Circular RNA-Mediated Regulation of Oral Tissue-Derived Stem Cell Differentiation: Implications for Oral Medicine and Orthodontic Applications.

Circular RNAs (circRNAs) are a novel class of endogenous non-coding RNAs (ncRNAs) which unlike linear RNAs, have a covalently closed continuous loop structure. circRNAs are found abundantly in human cells and their biology is complex. They feature unique expression to different types of cells, tissues, and developmental stages. To the present, the functional roles of circular RNAs are not fully understood. They reportedly act as microRNA (miRNA) sponges, therefore having key regulatory functions in diverse physiological and pathological processes. As for dentistry field, lines of evidence indicate that circRNAs play vital roles in the odontogenic and osteogenic differentiation of dental pulp stem cells (DPSCs) and periodontal ligament stem cells (PDLSCs). Abnormal expression of circRNAs have been found in other areas of pathology frequently reflected also in the oral environment, such as inflammation or bone and soft tissue loss. Therefore, circRNAs could be of significant importance in various fields in dentistry, especially in bone and soft tissue engineering and regeneration. Understanding the molecular mechanisms occurring during the regulation of oral biological and tissue remodeling processes could augment the discovery of novel diagnostic biomarkers and therapeutic strategies that will improve orthodontic and other oral therapeutic protocols.

Biocompatibility and histological responses of eggshell membrane for dental implant-guided bone regeneration.

Guided bone regeneration (GBR) utilizing eggshell membrane (ESM) as a potential biomaterial for dental implant therapy augmentation was explored in this study. ESM, an environmentally friendly waste product, possesses collagen-rich characteristics. The biocompatibility and histological responses of ESM were investigated in a rat model. Twelve young adult Wistar rats were used in this study. ESM samples were implanted in subcutaneous and intramuscular pockets, and samples were collected at 48 hours, 4 weeks, and 8 weeks post-implantation. Histological analysis revealed the changes in ESM over time. Results showed that ESM maintained its structural integrity, induced a moderate cellular response, and exhibited slow degradation, indicating potential biocompatibility. However, the lack of organized collagen arrangement in ESM led to the formation of irregular and polymorphic spaces, allowing cell migration. Encapsulation of ESM by newly proliferating collagen fibers and multinucleated giant cells was observed at later time points, indicating a foreign body reaction. Crosslinking might improve its performance as a separation membrane, as it has the potential to resist enzymatic degradation and enhance biomechanical properties. In conclusion, ESM demonstrated biocompatibility, slow degradation, and lack of foreign body reaction. While not suitable as a complete separation membrane due to irregular collagen arrangement, further research involving crosslinking could enhance its properties, making it a viable option for guided bone regeneration applications in dental implant therapy. This study highlights the potential of repurposing waste materials for medical purposes and underscores the importance of controlled collagen structure in biomaterial development.

High-Frequency Ultrasound in Diagnosis and Treatment of Non-Melanoma Skin Cancer in the Head and Neck Region.

Non-melanoma skin cancer is one of the most frequently diagnosed cancers in the human body and unfortunately the incidence continues to increase. NMSC is represented by the basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs), which are the most prevalent forms, and basosquamous cell carcinomas (BSC) together with Merkel cell carcinoma (MCC), which are rare types but with a very aggressive pattern and poor prognosis. The pathological diagnosis is hard to assess without a biopsy, even by the dermoscopy. Moreover, the staging can be problematic because there is no access clinically to the thickness of the tumor and the depth of the invasion. The aim of this study was to evaluate the role of ultrasonography (US), which is a very efficient imaging method, non-irradiating and cheap, in diagnosis and treatment of non-melanoma skin cancer in the head and neck region. Thirty-one patients with highly suspicious malignant lesions of the head and neck skin were evaluated in the Oral and Maxillo-facial Surgery Department and Imaging Department in Cluj Napoca, Romania. All tumors were measured with three transducers: 13 MHz, 20 MHz and 40 MHz. Doppler examination and elastography were also used. The length, width, diameter, thickness, the presence of necrosis, status of regional lymph nodes, the presence of hyperechoic spots, strain ratio and vascularization were all recorded. After that, all patients were treated by surgical resection of the tumor and reconstruction of the defect. Immediately after surgical resection, all tumors were measured again after the same protocol. The resection margins were evaluated by all three types of transducers in order to detect malignant involvement and the results were compared with the histopathological report. We found that the 13 MHz transducers offered a big picture of the tumor but the level of details, in the form of the presence of the hyperechoic spots, is reduced. We recommend this transducer for evaluation of surgical margins or for the large skin tumors. The 20 and 40 MHz transducers are better for viewing the particularities of malignant lesions and for an accurate measurement; however, in the case of large size lesions, assessing all three dimensions of the tumor can be difficult. The intralesional hyperechoic spots are present in case of BCC and they can be used for differential diagnosis of BCC.

The Value of Multiparametric Magnetic Resonance Imaging in the Preoperative Differential Diagnosis of Parotid Gland Tumors.

BACKGROUND: The aim of the present study was to determine the value of multiparametric MRI in the preoperative differential diagnosis of parotid tumors, which is essential for therapeutic strategy selection. METHODS: A three-year prospective study was conducted with 65 patients. Each patient was investigated preoperatively with multiparametric MRI and surgical excision of the tumor was performed. The preoperative imaging diagnosis was compared with the histopathological report. Several MRI parameters were analyzed, including T1 and T2 weighted image (WI), apparent diffusion coefficient (ADC), time to peak (TTP), and the time intensity curve (TIC). RESULTS: In the differential diagnosis of benign from malignant tumors, T2WI and ADC showed statistically significant differences. Multiparametric MRI had a sensitivity, specificity, and accuracy of 81.8%, 88.6% and 92.3%, respectively. All of the studied parameters (T1, T2, TIC, TTP, ADC) were significantly different in the comparison between pleomorphic adenomas and Warthin tumors. With reference to the scope of this study, the conjunction of multiparametric and conventional MRI demonstrated a sensitivity, specificity, and accuracy of 94.1%, 100%, and 97.8%, respectively. CONCLUSIONS: Morphological analysis using conventional MRI combined with diffusion-weighted imaging (DW) and dynamic contrast-enhanced (DCE) multiparametric MRI improved the preoperative differential diagnosis of parotid gland tumors.

Benign Pediatric Jawbone Lesions: A 10-Year Clinical and Radiological Pilot Study.

This study aimed at presenting a retrospective longitudinal analysis of the pediatric jaw lesions treated at the Oral and Maxillofacial Surgery Clinic in Cluj-Napoca, Romania, over a timeframe of ten years (2012 to 2022). The clinical and radiological characteristics of the jawbone lesions, the treatment outcome, and the recurrence incidence were described. All consecutive patients aged below 18 years, with histologically diagnosed odontogenic tumors (OTs), nonodontogenic tumors (non-OTs), or odontogenic cysts (OCs) were included. Age, dentition type, clinical symptoms, preoperative and postoperative radiological tests, histological diagnosis, treatment, and follow-up information one year following the diagnoses were all examined. Eighty-two cases were included. The ratio of men to women was 1.15:1, with the mandible predominating by 64.4%. Inflammatory radicular cysts predominated in 31.7% of cases. A total of 42.68% of the patients were asymptomatic. Enucleation was the most frequent surgical technique (45.1%), followed by cystectomies (28%) and marsupialization (14.6%). The overall recurrence rate was 7.3%; the most recurrent histopathological lesion was the odontogenic keratocyst. This study sheds new light on the clinical and radiological characteristics, treatment outcomes, and recurrence rate of juvenile jawbone lesions in children and adolescents. The diagnosis and treatment of jawbone lesions in children and adolescents can be enhanced with the use of epidemiological, clinical, and imagistic information.

The Role of miRNA-221 and miRNA-34a in Non-Melanoma Skin Cancer of the Head and Neck Region.

Non-melanoma skin cancer (NMSC) is one of the most frequent types of malignancy in the human body with an increasing incidence. Short, non-coding RNA molecules called microRNAs (miRNAs) can control post-transcriptional gene expression and they have a significant role in several physiological cellular processes and pathologies, including cancer. Depending on the functions of the genes, miRNAs may function as oncogenes or tumor suppressors. The aim of this paper was to describe the role of miRNA-34a and miRNA-221 in head and neck NMSC. Thirty-eight NMSC match paired (tumor and adjacent) tissue samples were evaluated by qRT-PCR. Total RNA was extracted and isolated from tissue samples using the phenol-chloroform (Trireagent) method according to the manufacturer's protocol. The concentration of RNA was measured by a NanoDrop-1000 spectrophotometer. The expression level of each miRNA was calculated by threshold cycle. For all statistical tests, the 0.05 significance level was used and two-tailed p values. All analyses were conducted in an R environment for statistical computing and graphics. We found the miRNA-221 being overexpressed in squamous cell carcinoma (SCC) (p < 0.05), basal cell carcinoma (BCC) and basosquamous cell carcinoma (BSC) compared with adjacent normal tissue. Additionally, the levels of miRNA-221 were two times higher (p < 0.05) in cases where the excision of the tumor was done with positive margins (R1), which means that we are the first to highlight the potential role of miRNA-221 in the microscopical local invasion. Mi-RNA-34a expression was altered in the malignant tissue compared with the adjacent normal one both in BCC and SCC but not statistically significantly. In conclusion, NMSC are challenging because of their increasing incidence and rapidly evolving development and discovering their molecular mechanisms of action lead us to understand tumorigenesis and evolution, while also contributing to the implementation of novel therapeutic keys.

Characterization of eggshell as a bio-regeneration material.

Objective: The objective of this study was to identify and summarize the characteristic features of eggshell for regeneration purpose in oral surgery procedures. Methods: A review of literature was undertaken based on the PubMed database. A search to reveal the current state of knowledge and the current uses of the eggshell as a biomaterial was performed. The characteristics of the materials, the specific use, the procedure and the outcome were extracted from the articles. Results: The materials have been found to be used in humans, animals, and in vitro studies. There is a wide use regarding oral surgery especially in experimental models. There have also been attempts to enhance certain properties and improve the capabilities of eggshell as a biomaterial. There is yet a commercial product to be developed and approved for human use. Conclusions: Eggshell can be an important biowaste which can be of use in guided bone regeneration procedures, but it has not yet entered the commercial phase and approval through official regulation channels.

Recovery following Orthognathic Surgery Procedures-A Pilot Study.

This study aims at evaluating and categorizing patients' objective and subjective postoperative recovery symptoms after bimaxillary orthognathic surgery assigning the healing process. The patients were monitored throughout the recovery process, and their symptoms were managed. A prospective, observational study was performed. Patients with Class II and III malocclusion (aged 18 to 35) were evaluated and monitored preoperatively, and postoperatively at 48 h, 2 weeks, 1 month, and 3 months postsurgery. A questionnaire was used to assess pain and anesthesia/hypoesthesia. The most common objective and subjective signs that were correlated with the healing process were edema, hematoma, trismus, pain, and anesthesia/hypoesthesia. Edema peaked at 48−72 h postoperatively (distance between eye's external canthus and gonion, mean difference = 4.53, between tragus and cheilion, mean difference = 7, between tragus and gnathion, mean difference = 4.65, p < 0.001); mouth opening amplitude was significantly decreased during the first two weeks postsurgery (class II, mean difference = 32.42, p = 0.006, class III, mean difference = 44.57, p < 0.001), but it steadily and considerably improved over three months. The nose tended to widen postsurgery. The most severe pain experienced by patients was of medium intensity in the mandibular body, described as pressure, and usually did not spread. Patients were most severely and persistently impacted by anesthesia/hypoesthesia.

The quality of life after cleft lip and palate surgery.

Background and aims: Labio-maxillo-palatal clefts represent one of the most common congenital malformations, which manifests through aesthetic, functional and psycho-social alterations. The long course of multidisciplinary treatments represent a psycho-emotional and financial burden for both the patient and his family, being an important factor in the complex management of these patients.The study aims to assess the quality of life of parents of children with clefts and the psychosocial impact on the family and society. Methods: The study included 40 subjects who met the inclusion criteria for this study. Following patient informed consent and the approval of the ethics committee, the data were collected by applying the quality-of-life evaluation questionnaire. The evaluation was performed using the Likert scale (1 - not at all to 5 - very satisfactory), and the data were statistically processed. Results: Most of the questionnaires were completed by the mother, who accompanied the child to the regular check-up; 58% of parents believe that their social life is not affected by having a child with a cleft, and 83% say that interfamilial relationships have not been affected. Most parents consider that the postoperative result was very good, which led to improved psycho-social integration of the child. Conclusions: The study confirmed an acceptable quality of life for the children's parents, which was not influenced by the family presence of a child with a cleft. At the same time, the excessive care of the parents for the child with the cleft was confirmed. The postoperative improvement of the aesthetic aspect led to a much better psycho-emotional integration of the child in the society.

The usefulness of cone beam computed tomography according to age in cleft lip and palate.

The current study aimed to evaluate the usefulness of cone beam computed tomography (CBCT) examination in cleft children and adolescents, the age of the first CBCT exposure, and the criteria that justified the first CBCT exposure. A number of 229 non-syndromic cleft subjects aged between 0-22 years receiving treatment in the same specialized surgical center in orofacial cleft treatment were studied. A cleft group of 64 cleft lip and palate (CLP) children with at least one CBCT exposure was identified based on CBCT records. Parameters related to diagnosis and treatment planning in cleft deformity were considered dental anomalies and bone morphology changes. The examiners assessed whether the treatment option was necessary, not necessary, or could not be evaluated at the age of CBCT exposure. A number of thirty-nine unilateral clefts and fifteen bilateral clefts were identified. Posterior palatal cleft was present in six children (mean age: 15.03±5.55 years; male/female ratio: 1/0.8). Alveolar bone morphology changes were found in 90.58% of cases; jaw relationship changes in 71.82%; nasal fossa morphology changes in 74.99%; airway obstruction in 49.98% and maxillary asymmetry in 87.48%. Orthodontic planning was necessary for 85.93% of CLP patients, and orthognathic surgery in 39.05%. The usefulness of CBCT in patients with CLP varied with age, with reduced value for the evaluation of impaction and root resorption under the age of ten.

Prospective Evaluation of Intraorbital Soft Tissue Atrophy after Posttraumatic Bone Reconstruction: A Risk Factor for Enophthalmos.

Orbital fractures are a common finding in facial trauma, and serious complications may arise when orbital reconstruction is not performed properly. The virtual planning can be used to print stereolithographic models or to manufacture patient-specific titanium orbital implants (PSIs) through the process of selective laser melting. This method is currently considered the most accurate technique for orbital reconstruction. Even with the most accurate techniques of bone reconstruction, there are still situations where enophthalmos is present postoperatively, and it may be produced by intraorbital soft tissue atrophy. The aim of this paper was to evaluate the orbital soft tissue after posttraumatic reconstruction of the orbital walls' fractures. Ten patients diagnosed and treated for unilateral orbital fractures were included in this prospective study. A postoperative CT scan of the head region with thin slices (0.6 mm) and soft and bone tissue windows was performed after at least 6 months. After data processing, the STL files were exported, and the bony volume, intraorbital fat tissue volume, and the muscular tissue volume were measured. The volumes of the reconstructed orbit tissues were compared with the volumes of the healthy orbit tissues for each patient. Our findings conclude that a higher or a lower grade of fat and muscular tissue loss is present in all cases of reconstructed orbital fractures. This can stand as a guide for primary or secondary soft tissue augmentation in orbital reconstruction.

Is miRNA Regulation the Key to Controlling Non-Melanoma Skin Cancer Evolution?

Non melanoma skin cancer (NMSC) is one of the most common types of skin cancer. It has a number of subtypes, which include basal cell carcinoma, cutaneous squamous cell carcinoma and Merkel cell carcinoma. MicroRNAs are short, non-coding RNA (ribonucleic acid) molecules, capable of regulating gene expression at a post transcriptional level. They play a pivotal role in a variety of physiologic cellular functions and pathologies, including malignant diseases. The development of miRNAs represents an important study field, which has been extensively exploited in melanoma for almost a decade with promising results, therefore we consider it a stepstone for further research projects also in non-melanoma skin cancers. The aim of our study was to explore the current literature in order to present the role of the different miRNAs in some of the most frequent types of NMSC pertaining to oncogenesis, evolution and therapy. The most relevant and accurate available data from the literature were evaluated. Our study concluded that there are almost 100 miRNAs which can be upregulated or downregulated and can play a role in oncogenesis. They can be easily identified in circulation, are stable and they can be important diagnosis/prognosis and therapy monitoring markers.

Polymer-Based Bone Substitutes in Periodontal Infrabony Defects: A Systematic Evaluation of Clinical Studies.

Background and Objectives: The aim was to systematically review the available literature regarding the use of polymers as a bone substitute for the treatment of periodontal infrabony defect. Materials and methods: Three databases (PubMed, Scopus and Web of Science) were searched to find all relevant studies published in English from inception until September 2021 using a combination of keywords. The inclusion criteria consisted of human clinical studies which reported the use of a polymer-based bone substitute in the treatment of infrabony defects. Results: 164 studies were provided from the databases. Of these, five articles were eligible and reported favorable outcome in terms of probing depth, clinical attachment gain and defect fill at the follow-up (3 months and 6 months). Conclusions: Polymer based-bone substitutes may represent a useful alternative in treating infrabony defects. Due to the limited number of studies, more research is needed to sustain the advantages of these products.

Evaluation of Prognostic Factors for Palatal Fistulae after Cleft Lip and Palate Surgery in a North-Western Romanian Population over a 10-Year Period.

Cleft lip and palate is the most frequent birth anomaly, with increasing reported rates of complications, such as palate fistulae. Current studies concerning the occurrence rate of cleft lip and palate (CLP) report 2 to 10 cases in 10,000 births. The purpose of this study was to investigate the existence of factors that could predict the occurrence of fistulae after cleft lip and palate surgery. A retrospective study was performed by collecting and analyzing data from all patients who were operated for cleft lip and/or palate in the Maxillo-Facial Department of the Emergency Clinical County Hospital of Cluj-Napoca, Romania, between 2010 and 2020. We investigated the existing evidence for possible links between the number of fistulae observed after the primary palatoplasty and the age at which the primary palatoplasty was performed, the sex of the patient, the type of cleft, the timing of the surgical corrections, and the presence of comorbidities. A total of 137 cases were included for analysis. A significant link between the number of fistulae and the type of cleft was found (with fistulae occurring more frequently after the surgical correction of CLP-p < 0.001). No evidence was found for the existence of significant links between the number of fistulae and the patient's sex, the timing of surgery, or the presence of comorbidities. This study concluded that the incidence of palatal fistulae appears to be influenced by the type of cleft (CLP), but not by the sex of the patient, the timing of surgery, or the presence of comorbidities.

Assessing SARS-CoV-2 Infection Rate among Romanian Dental Practitioners.

Due to the impact of the Covid-19 pandemic on dental treatments, the present research aimed to assess the infection rate among dental practitioners from Romania and to analyze the economic impact of Covid-19 on dental offices. We designed a web-based survey distributed to dental practitioners from Romania. The survey included questions that assessed demographic data from the dentists who completed the questionnaire, along with economic aspects and epidemiological aspects related to the impact of the COVID-19 pandemic on dental practitioners. Five hundred and seven dentists completed the survey. Three-quarters of the assessed dental offices reported a decrease in the income and patient volume compared to 2019. More than half of the patients visiting the dental office paid more attention to the risk of infection and to prevention methods. Most dental offices implemented specific protective equipment for doctors. Three thousand seven hundred thirty-five dental practitioners were working in the 507 assessed dental offices, and among them, 238 COVID-19 cases of contamination were recorded. High contamination rates were registered in October (48, 20.1%), November (66, 27.7%), and December 2020 (52, 21.85%). Contamination mostly took place at home (114 cases, 47.8%) or resulted from event attendance. This study underlines an overall greater level of safety and an increased patient addressability in dental offices.

Engaging a polylactide copolymer in oral tissue regeneration: first validation of Suprathel® for guided epithelial and osseous healing.

The present study investigated the capacity of Suprathel® (a copolymer membrane, so far validated for skin regeneration) to also regenerate oral tissue - mucosa and bone, by comparing this biomaterial, in a split-mouth rabbit model, to Mucoderm®, a xenogeneic collagen matrix certified for keratinized oral mucosa healing. The clinical reason behind this experimental animal model was to determine whether the benefits of this advanced skin regeneration product (Suprathel®) could be conveyed for future evaluation in clinical trials of oral tissue regeneration in humans. The outcomes of this study validated the use of Suprathel®, a terpolymer of polylactide with trimethylene carbonate and ε-caprolactone, for stimulation of oral epithelium and alveolar bone regeneration in rabbits. Both Suprathel® and Mucoderm® exhibited comparable results and the null hypothesis stating a comparable regenerating effect of these two materials could not be rejected.

An Orthodontic Approach for Garre's Sclerosing Osteomyelitis of the Mandible.

The nonsuppurative osteomyelitis of the mandible is a rare condition that can occur in children due to low-grade inflammatory processes, dental cavities, periodontal lesions as well as the eruption process of the teeth. We submit a case report involving the orthodontic management of a 9-year-old female patient who presented in our service in the mixed dentition period with diagnosed Garre's sclerosing osteomyelitis of the entire mandibular body. After a full work-up, the following symptoms and signs were noted: bilateral temporomandibular joint (TMJ) pain, loss of the leeway space, anterior open bite, distalization of the secondary maxillary right canine, nail biting and tongue thrust. Our orthodontic objectives were to relieve the TMJ pain, limit the eruption process of the teeth and to diminish the evolution of the osteomyelitis, reduce the growth of the inferior lower third of the face and to prevent further invasive treatment of the patient. In the first phase of treatment, we established a centric relationship using an orthopedic appliance (occlusal splint) and physiotherapy to deprogram the muscles and the TMJ. Throughout the second phase of treatment, we used orthopedic appliances to inhibit the overeruption of the secondary molars. After another year of treatment, the osteomyelitis lesions were under control with the permanent teeth in final position, good facial esthetic and as a functional result, no root resorption. We can conclude that by using low physiological forces to direct and control the growth pattern, good results could be obtained in stabilizing and controlling the sclerosing osteomyelitis of the mandible.

Ligature induced periodontitis causes atherosclerosis in rat descending aorta: an experimental study.

INTRODUCTION: In recent years a link between periodontitis and cardiovascular diseases has been proposed. Oxidative stress has been found to be involved in their pathophysiology. OBJECTIVES: The aim of this study was to demonstrate that a wire ligature placed around the first mandibular molars of the rat causes inflammation in the periodontium and lipid deposits in the aorta, via oxidative stress. METHODS: Twenty male Wistar rats were divided randomly into two groups of 10: Control group and Periodontitis group. An orthodontic wire ligature was placed around the cervix of the first mandibular molar and was kept in place for 4 weeks. Clinical attachment loss was determined to assess the gingival recession. Aorta was harvested after 4 weeks and the malondialdehyde (MDA) levels in the aorta tissue homogenate were determined. Lipid deposits were evaluated using Oil Red staining and immunofluorescence under confocal microscopy. Total lipid deposits in the aorta were assessed using a computer morphometry system. RESULTS: Significant gingival recession was observed in the Periodontitis group in comparison with the Control group. Increased MDA levels were present in the aorta in the ligatured rats in comparison with the Control group. Significant lipid deposits were observed in the aorta of the Periodontitis group as opposed to the Control group. CONCLUSIONS: The affixing of an orthodontic wire ligature produces gingival recession, increased oxidative stress and lipid deposits in the rat descending aorta.

Cross-sectional imaging and cytologic investigations in the preoperative diagnosis of parotid gland tumors - An updated literature review.

An accurate preoperative diagnosis of parotid tumors is essential for the selection and planning of surgical treatment. Various modern cross-sectional imaging and cytologic investigations can support the differential diagnosis of parotid tumors. The aim of this study was to achieve a comprehensive and updated review of modern imaging and cytologic investigations used in parotid tumor diagnosis, based on the latest literature data. This literature review could serve as a guide for clinicians in selecting different types of investigations for the preoperative differential diagnosis of parotid tumors. Magnetic resonance imaging (MRI) with its dynamic and advanced sequences is the first-line imaging investigation used in differentiating parotid tumors. Computed tomography (CT) and positron emission tomography (PET)-CT provide limited indications in differentiating parotid tumors. Fine needle aspiration biopsy and core needle biopsy can contribute with satisfactory results to the cytological diagnosis of parotid tumors. Dynamic MRI with its dynamic contrast-enhanced and diffusion-weighted sequences provides the best accuracy for the preoperative differential diagnosis of parotid tumors. CT allows the best evaluation of bone invasion, being useful when MRI cannot be performed, and PET-CT has value in the follow-up of cancer patients. The dual cytological and imaging approach is the safest method for an accurate differential diagnosis of parotid tumors.

The Influence of Eggshell on Bone Regeneration in Preclinical In Vivo Studies.

The aim of this study is to systemically review the available evidence on the in vivo behavior of eggshell as a guided bone regeneration substitute material. Five databases (PubMed, Cochrane, Web of Science, Scopus, EMBASE) were searched up to October 2020. In vivo animal studies with a bone defect model using eggshell as a grafting material were included. Risk of bias was assessed using SYRCLE tool and the quality assessment using the ARRIVE guidelines. Overall, a total of 581 studies were included in the study, 187 after duplicate removal. Using the inclusion and exclusion criteria 167 records were further excluded. The full text of the remaining 20 articles was assessed for eligibility and included in the qualitative and quantitative assessment synthesis. There were different methods of obtaining eggshell grafting materials. Eggshell is a biocompatible grafting material, with osteoconduction proprieties. It forms new bone similar to Bio-Oss and demineralized freeze-dried bone matrix. It can be combined with other materials to enhance its proprieties. Due to the high variability of the procedures, animals, production and assessment methods, no meta-analysis could be performed. Eggshell might be considered a promising biomaterial to be used in bone grafting procedures, though further research is needed.