Preload and Removal Torque of Two Different Prosthetic Screw Coatings-A Laboratory Study.

This study aimed to evaluate the effect of two coating materials, a silicone sealing gel and a polytetrafluoroethylene (PTFE) tape, on the screw preload and removal torque value (RTV) to develop strategies to prevent prosthetic screw loosening. We examined 45 complexes comprising an implant, abutment, and prosthetic screw, of which 15 samples were uncoated, 15 were coated with GapSeal (Hager & Werken GmbH & Co., Duisburg, Germany), and 15 were coated with PTFE tape (MIARCO, Valencia, Spain).

SEM Analysis and Micro-CT Evaluation of Four Dental Implants after Three Different Mechanical Requests-In Vitro Study.

Statement Of Problem: Implant-supported rehabilitations are an increasingly frequent practice to replace lost teeth. Before clinical application, all implant components should demonstrate suitable durability in laboratory studies, through fatigue tests.

Objective: The purpose of this in vitro study was to evaluate the integrity and wear of implant components using SEM, and to assess the axial displacement of the implant-abutment assembly by Micro-CT, in different implant connections, after three distinct mechanical requests.

Influence of Popular Beverages on the Fracture Resistance of Implant-Supported Bis-Acrylic Resin Provisional Crowns: An In Vitro Study.

Implant-supported provisional restorations are critical for improving the esthetics and shaping of the peri-implant tissue. The mechanical properties of these provisional materials can be influenced by saliva, food, beverages, and interactions between these materials in the oral environment. Therefore, the integrity of provisional restorations should be preserved throughout the treatment period.

The Influence of Cleaning Solutions on the Retention of Overdenture Attachment Systems.

Dental-implant-supported reconstructions provide comfort and improvements in prosthetic function, adaptation, and stability over conventional treatment options. The objective of this study was to evaluate the effect of different denture cleansing solutions and their influence on the deterioration and loss of retention of overdenture attachments in a 12-month clinical-use simulation. In this way, ten specimens each of different brands of retentive caps made of Teflon (OT Equator (Rhein83, Bologna, Italy), Locator (Zest Anchors, Escondido, CA, USA), Kerator (KJ Meditech, Gwangiu, Republic of Korea), and Locator R-Tx (Zest Anchors, Escondido, CA, USA)) were immersed in five different cleaning solutions (Kukident (P&G Tech, Oxford Parkway, UK), Benfix (Laboratorios URGO S.

The Influence of Saliva pH on the Fracture Resistance of Two Types of Implant-Supported Bis-Acrylic Resin Provisional Crowns-An In Vitro Study.

Temporary restorations play a fundamental role in oral rehabilitation. A properly adapted implant-supported provisional restoration implies better esthetics, contouring and architectural modeling of the upper peri-implant tissue. This study aimed to evaluate the influence of oral pH on the fracture resistance of implant-supported provisional restorations made with two brands of bis-acrylic resin (LuxaCrown and Protemp™ 4) and to compare the fracture resistance of these two materials.

Fracture Resistance of CAD/CAM Implant-Supported 3Y-TZP-Zirconia Cantilevers: An In Vitro Study.

(1) Introduction: Implant-supported fixed complete dentures are mostly composed of cantilevers. The purpose of this work was to evaluate the fracture resistance of zirconia (Prettau®, second generation, or Ice Zirkon Translucent, first generation) with cantilever lengths of 6 and 10 mm, and zirconia’s fracture resistance in relation to an average bite force of 250 N. (2) Materials and methods: Forty structures were created in CAD/CAM and divided into four groups: group A (6 mm cantilever in IZT), group B (10 mm cantilever in IZT), group C (6 mm cantilever in Pz), and group D (10 mm cantilever in pz).

In Vitro Comparison of Three Intraoral Scanners for Implant-Supported Dental Prostheses.

With continuing technological developments, there have been advances in the field of fixed prosthetics, particularly in impression-taking techniques. These technological advances mean that a wide variety of diagnostic and/or rehabilitation possibilities can be explored without the need for physical models. The aim of this study was to evaluate the accuracy of three intraoral scanners used in oral implant rehabilitation using an extraoral scanner as a reference and varying the scanning area.

Retention Capacity of Original Denture Adhesives and White Brands for Conventional Complete Dentures: An In Vitro Study.

(1) Introduction: Denture adhesives (DAs) promote stability, chewing ability, and quality of life. The objective of this study was to compare the effectiveness of original brand DAs and white brands in their retention of conventional complete dentures. (2) Methods: This study followed the recommendations of the international standard ISO 10873.

Comparison of Mechanical Resistance to Maximal Torsion Stress in Original and Nonoriginal or Compatible Prosthetic Implant Screws: An In Vitro Study.

Micromovements of the implant-abutment connection influence peri-implant bone preservation. The maximal torque after a cycle of implant prosthetic screw tightening using original components of different manufacturers and replicas produced by other companies is evaluated and quantified in this study. A total of 30 Mis Seven® standard platform implants and 30 interfaces were used, and 30 standard platform screws were tested, 10 Mis®, 10 Iconekt®, and 10 Exaktus®.

Survival Rates of Anterior-Region Resin-Bonded Fixed Dental Prostheses: An Integrative Review.

This study aimed to review clinical publications involving anterior-region resin-bonded fixed partial dentures to evaluate their survival rates vis-à-vis their materials and design. An electronic search was conducted using PubMed/MEDLINE to identify articles that reported on the longevity of anterior resin-bonded fixed dental prostheses published between 2000 and 2020. Only primary clinical studies that involved a follow-up after at least 3 years were included in this review.

Comparison of the Masticatory Force (with 3D Models) of Complete Denture Base Acrylic Resins with Reline and Reinforcing Materials.

The reinforcement of acrylic denture base remains problematic. Acrylic prosthesis fractures are commonly observed in prosthodontic practice and have not been reliably resolved. This study compared the resistance to masticatory force of acrylic bases of removable complete conventional prosthesis in 3D upper models.

Comparison of Fracture Resistance in Thermal and Self-Curing Acrylic Resins-An In Vitro Study.

Thermal and self-curing acrylic resins are frequently and versatilely used in dental medicine since they are biocompatible, have no flavor or odor, have satisfactory thermal qualities and polishing capacity, and are easy and fast. Thus, given their widespread use, their fracture resistance behavior is especially important. In this research work, we comparatively analyzed the fracture resistance capacity of thermo and self-curing acrylic resins in vitro.

Clinical evaluation of the implant survival rate in patients subjected to immediate implant loading protocols.

Background: In the past 20 years, several studies and clinical trials have reported similar results for transmucosal implants as compared to submerged implants. Several advantages of immediate loading have been pointed out, such as the reduction of treatment time, trauma reduction, and immediate esthetic and functional improvements.

Objectives: The main objective of this study was to clinically evaluate the implant survival rate in patients with total rehabilitation via implants that underwent immediate loading in the past 5 years.

The Influence of Saliva pH on the Fracture Resistance of Three Complete Denture Base Acrylic Resins.

Methods: Ten prosthesis bases prepared with each brand of resin were subjected to neutral and low pH conditions (pH 7 and pH 4) by submerging them in artificial saliva for 30 days. After exposure, the fatigue resistance of the resins was tested using a Dental CS® Testing Machine. .

Comparison in Four Different Implant Systems of Mechanical Resistance to Maximal Stress in Prosthetic Screws-An In Vitro Study.

Micromovements of the implant-abutment connection influence peri-implant bone preservation. This study evaluates and quantifies the maximal torque after a cycle of implant prosthetic screws tightening using original components. A total of 40 samples were tested: Megagen-Daegu, South Korea; Dentium-Gangnam-Gu, Seoul, Korea; BIOMET 3i-West Palm Beach, FL, USA and BTI-Álava, Spain.

The role of cultural group selection in explaining human cooperation is a hard case to prove.

We believe cultural group selection is an elegant theoretical framework to study the evolution of complex human behaviours, including large-scale cooperation. However, the empirical evidence on key theoretical issues - such as levels of within- and between-group variation and effects of intergroup competition - is so far patchy, with no clear case where all the relevant assumptions and predictions of cultural group selection are met, to the exclusion of other explanations.

Effect of abutment angulation in the retention and durability of three overdenture attachment systems: An in vitro study.

Purpose: This in vitro study investigated and compared the durability and retention of three types of attachments.

Materials And Methods: Three commercially available attachments were investigated: Clix®, Dalbo-Plus® and Locator®. In total, 72 samples of these attachments were placed in the acrylic resin forms and subjected to mechanical testing (5400 cycles of insertion and removal) over the respective ball or Locator abutments immersed in artificial saliva at pH 7 and 37℃.

Inter-Group Conflict and Cooperation: Field Experiments Before, During and After Sectarian Riots in Northern Ireland.

The idea that cooperative groups out-compete less cooperative groups has been proposed as a theoretical possibility for the evolution of cooperation through cultural group selection. Previous studies have found an association between increased cooperation and exposure to inter-group violence, but most have not been able to identify the specific target of cooperation and are based on correlational data making it difficult to establish causality. In this study we test the hypothesis that inter-group conflict promotes parochial altruism (i.

The influence of saliva pH value on the retention and durability of bar-clip attachments.

Purpose: The aim of this study was to compare the durability and retention of 4 types of attachments placed over computer aided design/computer aided manufacturing (CAD/CAM) titanium bars when subjected to different pH conditions.

Materials And Methods: Four commercially available attachments were investigated: Hader Yellow, Hader Red, Ackerman Gold and Ackerman Stainless Steel. These attachments and Ackerman CAD/CAM titanium bars were placed in 2 vessels containing different artificial saliva solutions (pH 7/pH 4) at 37℃ for one month to simulate corrosion conditions, and they were then subjected to mechanical testing (5400 cycles of insertion and removal).

Cooperation and conflict: field experiments in Northern Ireland.

The idea that cohesive groups, in which individuals help each other, have a competitive advantage over groups composed of selfish individuals has been widely suggested as an explanation for the evolution of cooperation in humans. Recent theoretical models propose the coevolution of parochial altruism and intergroup conflict, when in-group altruism and out-group hostility contribute to the group's success in these conflicts. However, the few empirical attempts to test this hypothesis do not use natural groups and conflate measures of in-group and unbiased cooperative behaviour.

Defectors, not norm violators, are punished by third-parties.

Punishment of defectors and cooperators is prevalent when their behaviour deviates from the social norm. Why atypical behaviour is more likely to be punished than typical behaviour remains unclear. One possible proximate explanation is that individuals simply dislike norm violators.

Sequential sampling of Bemisia tuberculata (Bondar, 1923) (Hemiptera: Aleyrodidae) on cassava crop.

Estimate efficiently of the whitefly population (Bemisia tuberculata Bondar) in cassava, to assist in decision making of pest control is one of the advantages of sequential sampling plans. Therefore, the objective of this study was to determine a sequential sampling plan according to two methods of pest management, using biological and/or chemical control. Samples were obtained in a commercial field of 2.

Microstructural characterization of consolidant products for historical renders: an innovative nanostructured lime dispersion and a more traditional ethyl silicate limewater solution.

The conservation and durability of historical renders must be carried out through compatible techniques and materials. An important operation is the restitution of historical renders cohesion, turned friable by the loss of binder, usually due to physical and/or chemical actions. Surface consolidation is based on the use of materials with aggregating properties.

Lost letter measure of variation in altruistic behaviour in 20 neighbourhoods.

Altruistic behaviour varies across human populations and this variation is likely to be partly explained by variation in the ecological context of the populations. We hypothesise that area level socio-economic characteristics will determine the levels of altruism found in individuals living in an area and we use a lost letter experiment to measure altruism across 20 neighbourhoods with a wide range of income deprivation scores in London, UK. The results show a strong negative effect of neighbourhood income deprivation on altruistic behaviour, with letters dropped in the poorest neighbourhoods having 91% lower odds of being returned than letters dropped in the wealthiest neighbourhoods.

Perforated peptic ulcer: main factors of morbidity and mortality.

It is well stated in the literature that medical treatment for peptic ulcer is based on a combination of proton pump inhibitors (PPIs) and antibiotics to eradicate Helicobacter pylori. This treatment is associated with a high rate of immediate success and a low rate of recurrence at 12 months, although it is not effective in all patients. Peptic ulcer (PU) perforation is a serious problem that leads to high complication and mortality rates.