Efficacy of Selective Grinding Guided by an Occlusal Splint in Management of Myofascial Pain: A Prospective Clinical Trial.

BACKGROUND: For patients whose centric relation (CR) has not been considered at the start and during treatment, the task of achieving an occlusal scheme that works together with the temporomandibular joint, the muscles, and the structures of the stomatognathic apparatus becomes a major concern. OBJECTIVE: This study aims to describe a reproducible, predictable and to date unreported procedure of selective grinding guided by an occlusal splint and to analyze condylar position (CP) based on the skeletal pattern. METHODS: A total of 72 symptomatic patients (38 females and 34 males) were classified into three groups: hyperdivergent, intermediate and hypodivergent. CP was quantified by mounted casts on a measures condyle displacement (MCD) device. Helkimo index was also performed in order to assess the severity of the temporomandibular joint (TMJ) disorders attending to clinical dysfunction, occlusal state and anamnestic dysfunction. Once the stability had been obtained, the splint was progressively reduced until the maximum intercuspation (MIC) was achieved. RESULTS: The vertical displacement was found to be significantly different between the hyperdivergent and other two groups (p<0.01). Comparisons of MCD analysis before and after the selective grinding procedure identified a statistically significant difference in the horizontal and vertical CP (p<0.01) between the different groups whereas the Helkimo Index showed a clear improvement of TMJ disorders. CONCLUSION: All facial types, specially the hyperdivergent face type, showed a reduction in condylar displacement (CD) and less craniomandibular symptoms using this procedure, making it an excellent technique for clinicians.

Biomechanical Consequences of the Elastic Properties of Dental Implant Alloys on the Supporting Bone: Finite Element Analysis.

The objective of the present study is to evaluate how the elastic properties of the fabrication material of dental implants influence peri-implant bone load transfer in terms of the magnitude and distribution of stress and deformation. A three-dimensional (3D) finite element analysis was performed; the model used was a section of mandibular bone with a single implant containing a cemented ceramic-metal crown on a titanium abutment. The following three alloys were compared: rigid (Y-TZP), conventional (Ti-6Al-4V), and hyperelastic (Ti-Nb-Zr). A 150-N static load was tested on the central fossa at 6° relative to the axial axis of the implant. The results showed no differences in the distribution of stress and deformation of the bone for any of the three types of alloys studied, mainly being concentrated at the peri-implant cortical layer. However, there were differences found in the magnitude of the stress transferred to the supporting bone, with the most rigid alloy (Y-TZP) transferring the least stress and deformation to cortical bone. We conclude that there is an effect of the fabrication material of dental implants on the magnitude of the stress and deformation transferred to peri-implant bone.

Biomechanical evaluation of oversized drilling technique on primary implant stability measured by insertion torque and resonance frequency analysis.

BACKGROUND: This study evaluated the influence of implant site preparation depth on primary stability measured by insertion torque and resonance frequency analysis (RFA). MATERIAL AND METHODS: Thirty-two implant sites were prepared in eight veal rib blocks. Sixteen sites were prepared using the conventional drilling sequence recommended by the manufacturer to a working depth of 10mm. The remaining 16 sites were prepared using an oversize drilling technique (overpreparation) to a working depth of 12mm. Bone density was determined using cone beam computerized tomography (CBCT). The implants were placed and primary stability was measured by two methods: insertion torque (Ncm), and RFA (implant stability quotient [ISQ]). RESULTS: The highest torque values were achieved by the conventional drilling technique (10mm). The ANOVA test confirmed that there was a significant correlation between torque and drilling depth (p<0.05). However, no statistically significant differences were obtained between ISQ values at 10 or 12 mm drilling depths (p>0.05) at either measurement direction (cortical and medullar). No statistical relation between torque and ISQ values was identified, or between bone density and primary stability (p >0.05). CONCLUSIONS: Vertical overpreparation of the implant bed will obtain lower insertion torque values, but does not produce statistically significant differences in ISQ values. KEY WORDS: Implant stability quotient, overdrilling, primary stability, resonance frequency analysis, torque.

Fracture Resistance of Monolithic High Translucency Zirconia Implant-Supported Crowns.

AIM: To evaluate the resistance to axial forces of screw-retained monolithic high translucency zirconia (mHTZr) crowns compared with high translucency zirconia + feldspathic ceramic (HTZrC) crowns, low translucency zirconia + feldspathic ceramic (LTZrC) crowns, and metal-ceramic (MC) crowns, and also to observe the different fracture patterns between all groups. METHODS: Twenty-four crowns were fabricated (6 of each group) and loaded until failure, using a testing machine with a 5.0-kN load cell. RESULTS: Mean fracture results varied between 1092.7 N (LTZrC group) and 3439.7 N (mHTZr group). No statistically significant differences were found between the HTZrC, LTZrC, and MC groups. However, statistically significant differences (P < 0.05) were found between mHTZr and the other 3 groups. In the MC group, only chipping of the ceramic veneering occurred. In the mHTZr group, when fracturing occurred, it was of the whole structure. Finally, the LTZrC and HTZrC groups suffered both chipping and core fractures. CONCLUSION: High translucency monolithic zirconia implant-supported crowns proved to be the toughest group studied when an axial force was applied. Fracture patterns varied between different materials, chipping being the most common occurrence.

Análisis comparativo de la repetibilidad y reproductibilidad de dos métodos de medición de la dimensión vertical en rehabilitación oral: una revisión sistemática / Comparative analysis of the repeatability and reproducibility of two methods for measuring the vertical dimension in oral rehabilitation: a systematic review

El objetivo de este estudio establecer si el método de evaluación de la dimensión vertical mediante cefalometría y el convencional con rodillos de articulación, consiguen resultados sin diferencias estadísticamente significativas. Realización de una revisión sistemática conforme a la metodología PICO del Centro de Medicina Basada en la Evidencia de Oxford. Se formula una pregunta dirigida al objetivo fijado y se elabora una estrategia de búsqueda empleando MeSH key words específicos derivados de la pregunta en la base de datos PubMed hasta 2015 y libros de rehabilitación oral. Se consultan un total de 833 artículos por título, siendo 26 revisados a texto completo. Se analizan trabajos sobre distintos métodos de determinación de la dimensión vertical, haciendo especial hincapié en los basados en métodos cefalométricos. Finalmente 9 artículos cumplen los criterios de inclusión y se realiza una evaluación crítica del nivel de evidencia. No se ha encontrado suficiente evidencia científica que demuestre la repetibilidad de ambos métodos. Es necesario realizar estudios controlados y aleatorizados que comparen ambos métodos para determinar si son repetibles y reproducibles y obtienen resultados sin diferencias estadísticamente significativas.

The objective of this work was to establish if the method of evaluation of the vertical dimension by cephalometry and the common one with joint rollers, obtains results without statistically significant differences. We carried out a systematic review based on the PICO methodology of the Center for Evidence-Based Medicine for Oxford. A question aimed at the objective was made, and a search strategy was developed using specific MeSH key words derived from the question in the Pubmed database up to 2015 and oral rehabilitation books. A total of 833 items were consulted by tittle, and for 26 of these full text was reviewed. Works on different methods for determining the vertical dimension were studied, with special emphasis on those based on cephalometric methods. Finally 9 articles fulfilled the criteria for inclusion and a critical assessment of the evidence level was performed. We did not find sufficient scientific evidence to demonstrate the repeatability of these methods. It is necessary to realize randomized controlled trials comparing both methods to determine if they were statistically repeatable and reproducible.

Recombinant osteoprotegerin effects during orthodontic movement in a rat model.

BACKGROUND AND OBJECTIVES: Anchorage is one of the most challenging sides in orthodontics. The use of biological modulators that inhibit osteoclasts could be a solution to address these problems and provide new adjunctive approaches. The aim of this study was to assess the effectiveness of recombinant osteoprotegerin fusion protein (OPG-Fc) in orthodontic anchorage. MATERIALS AND METHODS: Two groups of male Sprague-Dawley rats were utilized. The animals in the experimental group received twice-weekly injections with high dose of OPG-Fc (5.0mg/kg) in mesial and distal mucosa of the first molars, and those in the control group received no drugs. Right first maxillary molars were mesialized using a calibrated nickel-titanium spring connected to an anterior mini-screw. Tooth movement was measured by two blinded observers using scanned and magnified stone casts. Receptor activator of nuclear factor κB (RANK), run-related transcription factor 2 (Runx2), type I collagen, vimentin, matrix metalloproteinases 2 and 9, S100 protein and the putative mechanoproteins acid-sensing ion channel (ASIC2) and transient receptor potential vainilloid 4 (TRPV4) were evaluated using immunohistochemistry. RESULTS: OPG-Fc group showed an important decreased in mesial molar movement with only 52%, 31%, and 22% of the total mesial molar movement compared with control group at Days 7, 14, and 21, respectively (P < 0.001). RANK ligand and Runx2 positive cells were severely reduced after OPG-Fc treatment. Periodontal ligament architecture, cell arrangement, and immunohistochemical patter for vimentin, type I collagen and the mechanoproteins TRPV4 and ASIC2 were altered by tooth movement and all these parameters altered by the applied treatment. CONCLUSIONS: OPG-Fc effectively inhibits osteoclastogenesis resulting in improved bone quantity and orthodontic anchorage. Based on present results, OPG-Fc could have clinical utility in preventing undesired tooth movements.

Accuracy of resonance frequency analysis by third generation Osstell® / Precisión del análisis de frecuencia de resonancia mediante Osstell® de tercera generación

The Resonance Frequency Analysis by Osstell® is used in the assessment of primary and secondary implant stability. The aim of this study was to determine its accuracy as a method of testing, checking its repeatability and reproducibility. A pilot study was performed whereby implants were placed in a cow rib to compare several ISQ measurements with the same SmartPeg transducer (repeatability), or with different SmartPegs (reproducibility). Statistical analysis of the data showed a high correlation of the ISQ values obtained in both assays, which suggests that Osstell®analysis can provide high repeatability and reproducibility.

El análisis de frecuencia de resonancia (AFR) por Osstell® se utiliza en la evaluación de la estabilidad primaria y secundaria del implante. El objetivo del presente estudio fue establecer la precisión del AFR mediante Osstell©, como método de prueba empleado en la determinación de la estabilidad implantaria. Se realizó un estudio experimental in vitro, en el que se colocaron implantes en una costilla de vaca y compararon diferentes mediciones del coeficiente de estabilidad del implante (ISQ) obtenidas sobre estos implantes con un mismo transductor SmartPeg (repetibilidad) o con diferentes SmartPegs (reproductibilidad). El análisis estadístico de los datos mostró una elevada correlación de los ISQ obtenidos en ambos ensayos, lo cual sugiere una reproductibilidad y repetibilidad elevada del análisis mediante Osstell.

Influence of orthodontic treatment on temporomandibular disorders. A systematic review.

OBJECTIVES: The aim of this literature systematic review was to evaluate the possible association between malocclusions, orthodontic treatment and development of temporomandibular disorders. MATERIAL AND METHODS: A search was carried out on PubMed-Medline database from January 2000 to August 2013 using the keywords "orthodontics and temporomandibular disorders", "orthodontics and facial pain" and "malocclusion and temporomandibular disorders". Human studies included in the study were those assessing signs and symptoms of temporomandibular disorders in relation to orthodontic treatment. MATERIAL AND METHODS: A search was carried out on PubMed-Medline database from January 2000 to August 2013 using the keywords "orthodontics and temporomandibular disorders", "orthodontics and facial pain" and "malocclusion and temporomandibular disorders". Human studies included in the study were those assessing signs and symptoms of temporomandibular disorders in relation to orthodontic treatment. RESULTS: The search strategy resulted in 61 articles. After selection according to the inclusion/exclusion criteria 9 articles qualified for the final analysis. The articles which linked orthodontics and development of temporomandibular disorders showed very discrepant results. Some indicated that orthodontic treatment could improve signs and symptoms of temporomandibular disorders, but none of them obtained statistically significant differences. CONCLUSIONS: According to the authors examined, there is no evidence for a cause-effect relationship between orthodontic treatment and temporomandibular disorders, or that such treatment might improve or prevent them. More longitudinal studies are needed to verify any possible interrelationship. Key words:Malocclusion and temporomandibular disorders, orthodontics and facial pain, orthodontics and temporomandibular disorders, temporomandibular disorders, temporomandibular dysfunction.

Influencia del Diseño Micro y Macroscópico de la Región Cervical del Implante en la Preservación de Hueso Marginal Perimplantario: Una Revisión Sistemática / Influence of the Micro and Macroscopic Implant Neck Design in the Preservation of Marginal Bone Level: A Systematic Review

El objetivo de esta revisión sistemática fue evaluar los distintos diseños en el cuello del implante (pulido o tratado, con o sin intercambio de plataforma, o con o sin microespiras) y su posible influencia en la pérdida del hueso marginal periimplantario. Se llevo a cabo una revisión sistemática siguiendo la metodología PICO del Centro de Medicina Basada en la Evidencia de la Universidad de Oxford. La pregunta dirigida a la consecución de los objetivos fue: ¿Es el diseño del cuello del implante un factor crítico en la conservación del hueso marginal periimplantario? Se emplearon MeSH keywords específicos en las bases de datos Pubmed y Cochrane. Tres revisores independientes se pusieron de acuerdo en los estudios finalmente incluidos, obteniendo un índice de concordancia kappa de 0,88. De estos, se realizó una evaluación crítica del nivel de evidencia y también del riesgo de sesgo de los RCT mediante la Herramienta Cochrane. Se consultaron 445 artículos por título, incluyendo finalmente un total de 16 artículos a texto completo. La heterogeneidad de estos estudios impidió realizar un meta-análisis. No se encontró evidencia de que una determinada configuración del cuello del implante sea mejor que otra en la conservación del hueso marginal periimplantario y sin embargo, parece que una posición apico-coronal yuxtaósea del cuello pulido del implante respecto a la cresta ósea receptora pudiera ser crítica a ese respecto. No se encontró suficiente evidencia sobre la efectividad de las diferentes configuraciones de la región cervical del implante en la preservación del hueso marginal periimplantario. Son necesarios estudios clínicos controlados y aleatorizados a largo plazo para valorar los efectos de dichas modificaciones.

The aim of this systematic review was to assess whether different implant neck designs (polished or coated, with or without platform switching, either with or without microthreads) influence marginal bone resorption. A systematic review was conducted following the PICO methodology of the Centre for Evidence-Based Medicine of Oxford University. The question to the achievement of objectives was: Is the design of the implant neck a critical factor in the preservation of marginal bone levels? Specific MeSH keywords were used in the Pubmed and Cochrane databases. Three independent reviewers agreed on the studies ultimately included finding a concordance kappa index of 0.86. Of these articles, acritical evaluation of the level of evidence was performed and also the risk of bias of the RCT using the Cochrane tool. Four hundred forty-five items were reviewed by title, eventually including a total of 16 full-text articles. Heterogeneity of these studies made impossible the performance of a meta-analysis. No evidence that a particular configuration of the implant neck was better than another in preserving the peri-implant marginal bone was found, and yet it seems that an apico-coronal position juxta-osseous of the smooth neck of the implant relative to the bone crest could be decisive. Not enough evidence was found on the effectiveness of different configurations of the cervical region of the implant in the periimplant marginal bone preservation. More randomized controlled trials are needed to assess long-term effects of such modifications.

Osteotome sinus floor elevation without grafting material: Results of a 2-year prospective study.

OBJECTIVES: The aim of this prospective clinical trial was to evaluate the success implant rates during 24 months using OSFE procedure without grafting materials. STUDY DESIGN: 42 adult patients (22 female, 15 male) were selected according to Nedir et al´s inclusion criteria of which 5 patients were excluded, due to periapical pathology in adjacent teeth (n=3) and treatment with bisphosphonates (n=2). 37 patients aged 31-68 years were selected. Smokers were divided in two groups depending on the number of cigarettes consumed per day (a) 0-10, (b) 11-20. One patient was excluded because he was lost to follow-up at 24 months A total of 36 threaded implants were placed, ∅4,1mm Straumann® (Straumann AG, Waldenburg, Switzerland) and ∅3,5mm Klockner® (Klockner Implant System, Barcelona, Spain). The most used implant diameter was 4,1 mm (n=29), followed by 3,5 mm (n=7), and length used was 10 mm (n=32) and 8 mm (n=4). Initial RBH ranged from 4 mm to 9 mm. All statistical data were processed using the program R 3.0.2 for windows. RESULTS: A total of 36 threaded implants were placed. Residual bone height (RBH) at implant placement averaged 7,4 ± 0,4 mm. Mean bone gain was 1,8 ± 0,3 mm. Four implants showed a bone gain exceeding 3 mm. Mean implant protrusion length into the sinus amounted to 2.1 ± 0,3 mm. Regarding the relationship between smoking and periodontal probes, no statistically significant differences were found (P=0,25), neither in relation to the number of threads that the implants showed (P=0,29) or bone gain (P=0,79). After 24 months the implant success rate was 91,6%. CONCLUSIONS: Implant rehabilitation of edentulous atrophied posterior maxilla can be safely performed and simplified using the OSFE technique without grafting with reliable long-term results. Key words:Crestal bone loss, dental implants, internal sinus lift, no grafting, osteotome sinus elevation, grafting, sinus floor elevation.