Reinforcement of 3D-printed resins for denture base by adding aramid fibers: Effect on mechanical, surface, and optical properties.

Purpose: The present study evaluated the mechanical, surface, and optical properties of 3D-printed resins for removable prostheses reinforced by the addition of aramid fibers.

Materials And Methods: According to ISO 20795-1:2013 standards, specimens were printed using a digital light processing 3D printer and divided into two groups (n = 06/group): 3D-printed resin for denture base as the control group, and a group with the same 3D-printed resin in addition of 5% aramid fibers as the experimental group. Red aramid fibers were chosen for aesthetic characterization.

Influence of denture-bearing conditions on masticatory function and patient-reported outcomes measures.

Purpose: To investigate the influence of different denture-bearing conditions on the masticatory function and patient-reported outcome measures (PROMs) of complete denture wearers.

Methods: Sixty edentulous patients were selected and allocated into two groups according to the American College of Prosthodontics' (ACP) classification: non-atrophic (NAT) (Classes I and II) (n = 24) and atrophic (AT) (Classes III and IV) (n = 36). All patients received new complete dentures (CDs).

Dental implant and abutment in PEEK: stress assessment in single crown retainers on anterior region.

Objective: Stress distribution assessment by finite elements analysis in poly(etheretherketone) (PEEK) implant and abutment as retainers of single crowns in the anterior region.

Materials And Methods: Five 3D models were created, varying implant/abutment manufacturing materials: titanium (Ti), zirconia (Zr), pure PEEK (PEEKp), carbon fiber-reinforced PEEK (PEEKc), glass fiber-reinforced PEEK (PEEKg). A 50 N load was applied 30 off-axis at the incisal edge of the upper central incisor.

Effects of disinfection with a vinegar-hydrogen peroxide mixture on the surface characteristics of denture acrylic resins.

Objective: This study aimed to investigate changes in the surface characteristics of two denture resins when disinfected with a vinegar-hydrogen peroxide (VHP) mixture.

Materials And Methods: Microwave-polymerized or 3D printed acrylic resin disks were immersed for 900 min (simulating 90 daily uses) in the following solutions (N = 10): water; 0.5% sodium hypochlorite; hydrogen peroxide and water dilution (1:1 ratio); vinegar and water dilution (1:1 ratio); and VHP mixture.

Mechanical and surface properties of Co-Cr alloy produced by additive manufacturing for removable partial denture frameworks.

Statement Of Problem: Conventional analog methods have been replaced with digital methods for removable partial denture (RPD) frameworks. However, limited information is available regarding the build direction of RPD frameworks and its effect on properties.

Purpose: The purpose of this in vitro study was to evaluate the mechanical and surface properties of the cobalt chromium (Co-Cr) alloy produced at different build angles by the laser powder bed fusion additive manufacturing (AM) technology used for RPD framework fabrication.

Performance of complete dentures fabricated with the simplified and the traditional technique: A randomized clinical trial.

Statement Of Problem: The simplified technique has been recommended for the fabrication of removable complete dentures. However, a consensus regarding the performance of the simplified and the traditional techniques is lacking.

Purpose: The purpose of this randomized clinical trial was to compare the performance of prostheses fabricated with the simplified and the traditional techniques.

Effect of macrogeometry and bone type on insertion torque, primary stability, surface topography damage and titanium release of dental implants during surgical insertion into artificial bone.

This study investigated the influence of implant macrogeometry and bone type on insertion torque (IT), primary stability (ISQ), surface topography damage, and the amount of titanium (Ti) released during insertion. Forty implants with different macrogeometries (Facility - Cylindrical with spiral-shaped threads; Alvim - Tapered with buttress-shaped threads) were inserted into artificial bone types I-II and III-IV. Surface morphology was evaluated by Scanning Electron Microscope (SEM) and roughness parameters with Laser Scanning Confocal Microscopy (LSCM) before and after insertion (AI).

Effect of a vinegar-hydrogen peroxide mixture on the surface properties of a cobalt-chromium alloy: A possible disinfectant for removable partial dentures.

Statement Of Problem: A vinegar-hydrogen peroxide mixture has been reported to be effective in eliminating Candida albicans and Staphylococcus aureus from acrylic resin, and its action has been reported to be comparable with that of sodium hypochlorite or peracetic acid. However, the effects of this mixture on cobalt-chromium alloys remain unknown.

Purpose: The purpose of this in vitro study was to evaluate the surface roughness, Knoop microhardness, surface free energy, and wettability of a cobalt-chromium alloy when exposed to a vinegar-hydrogen peroxide mixture.

Does implant surface hydrophilicity influence the maintenance of surface integrity after insertion into low-density artificial bone?

Objective: To evaluate the influence of hydrophilicity on the surface integrity of implants after insertion in low-density artificial bone and to determine the distribution of titanium (Ti) particles along the bone bed.

Methods: Forty-eight dental implants with different designs (Titamax Ex, Facility, Alvim, and Drive) and surface treatments (Neoporos® and Aqua™) were inserted into artificial bone blocks with density compatible with bone type III-IV. Hydrophobic Neoporos® surfaces were obtained by sandblasting and acid etching while hydrophilic Aqua™ surfaces were obtained by sandblasting, acid etching, and storage in an isotonic 0.

Glucose effect on Candida albicans biofilm during tissue invasion.

Objective: To evaluate, in vitro, the effect of two glucose concentrations (0.1 mM and 1.0 mM, simulating glucose concentration in saliva of healthy and diabetic individuals) on Candida albicans biofilm grown on epithelial monolayer.

Effect of Vehicle and Agitation Methods on the Penetration of Calcium Hydroxide Paste in the Dentinal Tubules.

Introduction: The aim of this ex vivo study was to analyze the effect of different vehicles combined with agitation methods on the penetration of calcium hydroxide (CH) paste in the dentinal tubules.

Methods: Sixty freshly extracted, single-rooted human premolars were prepared using WaveOne Gold (Dentsply Sirona, York, PA) and randomized into 6 experimental groups (n = 10) according to the vehicle and method of paste agitation as follows: propylene glycol (PG) + Lentulo, PG + Lentulo + ultrasound, PG + Lentulo + sonic, distilled water (DW) + Lentulo, DW + Lentulo + ultrasonic, and DW + Lentulo + sonic. The CH paste was manipulated with sodium fluorescein dye and was inserted to completely fill the root canal.

In situ analysis of gelatinolytic activity in human dentin.

Matrix metalloproteinases (MMPs) such as gelatinases are differentially expressed in human tissues. These enzymes cleave specific substrates involved in cell signaling, tissue development and remodeling and tissue breakdown. Recent evidences show that gelatinases are crucial for normal dentin development and their activity is maintained throughout the entire tooth function in the oral cavity.

Biomechanical Behavior of the Dental Implant Macrodesign.

Purpose: The aim of this study was to evaluate the influence of implant macrodesign when using different types of collar and thread designs on stress/strain distributions in a maxillary bone site.

Materials And Methods: Six groups were obtained from the combination of two collar designs (smooth and microthread) and three thread shapes (square, trapezoidal, and triangular) in external hexagon implants (4 × 10 mm) supporting a single zirconia crown in the maxillary first molar region. A 200-N axial occlusal load was applied to the crown, and measurements were made of the von Mises stress (σ) for the implant, and tensile stress (σ), shear stress (τ), and strain (ε) for the surrounding bone using tridimensional finite element analysis.

Short implants to support mandibular complete dentures - photoelastic analysis.

This study evaluated the stress behavior around short implants in edentulous atrophic mandibles. Six groups included implants with two diameters regular and wide (4 and 5 mm) and three lengths (5, 7 and 9 mm) as follows: Ci9 (9 x 4 mm), Ci7 (7 x 4 mm), Ci5 (5 x 4 mm), Wi9 (9 x 5 mm), Wi7 (7 x 5 mm) and Wi5 (5 x 5 mm). These groups were compared to the control group CG (11 x 4 mm).

Prosthetic abutment influences bone biomechanical behavior of immediately loaded implants.

This study aimed to evaluate the influence of the type of prosthetic abutment associated to different implant connection on bone biomechanical behavior of immediately and delayed loaded implants. Computed tomography-based finite element models comprising a mandible with a single molar implant were created with different types of prosthetic abutment (UCLA or conical), implant connection (external hexagon, EH or internal hexagon, IH), and occlusal loading (axial or oblique), for both immediately and delayed loaded implants. Analysis of variance at 95%CI was used to evaluate the peak maximum principal stress and strain in bone after applying a 100 N occlusal load.

The role of prosthetic abutment material on the stress distribution in a maxillary single implant-supported fixed prosthesis.

Purpose: Evaluate the influence of abutment's material and geometry on stress distribution in a single implant-supported prosthesis.

Materials And Methods: Three-dimensional models were made based on tomographic slices of the upper middle incisor area, in which a morse taper implant was positioned and a titanium (Ti) or zirconia (ZrN) universal abutments was installed. The commercially available geometry of titanium (T) and zirconia (Z) abutments were used to draw two models, TM1 and ZM1 respectively, which served as control groups.

Salivary pellicles equalise surfaces' charges and modulate the virulence of Candida albicans biofilm.

Introduction: Numerous environmental factors influence the pathogenesis of Candida biofilms and an understanding of these is necessary for appropriate clinical management.

Aims: To investigate the role of material type, pellicle and stage of biofilm development on the viability, bioactivity, virulence and structure of C. albicans biofilms.

Modulation of Candida albicans virulence by bacterial biofilms on titanium surfaces.

Whilst Candida albicans occurs in peri-implant biofilms, its role in peri-implantitis remains unclear. This study therefore examined the virulence of C. albicans in mixed-species biofilms on titanium surfaces.

Effects of acids used in the microabrasion technique: Microhardness and confocal microscopy analysis.

Background: This study evaluated the effects of the acids used in the microabrasion on enamel.

Material And Methods: Seventy enamel/dentine blocks (25 mm2) of bovine incisors were divided into 7 groups (n=10). Experimental groups were treated by active/passive application of 35% H3PO4 (E1/E2) or 6.

Effect of Collagen Matrix Saturation on the Surface Free Energy of Dentin using Different Agents.

Introduction: The surface free energy of conditioned-dentin is one of the factors that interfere with monomeric infiltration of the interfibrillar spaces. Saturation of the tooth matrix with different substances may modulate this energy and, consequently, the wettability of the dentin.

Aim: To evaluate the influence of different substances used to saturate conditioned-dentin on surface free energy (SFE) of this substrate.

Biofilm and saliva affect the biomechanical behavior of dental implants.

Friction coefficient (FC) was quantified between titanium-titanium (Ti-Ti) and titanium-zirconia (Ti-Zr), materials commonly used as abutment and implants, in the presence of a multispecies biofilm (Bf) or salivary pellicle (Pel). Furthermore, FC was used as a parameter to evaluate the biomechanical behavior of a single implant-supported restoration. Interface between Ti-Ti and Ti-Zr without Pel or Bf was used as control (Ctrl).

Virulence and pathogenicity of Candida albicans is enhanced in biofilms containing oral bacteria.

This study examined the influence of bacteria on the virulence and pathogenicity of candidal biofilms. Mature biofilms (Candida albicans-only, bacteria-only, C. albicans with bacteria) were generated on acrylic and either analysed directly, or used to infect a reconstituted human oral epithelium (RHOE).