Design and fabrication of human skin by threedimensional bioprinti

Skin has an essential role in preserving homeostasis and in maintaining the safety of the human body from outside environment by playing its role as the largest body part of human. The stratified, categorized and complex arrangement of skin gives a physical protection to the body by maintaining and regulate the transportation of metabolites and water off the body. The injuries that can originate after any chemical or physical trauma can cause impairment of skin barrier and its physiological functions.1 In skin injuries, considerable amount of skin can be lost, and it develops extremely critical to replace injury caused impaired skin. Transplants in order to protect the lots of water from body and to save the body from opportunistic pathogens can replace the impaired skin. Skin grafts can also expedite the wound recovery procedure and support and restore the barrier and can maintain the regulatory functions on the site of wound.2,3 Apart from grafts tissue engineered skin plays an exceptionally beneficial role and in vitro stage for the evaluation of skin permeability and adverse inflammation response. The tissue-engineered skin has several advantages in comparison to animal skin by having the major significance by mimicking the skin physiology and easing the ethical concerns of animal use. Additionally, tissue engineered skin models also give the significant insights into the causes of skin diseases, hence, explicate the pathophysiological mechanisms in order to see the progression, and can help in the treatment of skin disease.4,5 It has been seen that numerous tools have become accessible for the tissue engineering and are adopting different novel approaches and technologies, and amongst these 3D bioprinting offers many significant advantages Since it is possible of dispensing live cells, phase changing hydrogels, insoluble factors and maintaining high cell viability in a desired pattern.6

Evaluation of periodontal condition in individuals with down syndrome: a case-control study

Ogival palate, macroglossia, anodontia, cleft tongue, delayed tooth eruption, low prevalence of caries and high prevalence of periodontal disease are the main oral manifestations of Down syndrome. The aim of the present observational study was to evaluate the periodontal condition in individuals with Down syndrome. The study included 30 individuals who were selected according to the age group to be studied, between 17 and 25 years old, in a local institution for the care of Down syndrome (DG) patients and 30 individuals who made up the control group and who did not have Down syndrome (CG), periodontal parameters were observed in both groups that were adjusted for habits. The results showed for the Plaque Index 41.2% of the individuals in the DS group while in the CG group in 45.5% without statistical difference. For the Gingival Index, it was observed that 39.7% in the DS group and in the CG group 44.2% without statistical difference between the groups (p <0.05). Family and institutional participation collaborates in the daily control of dental biofilm. In the present study, individuals in the DG group presented periodontal clinical parameters compatible with periodontal health and when compared to healthy individuals, they did not present clinical differences.

A review on the effect of using rotary hyflex electrical discharge machining endodontic files on the formation of dentinal microcracks in straight root canals

Endodontic therapy is based on cleaning and shaping the canal system till the apex with total obturation of the canal. However, it is not always straightforward. Endodontics specialists face many complicated cases as sever curved canals, calcified canals and canals with previously initiated therapy which require to deal with. dental professionals pay attention to create new methods or to improve the already developed equipment and procedures to facilitate their work. Rotary endodontics files are in the center of attention. nowadays, recent files with extraordinary properties have been revolutionized. The standard Nickel Titanium rotary endodontic files are not always preferred. It cannot serve well in the aforementioned complex cases due to its larger tapers and unique shape memory property. Moreover, these files have led to several dentinal microcracks formation during canal preparation using the flaring instruments. Microcracks are evaluated through the accurately presented sliced images using Micro-Computer Tomography (micro-CT) done before and after root canal preparation. This has led to the invention of new generations of rotary endodontics files, with unique properties improving its behavior during the instrumentation, including Controlled Memory (CM) files and Electrical discharge Machine (EDM) files, opening the door for a new era in the field of endodontics dentistry. The present study aims to review HyFlex EDM files, including their properties, clinical dental usage, and the role of micro-CT in analyzing dentinal micro cracks formed with HyFlex EDM files.

Psychological affectation in child maloclutions

In recent years, different investigations have highlighted the importance of constructing the diagnosis based on complexity in health, which implies putting the concept of comprehensive dental health in perspective. Occlusal alterations in childhood have a multifactorial etiology, considering the dental, muscular and skeletal factors of the stomatognathic complex as well as the subject in their psychism and social environment, noting the maturational development of the child, therefore this article presents an update on the affectation Psychology in child malocclusions and the impact they cause in the construction of the childhood personality.

Ankylosis of the Temporomandibular Joint (TMJ) Update and its treatment

In dentistry, temporomandibular joint (TMJ) ankylosis is a rare pathology where no consensus of global population data has been found and therefore has presented a challenge for professionals, since there are no treatment sequence protocols standardized. The objective is to carry out a literature review and update of the diagnosis of ankylosis, considering its clinical characteristics, classification, etiology, and epidemiology. Giving special emphasis to the types of treatments used and concluding that GAP interpositional arthroplasty and TMJ reconstruction arthroplasty would be the best options to improve maximum oral opening in a patient with ankylosis, thus allowing him to recover function and aesthetics.

Evaluation of bond strength in lithium disilicate ceramics subjected to different times and methods of removal of hydrofluoric acid residues

Objective: To evaluate the bond strength in lithium disilicate ceramics subjected to different times and methods of removal of conditioning residues. Materials and methods: Bonding strength was evaluated in lithium disilicate discs after conditioning with hydrofluoric acid, the samples were subjected to different times and methods of removal: air-water spray, ultrasonic bath with distilled water 2 min, ultrasonic bath with distilled water 4 min, phosphoric acid 2 min, phosphoric acid 4 min. Cylinders were made of flowable composite resin that were positioned on the discs. The samples were subjected to micro-shear tests on a universal testing machine. Results: The two-way ANOVA test and the Pos Hoc Tukey test (p<0.05) revealed that the ultrasonic bath group with distilled water 2 min presented significant difference with respect to the phosphoric acid 4 min; however, it did not present significant difference with respect to the other groups. Conclusion: The ultrasonic bath removal method for 2 min presented the highest value of bonding strength.

Esthetic ceramic veneers for spaced anterior teeth utilizing the RED proportion; a case report with three years follow-up

Discrepancy between a large jaw size and small teeth results in a spaced alignment of teeth. Orthodontic treatment to correct such cases will not be sufficient for esthetic results of anterior teeth. Restorative treatment may be the ideal solution to reshape small teeth in well planned proportion to fit the size of the jaw and enhance the appearance of the patient smile. This paper presents the process of restoring spaced anterior teeth with minimally prepared ceramic veneers using the RED proportion.

Restoring a fractured incisor of a teenager with partial veneer

Since trauma is a common incident that adolescents are faced with, the post-traumatic therapeutic solution presents a challenge for the clinicians .This case report demonstrates how a young patient with minimal extended fracture of incisor was rehabilitated with non-invasive adhesive restoration known as partial veneer or chip with Feld spathic porcelain. Those restorations fit into the anatomy and shape of the teeth perfectly and restore only the fractured part which integrates in tissue economy dynamic. Feldspathic porcelain is the material that best reproduces the characteristics of enamel, in terms of surface properties, modulus of elasticity, resistance to fracture and the reproduction of the optical properties of the dental structure, especially at minimal thickness. In this paper we describe the details of the treatment and the final result which was aesthetic and surpass the patient’s expectation.

Knowledge and ability assessment of endodontists to prescribe and analyze cone beam computed tomography

Objective: To determine the prevalence of knowledge about cone-beam computed tomography (CBCT) by endodontists from the Metropolitan Area of Belém, Pará, Brazil. Material and methods: 151 questionnaires were spread containing 32 questions, 15 closed questions, 4 open and 13 mixed. Questions 1 to17 dealt with questions such as age; gender; geographic location where endodontists' office operates; year of graduation degree and of specialization in endodontics; owned equipment and questions about the conventional radiology practice at dental office. Questions 18 to 32 were related to knowledge about the CBCT and only those who reported having knowledge answered the questions 19 onwards. Results: 81 questionnaires were analyzed. 48 endodontists (59%) had some knowledge about CBCT, but among them, 5 never requested until that occasion. Regarding the radiation level, 76.75% have not any information about. The treatment plan of 36 (83.72%) those who requested CBCT changed. Conclusion: The CBCT imaging is slowly becoming an essential modality of imaging in the clinical practice of endodontists from the Metropolitan Area of Belém, Para, Brazil.

Clinical evaluation of growth potentiality of autogenous costochondral graft in Temporomandibular joint on New Zealand white rabbit- an experimental study

Background: Costochondral graft has been used as a substitute for a growth center in the damaged Temporomandibular joint (TMJ) in the growing children. But the relapse of the TMJ ankylosis along with facial deformity is the most common outcome after the surgery for the resorption or overgrowth of the graft. While an exploration of the human Temporomandibular joint seems to be unethical after reconstruction with an autogenous costochondral graft for study purposes, therefore we sought to determine the growth potential of the graft by clinical evaluation. Material and methods: An experimental study was done on 96 New Zealand white male rabbits, which were divided into batches. Each batch (total 2 batches) contained 24 experimental and 24 control rabbits of known ages and species; growing (3-4) and adult (12-18) months old. TMJ arthroplasty with a costochondral graft using either 1mm or 4 mm thickness of cartilaginous cap done in both age groups. Follow-up was done regularly in batches comparing with control up to 4th, 12th, and 24th weeks of surgery to find out any relationship of behavioral change, clinical presentation, and macroscopic growth of the graft. Results: There was a relationship among the rabbits with their behavioral change, clinical presentation, and presence of growth center in the graft. Growth was found in 60% cases, 40% was growing, and 20% in adults. Conclusions: Costochondral graft had a 60% growth potentiality. The failure rate of 40% may be due to some unknown factors. Grafts grew in a greater number of growing rabbits than adults. Long time follow-up had a strong role in the growth of the graft. In conclusion, clinical evaluation of the rabbit model provided a fair estimation of the growth process.