Apertura mandibular normal con bloqueo articular. Revisión a partir de un hallazgo casual

Después de observar la existencia de un caso de bloqueo articular y apertura normal, nos debemos preguntar si diagnosticamos todos los bloqueos articulares, dándose unas pautas para intuir su presencia

Topes en prótesis parcial removible. Realización y diseño actual

El concepto de soporte fue introducido en relación con los retenedores directos por BONWILL, a finales del siglo XIX, cuando estableció los primeros principios fundamentales de los retenedores directos, indicando la absoluta necesidad de la confección del tope oclusal de los mismos para evitar el enclavamiento en la encía de los elementos retenedor y recíproco (3), así como de toda la prótesis en general(9)..

Ion release from dental casting alloys as assessed by a continuous flow system: Nutritional and toxicological implications

Objectives: The aims of this study were to quantify the metallic ions released by various dental alloys subjected to a continuous flow of saliva and to estimate the nutritional and toxicological implications of such a release. Methods: Four pieces of three nickel-based, one noble, one high-noble and two copper-aluminum alloys were cast and then immersed in a continuous flow of artificial saliva for 15 days. To simulate three meals a day, casts were subjected to thrice-daily episodes, lasting 30 min each and consisting of pH decreases and salinity increases. After 15 days, the metallic ions in the artificial saliva were analyzed. Data were expressed as averaged release rate: microg/cm2/day of ion released for each alloy. The highest value of 95% Cl of each ion was adapted to a hypothetical worst scenario of a subject with 100 cm2 of exposed metal surface. The results were compared with the tolerable upper daily intake level of each ion. Results: The copper-aluminum alloys released copper, aluminum, nickel, manganese and iron. The nickel-based alloys essentially released nickel and chromium, while the beryllium-containing alloy released beryllium and significantly more nickel. The noble and high-noble alloys were very resistant to corrosion. The amount of ions released remained far below the upper tolerable intake level, with the exception of nickel, released by beryllium-containing nickel-based alloy, whose levels approach 50% of this threshold. Significance: The daily amount of ions released seems to be far below the tolerable upper intake levels for each ion

Influence of Matrix Type on Surface Roughness of Three Resins for Provisional Crowns and Fixed Partial Dentures

Purpose: This study evaluated the effect of matrix type on the surface roughness of resins for provisional crowns and fixed partial dentures. Materials and methods: Ninety specimens of two acrylic resins (Trim II, Tab2000) and one bis-acryl composite (Protemp II Garant) were fabricated using one of three matrices: irreversible hydrocolloid (Cavex CA37), poly(vinyl siloxane) (Aquasil) or vacuum-formed matrix (Bio-flow Hard). The sample size for each resin-matrix combination was 10. The vestibular face of one natural maxillary central incisor was used as a model to fabricate all the specimens, following the custom fabrication technique. The average roughness measurements, Ra (mum), were obtained using a profilometer, and the data were analyzed using Kruskal-Wallis and Mann-Whitney U-tests. The results were contrasted against the surface roughness of the tooth using a one-sample t-test. Results: Aquasil and vacuum-formed matrix had a smoother surface than Cavex CA37 regardless of the resin tested (p < 0.05). Protemp II Garant had the smoothest surface regardless of the matrix used, with no significant differences when polymerized against the three different matrices. Trim II polymerized against Cavex CA37 had a rougher (p < 0.05) surface than Aquasil or vacuum-formed matrix. Tab2000 had the smoothest surface (p < 0.05) when polymerized against a vacuum-formed matrix. Conclusions: There is no universal matrix that produces the smoothest surface: this depends on the compatibility between the resin and the matrix. Protemp II Garant polymerized against Cavex CA37 matrix yields a surface that is smooth enough not to require polishing unless this surface is adjusted

Signos de trastorno interno de la ATM sin dislocación meniscal ni enfermedad activa. Revisión a partir de un caso con exploración axiográfica y RMN

En la disfunción cráneomandibular se pueden presentar diversos signos, entre los chasquidos articulares. El presente trabajo hace una revisión a partir de un caso con chasquido articular y sin dislocación, lo cual induce a extremar el diagnóstico por implicaciones terapéuticas posteriores

Is the side with the best masticatory performance selected for chewing?

Objective: This study assessed the degree of relationship between masticatory laterality and lateral asymmetry of masticatory performance using silicon pieces enclosed in a latex bag. Design: Forty-two young adults with natural dentition participated in this cross-sectional, observational study. They performed four different masticatory assays, each consisting of five trials of chewing three pieces of silicon for 20 cycles. In one assay, they were asked to masticate unbagged silicon free-style, whilst in the three other assays they were asked to masticate bagged silicon freestyle, unilaterally on the right-hand side and unilaterally on the left-hand side. The preferred chewing side was determined by calculating the asymmetry index for both the free-style assays. Masticatory performance was determined by sieving the silicon particles and the cycle duration was also recorded. Data were analysed using independent samples or paired t-test and linear regression. Results: Masticatory function using the bagged silicon was similar to that using the unbagged silicon. A significant and positive relationship was observed between the preferred chewing side expressed as the asymmetry index and the side with better masticatory performance. Alternate unilateral chewers demonstrated better masticatory performance than unilateral chewers. However, when free-style and unilateral chewing were compared for each subject, unilateral chewing was found to be as efficient as -or even more efficient than - free-style chewing. Conclusions: There is a positive association between the preferred chewing side and the more efficient side. Alternate unilateral mastication per se does not promote better masticatory performance than consistently unilateral mastication

Reproducibility of lateral excursive tooth contact in a semi-adjustable articulator depending on the type of lateral guidance

The purposes of this study were (i) to compare the reproducibility of lateral tooth contacts of casts mounted in a semi-adjustable articulator when condylar guidance was set by different methods and (ii) to assess the margin of error of the variations of condylar guidance without changing lateral tooth contacts, depending on the type of lateral guidance. In subjects with different types of lateral guidance, intraoral lateral tooth contacts identified with occlusal registration strips were compared with those identified by use of a semi-adjustable articulator, setting the condylar guidance in four different ways: using protrusive wax wafers, by axiography and by adding and subtracting 5 degrees from the value of condylar guidance obtained by protrusive wax wafers. Tolerance to variations of condylar guidance without changing lateral tooth contacts was determined by increasing and decreasing the value of condylar guidance until lateral tooth contacts changed. Different ways of setting condylar guidance on a semi-adjustable articulator give rise to different values of condylar guidance in the same subject. The occlusal repercussions of these variations of condylar guidance values depend on the type of lateral guidance. Canine protection had the greatest tolerance to variations in the setting of condylar guidance without changing lateral occlusal contacts

Estudio preliminar de la liberación de iones metálicos de aleaciones usadas en prótesis fija

En los últimos años estamos asistiendo a un marcado aumento de la utilización de aleaciones metálicas no nobles, como alternativa a las aleaciones de alto contenido en oro. Estas aleaciones son básicamente de dos tipos: base cobre y base níquel. Su coste es más asequible y, además, las aleaciones de base cobre poseen una apariencia que recuerda al oro

Estudio clínico de puentes en extensión

Se han estudiado clínica y radio lógicamente un total de 20 puentes en extensión, de pacientes que han acudido a la Clínica Odontológica de la Universidad de Barcelona. Por estos y otros motivos los resultados clínicos son de un buen número de años de servicios y, aunque muy discutidos, siguen utilizándose en la práctica odontológica

Relationship between chewing side preference and handedness and lateral asymmetry of peripheral factors

Objective: To determine whether chewing side preference is related to handedness and lateral asymmetry of occlusal characteristics, muscular force and temporomandibular disorders (TMD) in a dentate population. Design: One hundred and seventeen dentate adults participated in this cross-sectional study. Static and dynamic occlusal characteristics were determined at the maximal intercuspal position and at the lateral excursions by scanning interocclusal records and analysing them using image software. Unilateral maximum bite force and finger-thumb grip force were measured by means of a gnathodynamometer. TMD were assessed according to the Research Diagnostic Criteria for TMD. Chewing side preference and masticatory laterality were determined by observing the jaw's movement while each subject chewed silicone. Asymmetry or side difference of the variables was calculated. Correlation between side difference variables and masticatory laterality was studied using Spearman correlation coefficient. Results: Fifty-nine subjects chewed on the right, 15 on the left and 43 chewed on both sides. There was no relationship between preferred chewing side and handedness, lateral asymmetry of TMD or side difference in finger-thumb grip force. Significant and positive correlations were observed between masticatory laterality and side differences in bite force and side differences in occlusal contact area at intercuspal position (P<0.01). Conclusions: Chewing side preference in a dentate population is related to lateral asymmetry of bite force and asymmetry of occlusal contact area at the intercuspal position but not to handedness