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The study of the maxillary sinus anatomy should consider the presence of two features of clinical importance. The arterial supply course and the presence of the so-called Underwood septa are two important factors to consider when planning surgical treatment to reduce the risk of surgical complications such as excessive bleeding and Schneiderian membrane perforations. This study aimed to investigate the above-mentioned anatomical structures to improve the management of eventual vascular and surgical complications in this area. This study included a total of 200 cone-beam computed topographies (CBCTs) divided into two groups of 100 CBCTs to evaluate the arterial supply (AAa) course through the lateral sinus wall and Underwood's septa, respectively. The main parameters considered on 3D imaging were the presence of the AAa in the antral wall, the length of the arterial pathway, the height of the maxillary bone crest, the branch sizes of the artery in the first group, and the position of the septa, the length of the septa, and their gender associations in the second group. The CBCT analysis showed the presence of the arterial supply through the bone wall in 100% of the examined patients, with an average size of 1.07 mm. With regard to the septa, 19% of patients presented variations, and no gender difference was found to be statistically significant. The findings add to the current understanding of the clinical structure of the maxillary sinus, equipping medical professionals with vital details for surgical preparation and prevention of possible complications.
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Tomografía Computarizada de Haz Cónico , Imagenología Tridimensional , Seno Maxilar , Humanos , Seno Maxilar/diagnóstico por imagen , Seno Maxilar/irrigación sanguínea , Tomografía Computarizada de Haz Cónico/métodos , Femenino , Masculino , Imagenología Tridimensional/métodos , Persona de Mediana Edad , Adulto , Anciano , Adulto JovenRESUMEN
Plasmacytoma is a neoplastic disorder originating from plasma cells, with bone and soft tissue being common sites of manifestation. This report presents the clinical and radiological findings of a 65-year-old female patient who presented with an exophytic lesion in the upper right lateral incisor region. The lesion appeared as a unilocular radiotransparent area in imaging tests. Following an excisional biopsy, histological and immunohistochemical evaluations confirmed the presence of mature plasmacellular elements and small infiltrates of B and T lymphocytes. The patient did not exhibit systemic manifestations of multiple myeloma. Surgical intervention, in the form of enucleation of the lesion combined with root canal treatment and apicoectomy, was performed. This case underscores the rare occurrence of plasmacytoma in the jaw region and highlights the importance of surgical management in cases where structural damage or functional impairment is present. Further research on novel treatment approaches is also mentioned, including targeted therapies, immunomodulatory agents, and monoclonal antibodies. The patient is currently under the care of a hematologist for further investigation and the choice of the most appropriate therapy.
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The purpose of this observational study is to evaluate the prevalence and main characteristics of bifid canals within a European adult population, analyzing cone-beam-computed tomography (CBCT). The population study examined 300 subjects. The CBCTs were performed between 2012 and 2019, using PaX-Zenith3D with a standard protocol of acquisition. The parameters analyzed were the presence and lengths of the bifid mandibular canals. The sample included 49% male and 51% female participants. The mean age of the patients was 47.07 ± 17.7 years. Anatomical variants of the mandibular canal were identified in 28.8% of the sides and 50.3% of the patients. In 7.3% of the subjects, the anatomical variants were present bilaterally. The most frequently encountered bifid canal was Type 3 (40.5%), followed by the Type 1 canal (39.3%), the Type 2 canal (14.5%), and the Type 4 canal (5.9%), 40% on the right side and 60% on the left side. The average length of the bifid canals located on the right side of the mandible was 11.96 ± 5.57 mm, compared to 11.38 ± 4.89 mm for those measured on the left side. The bifid mandibular canal is a common anatomical variation of the mandibular canal. It is fundamental to performing an accurate preoperative evaluation using CBCT analysis to avoid and/or reduce intraoperative and postoperative complications.
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Several types of deproteinised bovine bone mineral (DBBM) are available on the market, and each one is obtained with a thermic and chemical process that can differ, achieving different results. Currently, several protocols using low temperature are suggested to reduce the possible particle crystallisation during the production process. This study aimed to evaluate the biomorphological reaction of periodontal fibroblast cultures in contact with different DBBM particles treated with a low-temperature protocol (Thermagen®) and without exposure to sodium hydroxide (NaOH). Morphological evaluation was performed using light, confocal laser, and scanning electron microscopy, and the biological reaction in terms of proliferation was performed using an XTT proliferation assay at 24 h (T1), 72 h (T2), and 7 days (T3). The morphological analysis highlighted how the presence of the materials stimulated a change in the morphology of the cells into a polygonal shape, surface reactions with the thickening of the membrane, and expression of actin. In particular, the morphological changes were appreciable from T1, with a progressive increase in the considered morphological characteristics at T2 and T3 follow-ups. The proliferation assay showed a statistical significance between the different experimental materials and the negative control in T2 and T3 follow-ups. The post hoc analysis did not reveal any differences between the materials. In conclusion, the grafts obtained with the low-temperature extractions protocol and not exposed to NaOH solution showed positive morphological reactions with no differences in the sizes of particles.
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Fibroblastos , Ligamento Periodontal , Animales , Bovinos , Células Cultivadas , Fibroblastos/metabolismo , Humanos , Minerales/metabolismo , Hidróxido de Sodio , TemperaturaRESUMEN
Platelets are a cellular subgroup of elements circulating in the bloodstream, responsible for the innate immunity and repairing processes. The diseases affecting this cellular population, depending on the degree, can vary from mild to severe conditions, which have to be taken into consideration in cases of minor dental procedures. Their secretion of growth factors made them useful in the regenerative intervention. The aim of this review is to examine the platelets from biological, examining the biogenesis of the platelets and the biological role in the inflammatory and reparative processes and clinical point of view, through the platelets' pathology and their use as platelets concentrates in dental regenerative surgery.
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Understanding the biological and morphological reactions of human cells towards different dentinal derivate grafting materials is fundamental for choosing the type of dentin for specific clinical situations. This study aimed to evaluate human periodontal ligament fibroblasts (hPLF) cells exposed to different dentinal derivates particles. The study design included the in vitro evaluation of mineralized dentine (SG), deproteinized and demineralized dentine (DDP), and demineralized dentine (TT) as test materials and of deproteinized bovine bone (BIOS) as the positive control material. The materials were kept with the hPLF cell line, and the evaluations were made after 24 h, 72 h, and 7 days of in vitro culture. The evaluated outcomes were proliferation by using XTT assays, the morphological characteristics by light microscopy (LM) and by the use of scanning electron microscopy (SEM), and adhesion by using confocal microscopy (CLSM). Overall, the experimental materials induced a positive response of the hPLFs in terms of proliferation and adhesion. The XTT assay showed the TT, and the SG induced significant growth compared to the negative control at 7 days follow-up. The morphological data supported the XTT assay: the LM observations showed the presence of densely packed cells with a modified shape; the SEM observations allowed the assessment of how fibroblasts exposed to DDP and TT presented cytoplasmatic extensions; and SG and BIOS also presented the thickening of the cellular membrane. The CLMS observations showed the expression of the proliferative marker, as well as and the expression of cytoskeletal elements involved in the adhesion process. In particular, the vinculin and integrin signals were stronger at 72 h, while the actin signal remained constantly expressed in all the follow-up of the sample exposed to SG material. The integrin signal was stronger at 72 h, and the vinculin and actin signals were stronger at 7 days follow-up in the sample exposed to DDP material. The vinculin and integrin signals were stronger at 72 h follow-up in the sample exposed to TT material; vinculin and integrin signals appear stronger at 24 h follow-up in the sample exposed to BIOS material. These data confirmed how dentinal derivates present satisfying biocompatibility and high conductivity and inductivity properties fundamental in the regenerative processes. Furthermore, the knowledge of the effects of the dentin's degree of mineralization on cellular behavior will help clinicians choose the type of dentine derivates material according to the required clinical situation.
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Biomarcadores/metabolismo , Sustitutos de Huesos/farmacología , Dentina/química , Ligamento Periodontal/citología , Animales , Sustitutos de Huesos/química , Bovinos , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Fibroblastos/citología , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Humanos , Integrinas/metabolismo , Ensayo de Materiales , Microscopía Confocal , Microscopía Electrónica de Rastreo , Ligamento Periodontal/efectos de los fármacos , Ligamento Periodontal/metabolismo , Vinculina/metabolismoRESUMEN
The aim of this study was to analyse the influence of different thread shapes of titanium dental implant on the bone collagen fibre orientation (BCFO) around loaded implants. Twenty titanium dental implants, divided for thread shapes in six groups (A-F) were analysed in the present study. All implants were immediately loaded and left in function for 6 months before retrieval. The parameters evaluated under scanning electron microscope were the thread width, thread depth, top radius of curvature, flank angle, and the inter-thread straight section. Two undecalcified histological sections were prepared from each implant. Birefringence analysis using circularly polarized light microscopy was used to quantitively measure BCFO. For groups A-F, respectively, transverse BCFO was 32.7%, 24.1%, 22.3%, 18.2%, 32.4%, and 21.2%, longitudinal BCFO was 28.2%, 14.5%, 44.9%, 33.1%, 37.7%, and 40.2%. The percentage differences between transverse and longitudinal orientation were 4.50% (A), 9.60% (B), -22.60% (C), -14.90% (D), -5.30% (E), and -19.00% (F). Following loading, the amount of transverse and longitudinal BCFO were significantly influenced by the thread shape. The greater flank angles and narrower inter-thread sections of the "V" shaped and "concave" shaped implant threads of groups A and B, respectively, promoted the predominance of transverse BCFO, compared to groups C-F (p < 0.05). A narrow inter-thread straight section promotes transverse BCFO, as do "V" shaped and "concave" shaped threads, which can thus be considered desirable design for implant threads.
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Implantes Dentales , Colágenos Fibrilares/fisiología , Maxilares/fisiología , Oseointegración , Diseño de Prótesis , Humanos , Maxilares/anatomía & histologíaRESUMEN
The COVID-19 pandemic literally stopped most human movement and activities as it initially spread, which included dental practices and dental education. This defined the need for significative changes in teaching and learning with the use of "e-learning" methods, also for traineeships. This study was designed to determine the undergraduate student perception of these new methods as part of their education. This involved 353 students attending the Dental School of the G. D'Annunzio University of Chieti-Pescara, from the first to the sixth years. A questionnaire in Italian and was set-up using "Google Forms" and sent by email to the students. The questionnaire was divided into three parts: the first part included questions for general information, including age, sex and year of course; the second part had multiple choice questions related to their evaluation of the e-learning teaching, using a scale of opinion in the replies to each question (e.g., "scarce", "fair", "satisfying", "very good" and "excellent"); and the third part included two open questions to indicate the strengths and limitations of these new teaching and learning approaches. The categorical variables in the first and second parts of the questionnaire were evaluated using Chi squared tests, setting significance at p < 0.05, while the comments were evaluated qualitatively. The student feedback showed significant appreciation (p < 0.05) of the new methods and the efforts that the lecturers put in to provide lectures of as high a quality as possible. However, a lack of practical training was significantly perceived as an important problem in the structure of their new curriculum (p < 0.05). COVID-19 has been an epic tragedy that has hit the human population not only in terms of health and healthcare, but also quality of life. This includes the quality of dental education within universities. However, the pandemic can be seen to also represent motivation to invest in the necessary technological innovation to deliver the best possible education to our future dentists.
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No abstract available.
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Persistent organic pollutants (POPs) constitute a relevant part of environmental pollution. POPs are chemical compounds that persist for a long time in the environment, bio-accumulate in the human body and determine significant adverse consequences to human health. The characteristics of these substances are lipo-affinity, semi-volatility and resistance to the degradation processes. Results deriving from several different studies attest that exposure to the main classes of POPs results in multiple toxic effects on humans and experimental animal models. Among the various alterations caused by exposition to and bio-accumulation of POPs, there are abnormalities in tooth formation and related hard dental tissue structure, especially enamel. This review aimed to describe the close association between the exposure of these compounds during the development of the tooth germ and the occurrence of tooth structural anomalies. Indeed, structural defects of the enamel have as possible consequences higher susceptibility of the tooth to caries disease and higher fragility of the crown to the occlusal trauma.
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Odontogénesis/efectos de los fármacos , Contaminantes Orgánicos Persistentes/efectos adversos , HumanosRESUMEN
Adhesive restorations have been shown to guarantee excellent performance and longevity, although this comes with some disadvantages. Among these, the vulnerability of dentine to different agents has been widely evaluated. The aim of this study was to evaluate the possible penetration of impression materials into freshly cut dentine. Dentine from 27 teeth was impressed with polyether (Impregum Penta L) (nine teeth) and with polyvinyl siloxane (Aquasil Ultra LV) (nine teeth). The surface of nine teeth after the impressions were used as the control. Specifically, the extroflections caused by the imprinting of the dentinal tubules on the impression material, the so-called impression tags, were measured. Furthermore, the presence of the material inside the tubules was examined. Scanning electron microscopy analysis showed material tags for all of the experimental groups. The mean lengths (±SD) were 22.6 (±11.0) µm for polyether, 21.8 (±12.8) µm for polyvinyl siloxane and 11.3 (±7.0) µm for the tooth control, with mean diameters (±SD) of 2.8 (±0.5), 2.4 (±0.7) and 3.1 (±0.7) µm, respectively. Fractal analysis showed fractal dimensions of 1.78 (±0.03), 1.77 (±0.03) and 1.71 (±0.03), respectively. These data demonstrated that the impression materials can remain inside the dentinal tubules, which can adversely affect the adhesive procedures.
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The loosening of an abutment screw is one of the most frequent complications in implant-prosthetic rehabilitation, especially for single-crown cemented prostheses. This complication is due to several mechanical factors including type of connection, abutment-screw geometry, settling effects, and cyclical load. The purpose of the present in vitro study was to compare and associate different times of retightening with reductions in preload losses. We evaluated 40 internal hexagon dental implants and 40 external hexagon dental implants, with their related abutment screws. The implants were embedded in acrylic resin in cylindrical polyvinyl chloride tubes (26 mm diameter, 20 mm height). The abutments were fixed to the implants with screws to an initial torque of 35 Ncm using a digital torque meter with decimal precision. Two different types of connection were randomly divided in 4 subgroups of 10 samples each. One subgroup was used as control. The test groups underwent retightening to the same initial torque at increasing times from initial torque application for tightening of the abutment screws, to their retightening at 2 minutes, 5 minutes, and 10 minutes. The retightening time of 2 minutes shows significantly reduced preload loss. Randomized clinical trials are strongly required to provide clinicians with a beneficial standardized protocol of retightening that can be applied in routine clinical practice.
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Implantes Dentales , Coronas , Pilares Dentales , Diseño de Implante Dental-Pilar , Análisis del Estrés Dental , TorqueRESUMEN
Bone defects repair represents a public and urgent problem in clinical practice, in fact, every year, more than two million patients required new treatments for bone injuries. Today a complete vascularization is strategic in bone formation, representing a new frontier for clinical application. Aim of this research has been developed a three-dimensional (3D) coculture platform using a bovine pericardium collagen membrane (BioR) loaded with human periodontal ligament stem cells (hPDLSCs) and endothelial differentiated cells from hPDLSCs (E-hPDLSCs) able to undergo toward osteoangiogenesis differentiation process. First, we have characterized at confocal laser scanning microscopy (CLSM) level the E-hPDLSCs phenotype profile, through CD31 and CD34 markers expression and the ability to tube vessel formation. Real Time-Polimerase Chain Reaction (RT-PCR) and western blotting analyses revealed the upregulation of Runt-related transcription factor 2 (RUNX2), Collagen 1A1 (COL1A1), Vascular Endothelial Growth Factor-A (VEGF-A) genes and proteins in the living construct composed by hPDLSCs + E-hPDSCs/BioR. Human PDLSCs + E-hPDLSCs/BioR construct showed also an enhacement of de novo synthesis of osteocalcin. Given that, the extracellular-signal-regulated kinase (ERK)/mitogen activated protein kinase (MAPK) transduction signaling was involved in the osteogenesis and angiogenesis process, the ERK1/2 protein level at biochemical level, in our experimental model, has been investigated. Our results evidenced an upregulation of ERK1/2 proteins level born in the living construct. In conclusion, we believe that the use of the hPDLSCs and E-hPDLSCs coculture togheter with BioR as substrate, could represent an efficient model able to activate through ERK1/2 signaling pathway the osteoangiogenesis process, and then representing a new potential engineered platform for surgeons during the repair and the healing of bone defects.
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Sex assessment is a crucial part of the biological profile in forensic and archaeological context, but it can be hardly performed in cases of commingled and charred human remains where DNA tests often are not applicable. With time literature have analyzed the sexual dimorphism of teeth (and especially canines), but very few articles take into consideration the teeth volume, although with time several technologies have been introduced in order to assess 3D volume (CT-scan, laser scanner, etc.). This study aims at assessing the sexual dimorphism of dental and pulp chamber volumes of a sample of canines. Cone beam computed tomography analyses were performed by 87 patients (41 males and 46 females, aged between 15 and 83 years) for clinical purposes, and were acquired in order to measure canine volumes. Results show that the dental volume amounted to 0.745 cm(3) (SD 0.126 cm(3)) in males, 0.551 cm(3) (SD 0.130 cm(3)) with a statistically significant difference (p<0.01). A diagnostic threshold of 0.619 cm(3) was stated, which provides a percentage of correct answer of 80.5% in the chosen sample. The novel method was then applied with success to 7 archaeological: where in all the cases the results were concordant with those provided by the assessment of the cranium and pelvis. The study adds a contribution to the wide analysis of dental sexual dimorphism confirming the statistically significant differences of volume between males and females and providing a method for the diagnosis of sex applicable to forensic cases.
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Diente Canino/anatomía & histología , Análisis para Determinación del Sexo , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Tomografía Computarizada de Haz Cónico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Tamaño de los Órganos , Proyectos Piloto , Factores SexualesRESUMEN
STATEMENT OF THE PROBLEM: Polyvinyl siloxane materials of various consistencies have been tested to reduce defects commonly associated with different definitive impression techniques. PURPOSE: The purpose of this in vitro study was to compare the number of visible defects within the surface of a new 3-phase, 2-step impression injection technique with the number found in the monophase and in the conventional 2-phase, 1-step and 2-phase, 2-step impression techniques. MATERIAL AND METHODS: Two complete crown abutment preparations were impressed 10 times for each of these 4 techniques, which gave 20 abutment impressions for each group. The 3-phase, 2-step impression--injection technique included extra-light--body impression material added for the impression and injected after reinsertion. After the removal of all of these impressions, an examiner counted the number of open voids and bubble-like enclosed voids visible to the naked eye at a working distance of approximately 150 mm. Only the defects in the area of the prepared abutments were included in the assessment. RESULTS: The frequency of defects ranged from 100% of the impressions in the monophase group to 5% with the new 3-phase, 2-step impression injection technique. No statistical differences were seen between the two 2-phase (1-step and 2-step) impression techniques, although there were numerically fewer impressions with defects with 2 steps (45%) than with 1 step (55%). The 3-phase, 2-step impression injection technique had the greatest accuracy, with fewer specimens with defects (5%) than with either of the 2-phase techniques, although these differences did not reach statistical significance. CONCLUSIONS: The 3-phase, 2-step impression injection technique provides improved defect-free reproduction of detail, showing fewer defects than other impression techniques.
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Materiales de Impresión Dental/química , Técnica de Impresión Dental , Polivinilos/química , Siloxanos/química , Coronas , Pilares Dentales , Técnica de Impresión Dental/instrumentación , Elastómeros/química , Humanos , Ensayo de Materiales , Polimerizacion , Porosidad , Propiedades de Superficie , Factores de Tiempo , Preparación Protodóncica del Diente/métodos , ViscosidadRESUMEN
PURPOSE: The aim of the study was to analyze the characteristics of implant dentistry claims in Italy based on insurance company technical reports for malpractice claims. MATERIALS AND METHODS: One hundred twenty-one technical reports of cases of professional malpractice in implant dentistry between 2006 and 2010 were included in the study. Data included the sex and age of the patient and dentist, the kind of negligence claimed, and the damages awarded as a consequence of the alleged misconduct. RESULTS: Of the cases examined in this study, 9.9% went to court. The patients were female in 73.6% of the cases. Most of the technical errors were committed during implant insertion (82.6%). In 50.4% of cases, the technical error involved the surrounding structures, such as damage to the inferior alveolar nerve (32.2%) or the lingual nerve (2.5%), invasion of the maxillary sinus (9.1%), or pulpal dental necrosis in adjacent teeth (6.6%). Incomplete clinical documentation was apparent in 54.5% of cases. In 9.9% of cases, a civil suit had already been filed before a visit, and medicolegal advice from the insurance expert had been procured. CONCLUSION: The discrepancy between the total number of cases examined and those that went to court indicates that implant malpractice claims in Italy are most often settled out of court. The large number of intraoperative errors seen and the high proportion of injuries to surrounding structures suggest that implant dentists would benefit from further specific training. Also, clinical documentation vital to a defense against any claims relating to professional misconduct was incomplete or absent in more than half of the cases.
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Implantación Dental Endoósea/estadística & datos numéricos , Implantes Dentales/estadística & datos numéricos , Revisión de Utilización de Seguros/estadística & datos numéricos , Mala Praxis/legislación & jurisprudencia , Adulto , Compensación y Reparación/legislación & jurisprudencia , Necrosis de la Pulpa Dental/epidemiología , Registros Odontológicos/legislación & jurisprudencia , Femenino , Humanos , Revisión de Utilización de Seguros/legislación & jurisprudencia , Seguro Odontológico/legislación & jurisprudencia , Seguro Odontológico/estadística & datos numéricos , Complicaciones Intraoperatorias/epidemiología , Italia/epidemiología , Responsabilidad Legal , Traumatismos del Nervio Lingual/epidemiología , Masculino , Nervio Mandibular/patología , Seno Maxilar/lesiones , Persona de Mediana Edad , Traumatismos del Nervio Trigémino/epidemiologíaRESUMEN
The aim of the present clinical report was to describe the use of a patient's extensive fixed prosthesis, where the supporting teeth were hopeless, for fabricating an interim immediate complete denture. The present procedure was used to replicate the vertical dimension, phonetic and aesthetic of the existing fixed prostheses as part of an immediate denture and a final complete denture.
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This article describes the high esthetic value of a single-tooth implant immediately placed in the anterior region using a flapless approach and a custom-made zirconia-ceramic abutment and crown. The case reported illustrates the practical procedure involved in developing natural esthetics with a custom-made zirconia-ceramic prosthesis and abutment. The technique is relatively simple, can be used in a variety of clinical situations, and provides excellent results from an esthetic point of view, which is demonstrated by the results of pink esthetic scores (PES) (9 ± 0.2) and white esthetic scores (WES) (7 ± 0.5) after 4 years.
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Pilares Dentales , Implantación Dental Endoósea/métodos , Implantes Dentales de Diente Único , Porcelana Dental , Estética Dental , Carga Inmediata del Implante Dental , Coronas , Femenino , Humanos , Incisivo , Maxilar , Persona de Mediana Edad , Planificación de Atención al Paciente , Alveolo Dental/cirugía , CirconioRESUMEN
STATEMENT OF PROBLEM: Dimensional accuracy when making impressions is crucial to the quality of fixed prosthodontic treatment, and the impression technique is a critical factor affecting this accuracy. PURPOSE: The purpose of this in vitro study was to compare the dimensional accuracy of a monophase, 1- and 2-step putty/light-body, and a novel 2-step injection impression technique. MATERIAL AND METHODS: A stainless steel model with 2 abutment preparations was fabricated, and impressions were made 15 times with each technique. All impressions were made with an addition-reaction silicone impression material (Aquasil) and a stock perforated metal tray. The monophase impressions were made with regular body material. The 1-step putty/light-body impressions were made with simultaneous use of putty and light-body materials. The 2-step putty/light-body impressions were made with 2-mm-thick resin-prefabricated copings. The 2-step injection impressions were made with simultaneous use of putty and light-body materials. In this injection technique, after removing the preliminary impression, a hole was made through the polymerized material at each abutment edge, to coincide with holes present in the stock trays. Extra-light-body material was then added to the preliminary impression and further injected through the hole after reinsertion of the preliminary impression on the stainless steel model. The accuracy of the 4 different impression techniques was assessed by measuring 3 dimensions (intra- and interabutment) (5-mum accuracy) on stone casts poured from the impressions of the stainless steel model. The data were analyzed by 1-way ANOVA and Student-Newman-Keuls test (alpha=.05). RESULTS: The stone dies obtained with all the techniques had significantly larger dimensions as compared to those of the stainless steel model (P<.01). The order for highest to lowest deviation from the stainless steel model was: monophase, 1-step putty/light body, 2-step putty/light body, and 2-step injection. Significant differences among all of the groups for both absolute dimensions of the stone dies, and their percent deviations from the stainless steel model (P<.01), were noted. CONCLUSIONS: The 2-step putty/light-body and 2-step injection techniques were the most dimensionally accurate impression methods in terms of resultant casts.