Estudio comparativo in vitro del comportamiento de las cerámicas de recubrimiento según el núcleo:óxido de circonio y metal.

Introducción: La creencia de que la prótesis fija sin metal va a modificar el espectro restaurador tradicional siempre ha encontrado un obstáculo: la naturaleza intrínsecamente quebradiza de la cerámica dental. A principios de los años noventa, con el objetivo de subsanar esta complicación, apareció la circona (óxido de circonio), que actuando como material de núcleo de la restauración dotaba a ésta de gran resistencia. La complicación técnica que se observa en las restauraciones de óxido de circonio, en la mayoría de los estudios clínicos con un periodo de observación mínimo de tres años es, la fractura dentro de la propia cerámica de recubrimiento (chipping) Objetivos: 1.Analizar la resistencia a la fractura de la cerámica de revestimiento en coronas de recubrimiento completo sobre núcleos internos de distinta naturaleza (Metál y Cerámica). 2.Analizar, mediante microscopía óptica y electrónica (SEM), las muestras ensayadas para observar el tipo de fractura producida y la ubicación de la misma. Material y Métodos: Se realizó un ensayo de carga estática sobre 120 coronas de recubrimiento completo, en las que se analizó el comportamiento de la porcelana de recubrimiento dependiendo de su núcleo subyacente (metálico y de circona). Una vez fracturadas las muestras fueron analizadas en su superficie y en su interior para observar cambios estructurales de las mismas. Resultados: Los valores de resistencia y los tipos de fracturas observadas en el estudio fueron: IPS e.maxZirCAD+IPS e.maxCeram: 1773,92 N (60% cohesivas); IPS e.maxZirCAD+IPS e.maxZirPress: 1818,02 N (85% cohesivas); Lava™ FrameZirconia+ Lava ™ Ceram: 2211 N (70% cohesivas); Cr-Ni (Rexillium V)+ IPS d.SIGN: 2310,49N (100% adhesivas); Cr-Ni (Rexillium V)+ IPS InLine: 1933,17 N (90% adhesivas); Cr-Ni (Rexillium V)+ IPS InLinePoM: 1325,74 N (85% adhesivas). Conclusión: Todas las porcelanas de recubrimiento analizadas superaron ampliamente los valores medios de resistencia para un correcto comportamiento clínico establecidos por la normativa ISO 6872Objective: To study the behavior of six types of porcelain-veneered crowns with zirconia and metal cores when subjected to static compressive loading. Methods: 120 individual full coverage crowns were studied. Crowns were divided in to six groups: Group I: Ivoclar IPS e.max Zir-CAD crowns (Core: IPS e.max ZirCAD; Porcelain Veneer: IPS e.max Ceram); Group II: Ivoclar IPS e.max ZirPress crowns (Core: IPS e.max ZirCAD; Porcelain Veneer: IPS e.max ZirPress); Group III: 3M ESPE Lava™ crowns (Core: Lava ™ Frame Zirconia ®; Porcelain Veneer: Lava ™ Ceram); Group IV: metal-ceramic crowns (Core: Rexillium V nickel chrome alloy; Porcelain Veneer: IPS d.SIGN ceramic); Group V: metal-ceramic crowns (Core: Rexillium V nickel chrome alloy; Porcelain Veneer: IPS InLine ceramic); Group VI: metal-ceramic crowns (Core: Rexillium V nickel chrome alloy; Porcelain Veneer: IPS InLine PoM ceramic). The compression test was carried out using an Instron 4202 testing machine. The load applicator descended onto the sample exercising continuous vertical force with a crosshead speed of 0.5 mm per second, moving vertically downwards perpendicular to the occlusal zone. Results: In the porcelain veneer compressive test, Group IV(2310.49 N), Group III (2210.95 N), Group II (1818.01 N), Group I (1773.92 N), Group V ( 1933,2 N), Group VI (1325,7 N). Conclusions: Resistance to compressive loading for the metal-ceramic and Lava™ samples obtained an average surface fracture value that was significantly greater in comparison with Groups I, II, V and VI. All the porcelain veneers analyzed far surpassed average compression loads subjected during mastication as established by ISO 6872

Treatment and restoration of adult dentoalveolar trauma: a clinical case report

Adult dentoalveolar trauma most often occurs in the context of sports activities and traffic accidents. Coronal fractures are the most common type of lesion, followed by tooth luxation. We present the case of a 25-year-old woman who suffered alveolar bone damage and coronal fractures of the upper incisors, with extrusive luxation of the right central incisor, as the result of a fall. On the first visit, manual reduction of the buccal plate was carried out under local anesthesia, with repositioning of the right central incisor and splinting to the neighboring teeth. Composites were used to restore the coronal fractures. After one month, both upper central incisors and the right lateral incisor were subjected to endodontic treatment. Internal bleaching of the right lateral incisor was also carried out, due to pigmentation secondary to pulp necrosis. At follow-up 5 months later, the alveolar bone fracture was seen to have healed. Definitive anterior restorative treatment with porcelain veneers was therefore carried out. After two years the patient remains asymptomatic and in good dental condition

In vivo evaluation of three-dimensional of volumetric changes using a CAD/CAM chair-side system : technical procedure

An intraoral digital scanner in combination with specialized three-dimensional surface analysis software monitors volumetric changes to soft tissues or dental restorations. This technology can evaluate the success of a specific technique or medium- or long-term clinical outcomes in both clinical and research situations. This article describes how this technology was used to provide immediate chair-side data analysis without the help of specialized laboratory support

Rehabilitation with implant-supported overdentures in total edentulous patients: a review

Objectives: The main aim of this review article is to discuss implant-supported overdentures (ISOs) as treatment in edentulous patients. Besides, we will try to discuss among the different treatment options in such patients and to analyze their validity when ISOs are compared with other clinical modalities. At the same time, we will try to suggest clinical guidelines supported by current clinical studies. Material and methods: We performed a Medline search and review of pertinent articles on the mentioned subject from 1986 to 2011. As a searching strategy, we used the following words: implant-supported overdentures, attachment systems, Locator attachment, cantilever, fixed prosthesis. Results and conclusions: Implant-supported overdentures constitute an accurate and predictable treatment option and achieve a higher patient's satisfaction. This type of treatment constitutes a cheaper treatment than fixed prostheses and in some patients, with loss of lip support or with an interoclusal space larger than 15 mm, the choice of implant-supported overdentures seems to prevent future aesthetic or phonetic problems

Post-fatigue fracture resistance of metal core crowns: press-on metal ceramic versus a conventional veneering system

Background: The aim of this in vitro study was to compare the mechanical failure behavior and to analyze fracture characteristics of metal ceramic crowns with two veneering systems – press-on metal (PoM) ceramic versus a conventional veneering system – subjected to static compressive loading. Material and Methods: Forty-six crowns were constructed and divided into two groups according to porcelain veneer manufacture. Group A: 23 metal copings with porcelain IPS-InLine veneering (conventional metal ceramic). Group B: 23 metal copings with IPS-InLine PoM veneering porcelain. After 120,000 fatigue cycles, the crowns were axially loaded to the moment of fracture with a universal testing machine. The fractured specimens were examined under optical stereomicroscopy and scanning electron microscope. Results: Fracture resistance values showed statistically significant differences (Student’s t-test) regarding the type of ceramic veneering technique ( p =0.001): Group A (conventional metal ceramics) obtained a mean fracture resistance of 1933.17 N, and Group B 1325.74N (Press-on metal ceramics). The most common type of fracture was adhesive failure (with metal exposure) ( p =0.000). Veneer porcelain fractured on the occlusal surface following a radial pattern. Conclusions: Metal ceramic crowns made of IPS InLine or IPS InLine PoM ceramics with different laboratory techniques all achieved above-average values for clinical survival in the oral environment according to ISO 6872. Crowns made with IPS InLine by conventional technique resisted fracture an average of 45% more than IPS InLine PoM fabricated with the press-on techniqu

Impression of multiple implants using photogrammetry: description of technique and case presentation

Aim: To describe a technique for registering the positions of multiple dental implants using a system based on photogrammetry. A case is presented in which a prosthetic treatment was performed using this technique. Study Design: Three Euroteknika® dental implants were placed to rehabilitate a 55-year-old male patient with right posterior maxillary edentulism. Three months later, the positions of the implants were registered using a photogrammetry-based stereo-camera (PICcamera®). After processing patient and implant data, special abut - ments (PICabutment®) were screwed onto each implant. The PICcamera® was then used to capture images of the implant positions, automatically taking 150 images in less than 60 seconds. From this information a file was obtained describing the relative positions - angles and distances - of each implant in vector form. Information regarding the soft tissues was obtained from an alginate impression that was cast in plaster and scanned. A Cr-Co structure was obtained using CAD/CAM, and its passive fit was verified in the patient's mouth using the Sheffield test and the screw resistance test. Results and Conclusions: Twelve months after loading, peri-implant tissues were healthy and no marginal bone loss was observed. The clinical application of this new system using photogrammetry to record the position of multiple dental im - plants facilitated the rehabilitation of a patient with posterior maxillary edentulism by means of a prosthesis with optimal fit. The prosthetic process was accurate, fast, simple to apply and comfortable for the patient

Biologically oriented preparation technique (BOPT) for implant-supported fixed prostheses

A patient of 58 years of age without medical problems came to the clinic due to missing teeth in the upper posterior region and to change the partial fixed prosthesis in the upper anterior area. Proposed treatment: surgical phase of three conical shape tapering implants with prosthetic platform in occlusal direction with mechanize collar tissue level with fixtures to place implant-supported metal-ceramic restorations. In the anterior area, a zirconium oxide fixed partial prosthesis was vertical preparation of the tooth?s. When preparing teeth to receive fixed prostheses, the definition and shape of finish lines has been a subject of endless discussion, modification, and change ever since the beginnings of restorative prosthetic dentistry. The BOPT technique (biologically oriented preparation technique) was first described in the context of tooth-supported restorations but has recently been applied to dental implants with the aim of ensuring healthy peri-implant tissue and creating the possibility of modeling the peri-implant sulcus by modifying prosthetic emergence profiles. Vertical preparation of teeth and abutments without finish line on implants is a technique which was found to be adequate for ensuring the remodeling and stability of peri-implant tissues

Immediate placement of single implant simultaneously with immediate loading in a fresh socket associated to periapical infection: a clinical case report

Early restoration of the masticatory function, phonatory and aesthetics is some of the current goals of the therapy based on endosseous implants. Facing the classic protocols of implant insertion, which recommend a period of several months between extraction and implant placement, alternatives have been developed that demonstrate that immediate implant placement after tooth extraction permits adequate osseointegration, even in those cases where there is a periapical disease. The immediate restoration of implants after placement is a possibility where aesthetic requirements are high. This article presents a case with immediate implant placement and immediate loading of a first upper premolar with prior periapical pathology due to a vertical fracture. The immediate prosthetic was performed using the extracted crown, which is adapted to be attached to a titanium temporary abutment using a resin cement. After a 4 month healing period work began on the final prosthetic crown. The screw crown was made of zirconium oxide with a covering feldspathic ceramic. At the 12-month follow-up, there were no mechanical or biological complications. The patient gave high satisfaction marks for the overall treatment, giving visual analogue scale score of nine. Immediate post-extraction implants have arisen as an alternative to traditional implants on completely healed bone. Their main aim is to reduce treatment time and number of surgical procedures, along with other objectives such as reduced bone re-absorption and improved aesthetics

Oral rehabilitation with dental implants in patients with recessive dystrophic epidermolysis bullosa : a retrospective study with 2-15 years of follow-up

Epidermolysis bullosa (EB) comprises a group of hereditary disorders characterized by mechanical fragility of the skin and mucous membranes, with the development of blisters and vesicles in response to minimum tissue friction. Recessive dystrophic epidermolysis bullosa (RDEB) with generalized involvement is the most common subtype in the oral cavity. The present study was carried out to investigate dental implant survival, peri-implant tissue condition, patient satisfaction, and the impact of treatment upon the quality of life of patients with RDEB rehabilitated with implants and full-arch implant-supported prostheses. Thirteen patients with RDEB underwent dental implant treatment between September 2005 and December 2016. A retrospective study was made to analyze implant survival, peri-implant tissue health and patient satisfaction. A total of 80 implants were placed (42 in the maxilla and 38 in the mandible) in 13 patients between 20-52 years of age and diagnosed with RDEB. All the implants were rehabilitated on a deferred basis with 20 full-arch prostheses. Fifteen fixed prostheses and 5 implant-supported overdentures were placed. The implant survival rate was 97.5% after a mean follow-up of 7.5 years after prosthetic loading. Fifty percent of the implants showed mucositis at the time of evaluation. Probing depth was maintained at 1-3 mm in 96.2% of the implants, and bleeding upon probing was observed in 67.5% of the implants. There was a high prevalence of bacterial plaque (85%). The treatment of edentulous patients with RDEB by means of implants and implant-supported prostheses is predictable as evidenced by the high success rate, and improves patient self-esteem and quality of life

Methodology in specimen fabrication for in vitro dental studies : standardization of extracted tooth preparation

Specimen preparation for in vitro study suffers a general lack of methodological homogeneity, as well as a lack of uniformity in the materials selected for fabricating them. This situation prevents comparisons between studies. When a specimen is not of dental origin it is not possible to study adhesion or bonding techniques realistically. The objective is to design and implement a method of specimen preparation that permits universal standardization for use in in vitro studies. A metal stump of specified dimensions was designed and fabricated by hand. It was scanned, the data digitalized, perfecting and standardizing the dimensions. Ten human molars were adapted to the size and shape of a standard milling block. A Cerec 3D inLab Cerec milling unit was used to prepare the molars to match the digitalized model. Ten specimens with identical dimensions were obtained. CAD-CAM technology allows the preparation of natural extracted teeth to be standardized and could be used to establish a reproducible method that would facilitate comparison between different in vitro studies, and reduce bias arising from variations in sample fabrication