A variation on split-cast mounting for complete denture construction

dThis article describes a variation of the split-cast mounting technique wherein the border of the definitive cast is wrapped with masking tape to form a container for the dental plaster normally used to affix the cast to the articulator. The entire inferior surface of the cast is coated with a thin film of petroleum jelly, and the cast is mounted in the articulator. After the dental plaster has set, the cast is retained by means of the masking tape. The cast is separated from the dental plaster simply by removing the masking tape.

(m,k)-Gur game: Exploiting message discards in order to increase the lifetime and spatial diversity in autonomic wireless sensor networks

The main concern in Wireless Sensor Networks (WSN) algorithms and protocols are the energy consumption. Thus, the WSN lifetime is one of the most important metric used to measure the performance of the WSN approaches. Another important metric is the WSN spatial coverage, where the main goal is to obtain sensed data in a uniform way. This paper has proposed an approach called (m,k)-Gur Game that aims a trade-off between quality of service and the increasement of spatial coverage diversity. Simulation results have shown the effectiveness of this approach. © 2012 IEEE.

In vitro biomechanical evaluation of sagittal split osteotomy fixation with a specifically designed miniplate

Recent studies have evaluated many methods of internal fixation for sagittal split ramus osteotomy (SSRO), aiming to increase stability of the bone segments while minimizing condylar displacement. The purpose of this study was to evaluate, through biomechanical testing, the stability of the fixation comparing a specially designed bone plate to other two commonly used methods. Thirty hemimandibles were separated into three equal groups. All specimens received SSRO. In Group I the osteotomies were fixed with three 15 mm bicortical positional screws in an inverted-L pattern with an insertion angle of 90°. In Group II, fixation was carried out with a four-hole straight plate and four 6 mm monocortical screws. In Group III, fixation was performed with an adjustable sagittal plate and eight 6 mm monocortical screws. Hemimandibles were submitted to vertical compressive loads, by a mechanical testing unit. Averages and standard deviations were submitted to analysis of variance using the Tukey test with a 5% level of significance. Bicortical screws presented the greatest values of loading resistance. The adjustable miniplate demonstrated 60% lower resistance compared to bicortical screws. Group II presented on average 40% less resistant to the axial loading. © 2012 International Association of Oral and Maxillofacial Surgeons.

Modeling Habitat Split: Landscape and Life History Traits Determine Amphibian Extinction Thresholds

Habitat split is a major force behind the worldwide decline of amphibian populations, causing community change in richness and species composition. In fragmented landscapes, natural remnants, the terrestrial habitat of the adults, are frequently separated from streams, the aquatic habitat of the larvae. An important question is how this landscape configuration affects population levels and if it can drive species to extinction locally. Here, we put forward the first theoretical model on habitat split which is particularly concerned on how split distance - the distance between the two required habitats - affects population size and persistence in isolated fragments. Our diffusive model shows that habitat split alone is able to generate extinction thresholds. Fragments occurring between the aquatic habitat and a given critical split distance are expected to hold viable populations, while fragments located farther away are expected to be unoccupied. Species with higher reproductive success and higher diffusion rate of post-metamorphic youngs are expected to have farther critical split distances. Furthermore, the model indicates that negative effects of habitat split are poorly compensated by positive effects of fragment size. The habitat split model improves our understanding about spatially structured populations and has relevant implications for landscape design for conservation. It puts on a firm theoretical basis the relation between habitat split and the decline of amphibian populations. © 2013 Fonseca et al.

The Evolution of Modal Split for Goods Transport in South America

This FAL bulletin analyzes data for commodities traded and transportation used between nine South American countries, during the years 2000, 2006, and 2010.

The Evolution of Modal Split in Freight Transport in South America, 2000-2013

This FAL Bulletin analyzes data on commodities traded and the modes of transport used between nine South American countries, during 2000, 2006, 2010 and 2013. The aim is to identify the current modal split in intraregional freight transport in South America, and to ascertain the level and evolution of trade flows, imbalances and the burden of transport and insurance costs. The authors conclude with some policy recommendations.

MODEL-BASED COMPENSATION FOR BURST MESSAGE LOSS IN WIRELESS NETWORKED CONTROL SYSTEMS: EXPERIMENTAL RESULTS

A recent trend in networked control systems (NCSs) is the use of wireless networks enabling interoperability between existing wired and wireless systems. One of the major challenges in these wireless NCSs (WNCSs) is to overcome the impact of the message loss that degrades the performance and stability of these systems. Moreover, this impact is greater when dealing with burst or successive message losses. This paper discusses and presents the experimental results of a compensation strategy to deal with this burst message loss problem in which a NCS mathematical model runs in parallel with the physical process, providing sensor virtual data in case of packet losses. Running in real-time inside the controller, the mathematical model is updated online with real control signals sent to the actuator, which provides better reliability for the estimated sensor feedback (virtual data) transmitted to the controller each time a message loss occurs. In order to verify the advantages of applying this model-based compensation strategy for burst message losses in WNCSs, the control performance of a motor control system using CAN and ZigBee networks is analyzed. Experimental results led to the conclusion that the developed compensation strategy provided robustness and could maintain the control performance of the WNCS against different message loss scenarios.

Inferior Alveolar Nerve Function After Sagittal Split Osteotomy by Reciprocating Saw or Piezosurgery Instrument: Prospective Double-Blinded Study

Purpose: The aim of this prospective study was to objectively evaluate inferior alveolar nerve (IAN) sensory disturbances in patients who underwent sagittal split ramus osteotomy (SSRO) by comparing 1 side treated with a reciprocating saw with the other side treated with a piezosurgery device.Materials and Methods: Clinical evaluation of IAN sensory disturbance was undertaken preoperatively and at 1 week, 4 weeks, 2 months, and 6 months postoperatively in 20 patients who underwent SSROat the Division of Oral and Maxillofacial Surgery, Araraquara Dental School, Sao Paulo State University. The 20 patients were examined at all periods for IAN functionality by Semmes-Weinstein testing; neither the patients nor the examiner knew which side was treated using piezosurgery or a reciprocating saw.Results: The mean age of the patients was 28.4 years (range, 20 to 48 yr). Before surgery, no patient had impaired function of the IAN in any of the 8 zones in the mental and inferior lip areas. All patients reported feeling the first monofilament at the time of the preoperative test. Seven days postoperatively, all patients reported some kind of altered sensitivity in at least 1 zone evaluated.Conclusions: The results of this study suggest there was no statistically significant difference in the sensitivity of the labiomental area regarding the instrument used to perform the osteotomy. Future studies will focus on enlarging the sample and evaluating the results. (C) 2014 American Association of Oral and Maxillofacial Surgeons

A split-mouth randomized clinical trial of conventional and heavy flowable composites in class II restorations

Objective: The aim of this study was to evaluate the 2-year clinical performance of class II restorations made with a composite resin with two different viscosities.Methods: 47 patients received two class II restorations (n = 94), one made with GrandioSO (conventional viscosity CV), and the other with GrandioSO Heavy Flow (flowable viscosity FV), subjecting both materials to the same clinical conditions. The self-etching adhesive Futurabond M was used for all restorations. The composites were inserted using the incremental technique. The restorations were evaluated using the modified USPHS criteria according to the periods: baseline, 6 months, 1 year and 2 years after restorative procedures.Results: After 24 months, 40 patients attended the recall and 78 restorations were evaluated. In all periods, no secondary caries was observed. After 6 months, there were slightly overall changes of scores for most parameters. After 24 months, the higher number of changes from score Alfa to Bravo was observed for marginal discolouration (32.5% CV and 39.5% FV) and colour match (15% CV and 31.6% FV), followed by proximal contact (25% CV and 23.7% FV) and marginal adaptation (20% CV and 21.1% FV). For wear, surface texture and postoperative sensitivity the changes were very small. Just two restorations were lost during the 24-month follow up. Less than 5% of all restorations showed postoperative sensitivity. Chi-square test showed no significant differences between the two materials for all parameters analysed.Conclusion: After 2 years of clinical service, no significant differences were observed between GrandioSO conventional and GrandioSO Heavy Flow for the parameters analysed. Both materials provided acceptable clinical behaviour in class II restorations. Clinical Significance: This study presents the possibility of using a flowable composite with high filler content, for performing class II restorations. (C) 2014 Elsevier Ltd. All rights reserved.

Canine retraction and anchorage loss Self-ligating versus conventional brackets in a randomized split-mouth study

Objective: To evaluate the velocity of canine retraction, anchorage loss and changes on canine and first molar inclinations using self-ligating and conventional brackets.Materials and Methods: Twenty-five adults with Class I malocclusion and a treatment plan involving extractions of four first premolars were selected for this randomized split-mouth control trial. Patients had either conventional or self-ligating brackets bonded to maxillary canines randomly. Retraction was accomplished using 100-g nickel-titanium closed coil springs, which were reactivated every 4 weeks. Oblique radiographs were taken before and after canine retraction was completed, and the cephalograms were superimposed on stable structures of the maxilla. Cephalometric points were digitized twice by a blinded operator for error control, and the following landmarks were collected: canine cusp and apex horizontal changes, molar cusp and apex horizontal changes, and angulation changes in canines and molars. The blinded data, which were normally distributed, were analyzed through paired t-tests for group differences.Results: No differences were found between the two groups for all variables tested.Conclusions: Both brackets showed the same velocity of canine retraction and loss of anteroposterior anchorage of the molars. No changes were found between brackets regarding the inclination of canines and first molars.

In vitro biomechanical comparison of six different fixation methods following 5-mm sagittal split advancement osteotomies

The sagittal split ramus osteotomy (SSRO) is a surgical technique used widely to treat many congenital and acquired mandibular discrepancies. Stabilization of the osteotomy site and the potential for skeletal relapse after the procedure are still major problems. The aim of this study was to compare the mechanical stability of six methods of rigid fixation in SSRO using a biomechanical test model. Sixty polyurethane replicas of human hemimandibles were divided into six groups. In group I, the osteotomies were fixed with two four-hole titanium miniplates; in group II, with one four-hole miniplate; in group III, with one four-hole miniplate + a bicortical screw; in group IV, with a grid miniplate; in group V, with a four-hole locking miniplate; and in group VI, with a six-hole miniplate. A linear load in the premolar region was applied to the hemimandibles. The resistance forces (N) needed to displace the distal segment by 1, 3, and 5 mm were recorded and the data transmitted from the load cell to a computer. One-way analysis of variance with Tukey's post hoc test was performed to compare the means between groups. For the three displacement conditions, there was a strong tendency for the 2.0-mm plate + screw and the grid plate to have higher values.

Antimicrobial photodynamic therapy as an adjunct to non-surgical treatment of aggressive periodontitis: a split-mouth randomized controlled trial

Background: The management of aggressive periodontitis (AgP) represents a challenge for clinicians because there are no standardized protocols for an efficient control of the disease. This randomized controlled clinical trial evaluated the effects of repeated applications of antimicrobial photodynamic therapy (aPDT) adjunctive to scaling and root planing (SRP) in patients with AgP. Methods: Using a split-mouth design, 20 patients with generalized AgP were treated with aPDT + SRP (test group) or SRP only (control group). aPDT was applied at four periods. All patients were monitored for 90 days. Clinical, microbiologic, and immunologic parameters were statistically analyzed. Results: In deep periodontal pocket analysis (probing depth [PD] >= 7 mm at baseline), the test group presented a decrease in PD and a clinical attachment gain significantly higher than the control group at 90 days (P < 0.05). The test group also demonstrated significantly less periodontal pathogens of red and orange complexes and a lower interleukin-1 beta/interleukin-10 ratio than the control group (P < 0.05). Conclusion: The application of four sessions of aPDT, adjunctive to SRP, promotes additional clinical, microbiologic, and immunologic benefits in the treatment of deep periodontal pockets in single-rooted teeth in patients with AgP.