical and surgical researchers at the interface of cell biology, materials science, and tissue engineering, as well as industry-related manufacturers and researchers in healthcare, prosthetics, and 3D printing, too.