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Comparative analysis of the fracture resistance of a polymeric material for 3D printing and a milled polymethylmethacrylate material as interim material for fixed partial dentures: new material updated
(Universidad de Cuenca, 2023-12-12) Córdova Díaz, Johanna Mireya; Merchán Cabrera, Andrea Isabel; Abad Coronel, Cristian Gustavo
Abstract: The aim of this study was to evaluate and compare the fracture resistance of a temporary three-unit fixed dental prosthesis (FDP) made of a new polymeric material obtained by an additive technique (3DPP) using a computer-aided design and manufacturing (CAD/CAM) system, comparing the prosthesis to the respective outcomes of temporary polymethylmethacrylate (PMMA) FDPs obtained by a subtractive technique (milling). Methods: Three-unit FDPs were 3D printed using a polymeric material (n = 20) or milled using polymethylmethacrylate (n = 20). After thermocycling at 5000 cycles at extreme temperatures of 5 ◦C and 55 ◦C in distilled water, each specimen was subjected to a compression test on a universal testing machine at a rate of 0.5 mm/min until failure occurred, recording the value in newtons (N). Results: There were statistically significant differences (p-value < 0.005) between the PMMA material (2104.7 N; SD = 178.97 N) and 3DPP (1000.8 N; SD = 196.4 N). Conclusions: The fracture resistance of the PDFs manufactured from milled PMMA showed higher values for fracture resistance. However, the resistance of the 3DPP showed acceptable values under mechanical load; this notable advance in the resistance of printed materials consolidates them as an important alternative to use in interim indirect restorations.
Digitalización aplicada en prótesis dental: revisión sistemática de la literatura”
(2019-05-10) Valdiviezo Zhunio, Claudia Pamela; Abad Coronel, Cristian Gustavo
CAD / CAM systems is the acronym of computer aided design / computer aided manufacturing, whose translation into Spanish means computer-aided design / computer-aided manufacturing, was introduced in dentistry with the aim of automating production and standardizing the quality of dental restorations; Intraoral scanners began to be used in the field of prosthodontics in the early 1980s through the concept of intraoral digital impressions. This got the integral attention of the dentists and has been used for the manufacture of dental prostheses in several cases. It is expected that the use of these scanners in the digital printing technique will generate an absolute digitalization in prosthodontics. Furthermore, some published articles have indicated that dental prostheses made from intraoral digital impressions have shown remarkable advantages over conventional impressions in several aspects. Methodology: This systematic review used the PRISMA (Preferred Reporting Items of Systematic reviews and Meta-analysis) guide to ensure the quality of the information included. To do this, the checklist of items included in said guide was handled. The PICO system was also used. Conclusions: the optical impressions reduce the patient's discomfort; they are efficient over time and simplify clinical procedures, allow better communication with the dental technician and with patients; however, with IOS, it can be difficult to detect deep margin lines on prepared teeth or in case of gingival bleeding.
Fracture resistance analysis of CAD/CAM interim fixed prosthodontic materials: pmma, graphene, acetal resin and polysulfone
(Universidad de Cuenca, 2023-12-11) Calle Barros, Marcia Carolina; Abril Ochoa, Diana Gabriela; Abad Coronel, Cristian Gustavo
The aim of this study was to evaluate and compare the fracture resistance of temporary restorations made of polymethylmethacrylate (PMMA), graphene-modified PMMA (GRA), acetal resin (AR) and polysulfone (PS) obtained by a subtractive technique (milling) using a computer- aided design and manufacturing (CAD/CAM) system of a three-unit fixed dental prosthesis (FDP). Meth- ods: Four groups of ten samples were fabricated for each material. Each specimen was characterized by a compression test on a universal testing machine, all specimens were loaded to fracture and the value in Newtons (N) was recorded by software connected to the testing machine. The fracture mode was evaluated on all samples using a stereomicroscope. Results: There were statistically significant differences (p value < 0.005) between PMMA and the other three materials (PMMA: 1302.71 N; GRA:1990.02 N; RA: 1796.20 N; PS: 2234.97). PMMA presented a significantly lower value than the other materials, and PS showed the highest value. GRA and RA presented a similar range of values but they were still higher than those of PMMA. Conclusions: GRA, RA and PS are presented as valid options within the range of interim milled restorative materials and as alternatives to PMMA.
Lesiones Cervicales No Cariosas: Revisión sistemática de la literatura
(2019-06-07) Torres Robles, Allysson Abigail; Abad Coronel, Cristian Gustavo
Non - carious cervical lesions (LCNC) are very frequent in clinical practice, referring to the loss of hard tissue located in the amelo - cemental limit; Its etiology is multifactorial, intervening factors such as: alteration in dental occlusion, chemical agents, mechanical forces not appropriate, among others. It is presented in varied morphology, with sensitivity or without it, the dental pulp reaching a compromise. Hunter classifies the LCNC in: abrasion, erosion, attrition and abfraction, as a cause of confusion to date because of its origin and location. The scientific evidence gives us different contributions of these injuries that are known in the development of this research. Methodology: a review of the available literature was carried out using the PubMed and Cochrane database in our studies in English and Spanish reported from 2014 to 2019; POOL (Preferred report elements of systematic reviews and meta-analyzes) ensuring the quality of the information. Conclusion: LCNC present varied etiology, requires the interaction of several factors for its development. It was observed more frequently in adult patients (80%) whose prevalence increases with age. According to the morphology, the LCNC presents a wedge and saucer shape on the vestibular surfaces of the maxillary teeth. Taking into account all these points, the professional dentist must have knowledge of each of these injuries to make a correct diagnosis and apply the appropriate treatment to each of them.
Materiales y sistemas cerámicos actuales utilizados en próstesis fija: revisión sistemática de la literatura
(2013) Delgado Gaete, Bolívar Andrés; Abad Coronel, Cristian Gustavo
Objective: This Project aims to conduct a systematic review of the current literature covering the ceramic materials and systems used in fixed prostheses with respect to survival, material properties, marginal and internal fit to offer recommendations and clinical guidelines for use based on scientific evidence. Method and materials. A comprehensive literature review was completed between October 2012 to December 2012 with research that provided evidence regarding treatment of teeth with ceramic materials and systems. The search was performed using digital databases MEDLINE, PubMed and Cochrane; articles in English with a focus on evidence published between 2000 and 2012 were included. Search filters were used to limit the review, literature reviews and randomized controlled studies were included in this systematic review. All data to support or criticize the clinical application of ceramic materials and systems in terms of their survival, material properties, and marginal fit were investigated. Based on the results of this research, a guide of clinical recommendation was elaborated for the selection and application of current ceramic materials
Preparaciones dentarias en prótesis fija dentosoportada: revisión sistemática
(2013) Gil Pozo, Jenny Alexandra; Abad Coronel, Cristian Gustavo
The principles of tooth preparation are commonly as: biological, biomechanical an aesthetic. Biological factors are influencing the health of periodontal tissues and pulp, the biomechanical (or technical) will affect the integrity and durability of the restorations, and aesthetic factors are related to the natural appearance of the restorations. These principles are routinely modified to suit various clinical situations. Proper tooth preparation intended to prosthodontics treatment should allow successful reproduction of anatomical contours and emergence profiles. Besides providing an appropiate thickness for each type of structure, without exceeding the limitations of each material as well as maintain the biological integrity of the related tissues
Restauraciones provisionales en prótesis fija: revisión sistemática
(2013) Astudillo Rubio, Daniela Andrea; Abad Coronel, Cristian Gustavo
A systematic review of the literature was conducted through a search in digital databases on updates about the different materials used in the manufacture of provisional restorations. The comprehensive review of the literature was conducted in the period from March 2012 to March 2013, to provide contemporary scientific guidance on the subject. Reference publications were used as scientific articles, clinical and in vitro studies were found to carry out searches in Medline and Cochrane, articles published from 1970 to the present. The articles included in this review, involving topics on mechanical properties, marginal adaptation, gingival and pulpal response and color stability of different materials used in the interim treatment, which shall guide the clinical selection and processing techniques. Specific names of products and manufacturers are included in this report only when the original publications cited in the reference
Sistemas adhesivos utilizados en la cementación de restauraciones indirectas: Revisión Sistemática de la Literatura
(2019-04-04) Naranjo Yépez, Maríx Belén; Abad Coronel, Cristian Gustavo
Objective: To carry out a systematic review of the adhesive systems, used in the cementation of indirect restorations based on the available scientific evidence, based on the bonding strength of these to the dental tissues. Materials and methods: A literature review was made available in two digital databases, Pubmed and Cochrane, where relevant studies dealing with adhesive systems were identified, associated with clinical behavior and strength of attachment to dental tissues. The search included articles in English, carried out in vitro, published between 2012 and 2018. This systematic review used the PRISMA, guide to ensure the quality of the information included. For this, the checklist of items included in said guide was handled. The PICO System, was also included. Results: Finally, 12 articles were selected, studies with different designs and the lack of standardization of samples and protocols was a common denominator. However, it could be determined that there was greater bond strength in the three-step adhesive systems and self-etching systems + a previous selective etching. It was not possible to perform a summation of the adhesion strength since the studies were not performed with standardized samples, both in the size of the sample and in the materials used to obtain the results. Conclusions: The heterogeneity of the studies made it difficult to establish a consensus on the best conditions of application of the adhesive systems, however, most of the studies to assess the bond strength use microtensile traction techniques and shear strength. It was determined that the three-step systems achieve the highest values of adhesion strength independently of the evaluation method used and the clinical use. These systems form a true hybrid layer with the substrate, while the simplified systems reach lower bonding values, and form superficial hybrid layers, more prone to degradation

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Browsing Especializaciones by Author "Abad Coronel, Cristian Gustavo"