Effect of In Situ Acid Erosion on Structural and Optical Properties of Nanoparticulated Bisacrylic Resin With Different Surface Treatments.

Objective: To evaluate the influence of in situ acid erosion on the structural and optical properties of nanoparticulate bisacrylic resin with different surface treatments, evaluating surface roughness (Ra), knoop microhardness (KHN), color change (ΔE, ΔL, ΔC, ΔH), contrast (CR) and translucency (TP).

Methods: Eighty specimens were made (n = 10 per group) and the following surface treatments were applied: U-unpolished; A-polishing with Astropol rubber tips (Ivoclar); S-Biscover LV surface sealant (Bisco) and S-Palaseal surface sealant (kulzer). For the in situ experiment, 10 volunteers wore an intraoral appliance containing eight specimens (two specimens per experimental group), with only one specimen from each experimental group being subjected to the acid process.

Comparison of mechanical properties of 3D printer resins for occlusal splints using different models of 3D printers.

Background: Considering the development of new 3D printing technologies that use different printing techniques, further studies must be conducted to evaluate the impact of different printing systems on the mechanical properties of 3D-printed materials. This study aimed to evaluate the mechanical properties of 3D-printed materials for occlusal devices using different 3D printers and printing layer thicknesses.

Material And Methods: Ninety rectangular samples were manufactured and divided into nine groups according to the 3D printer model they were printed on (AnyCubic Mono X, Elegoo Mars 2, or FlashForge Hunter) and the layer thickness (20, 50, or 100 µm) and were subjected to superficial microhardness, flexural resistance, and elasticity modulus tests.

Influence of ceramic crown design (translucent monolithic zirconia vs. bilayered) of implant-supported single crowns after mechanical cycling.

Objectives: This study aimed to assess the influence of translucent monolithic versus bilayered crowns and whether the use of a CoCr base abutments affects the fatigue and fracture resistance of screwed implant-supported single crowns with external connections under mechanical cycling.

Materials And Methods: Fifty specimens were divided into groups: (1) metal-ceramic (MC) crown, (2) veneered zirconia crown (Zr), (3) veneered zirconia crown with a CoCr base abutment (ZrB), (4) monolithic translucent zirconia crown (MZr), and (5) monolithic translucent zirconia crown with a CoCr base abutment (MZrB). Specimens underwent mechanical cycling (5 × 10 cycles; 150 N) evaluating fatigue resistance (number of failures) and those that failed were subsequently subjected to fractographic analyses (stereomicroscope and scanning electron microscope) to evaluate failure location and area, and maximum fracture load was also measured.

Color stability and surface roughness of resin-ceramics with different surface treatments: A systematic review and meta-analysis of in vitro studies.

Statement Of Problem: Surface treatments for resin-ceramics have been developed to obtain a smooth surface and improve color stability. However, a consensus on the best treatment for these materials is lacking.

Purpose: The purpose of this systematic review and meta-analysis was to evaluate the color stability and roughness of glass-ceramics versus resin-ceramics with different surface treatments.

Polyetheretherketone materials for removable partial denture frameworks: an integrative review.

Polyetheretherketone (PEEK) resin is a high-performance thermoplastic polymer that has been introduced as a possible candidate to replace metallic components in dental prostheses. The objective of this integrative review was to compare, through analysis of studies in the literature, the mechanical performance of removable partial denture frameworks and clasps manufactured with PEEK with the performance of cobalt-chromium (Co-Cr) frameworks and clasps. The guiding question was, "Does the use of PEEK as a substitute for Co-Cr alloys for the construction of removable partial denture frameworks result in better mechanical properties?" The PubMed/ MEDLINE, Embase, Web of Science, Scopus, and SciELO databases were searched for articles published through October 2021.

Evaluation of the mechanical properties of different materials for manufacturing occlusal splints.

This study aimed to compare the mechanical properties of various occlusal plate materials by analyzing surface roughness, Knoop microhardness, flexural strength, and modulus of elasticity. Fifty samples were prepared and classified as SC (self-curing acrylic resin), WB (heat-cured acrylic resin), ME (acrylic resin polymerized by microwave energy), P (resin print), and M (polymethylmethacrylate polymer block for computer-aided design/computer-aided manufacturing). The data were analyzed using a one-way analysis of variance and Tukey's honestly significant difference test.

Evaluation of bond strength of glass and resin-ceramics with laser phototherapy: A systematic review and meta-analysis of in vitro studies.

Statement Of Problem: Laser phototherapy has been studied as a surface treatment capable of increasing the adhesion of cement to the ceramic surface. However, the bond strength of glass and resin-ceramics after laser phototherapy is unclear.

Purpose: The objective of this systematic review and meta-analysis was to compare the bond strength of glass and resin-ceramics using laser therapy and conventional hydrofluoric acid etching.

Silica deposition on zirconia via room-temperature atomic layer deposition (RT-ALD): Effect on bond strength to veneering ceramic.

Purpose: To develop and to characterize a hybrid interface between yttria-stabilized zirconia (Y-TZP) transformed layer and silica-based nanofilm to enable a better bonding between Y-TZP and a veneering ceramic.

Material And Methods: Sixty-six fully-sintered rectangular Y-TZP specimens were distributed into 6 groups, according to the surface treatment applied: C (control): no treatment; Al: 27 μm-alumina particle abrasion; Ht: hydrothermal treatment in autoclave for 15h; Si20: 20 cycles of silica deposition using room-temperature atomic layer deposition (RT-ALD); Si40: 40 cycles of RT-ALD; Ht + Si40: hydrothermal treatment followed by 40 cycles of RT-ALD. RT-ALD was performed by the sequential exposure of specimens to vapor of tetramethoxysilane orthosilicate (TMOS) and ammonium hydroxide (NHOH).

Dentistry and Intensive Care Unit: A Brief Report.

Objective:  The aim of this study is to verify whether removable dentures of patients admitted to an intensive care unit (ICU) are niches of microorganisms that can cause pathologies (, , and enterobacteria).

Materials And Methods:  Fifteen patients who were denture wearers (removable partial denture and complete denture) were included in this study. Patients must wear their dentures daily, and these dentures must have acrylic parts.

Surface characterization of different surface treatments associations with plasma and bonding analysis of Y-TZP and the veneering ceramic.

Objectives: To characterize the surface of zirconia (Y-TZP) submitted to different surface treatments (with and without plasma associations) and to evaluate the shear bond strength (SBS) between veneering ceramic (VC) and Y-TZP after different aging methods.

Methods: 301 Y-TZP specimens were fabricated and distributed into 7 groups: C (control): no treatment; Al: airborne abrasion with 27 μm AlO particle; L: liner; P: plasma; Al + L: airborne + liner; Al + P: airborne + plasma; P + L: plasma + liner. The Y-TZP surface was characterized by SEM, EDS, AFM, surface profilometry, surface-free energy (SFE), and XRD.

Effect of laser irradiation on bond strength between zirconia and resin cement or veneer ceramic: A systematic review and meta-analysis.

Aim: This systematic review with meta-analysis aimed to evaluate the effect of the laser treatment on bond strength between Y-TZP and the resin cement or with the veneering ceramic, and the effect on the alteration of the Y-TZP surface roughness.

Settings And Design: Systematic review and meta analysis following PROSPERO guidelines.

Materials And Methods: A comprehensive review was performed up to September 2020 on four databases (PubMed/MEDLINE, Embase, Scopus, and Cochrane Library), using the combination of keywords: "laser AND zirconia AND surface treatment AND bond strength".

Survival and complications of monolithic ceramic for tooth-supported fixed dental prostheses: A systematic review and meta-analysis.

Statement Of Problem: Although recent studies have reported the success of implant-supported monolithic restorations, consensus on the use of monolithic ceramic restorations is lacking.

Purpose: The purpose of this systematic review and meta-analysis was to evaluate the survival and biological and technical complication rates of monolithic single crowns and fixed partial dentures (FPDs).

Material And Methods: An electronic search was conducted by 2 independent authors on the PubMed/MEDLINE, Scopus, and Cochrane Library databases.

Effect of handling material on mechanical and optical properties of feldspathic porcelain.

Objective: To evaluate the optical, chemical, and mechanical properties of feldspathic porcelain after handling with different instrument materials.

Material And Methods: Feldspathic porcelain was manipulated with different spatula compositions: metal spatula (MS), plastic spatula (PS), and glass spatula (GS) for the fabrication of 30 (n = 10) disks. Contrast ratio (CR), translucency parameter (TP), and surface Knoop microhardness (KHN) were measured.

Influence of Different Pigmentations and Accelerated Aging on the Hardness and Tear Strength of the A-2186 and MDX4-4210 Silicones.

Objective: To evaluate the influence of different pigmentations and accelerated aging on the hardness and tear strength of the A-2186 and MDX4-4210 silicones.

Materials And Methods: The samples A-2186 and MDX4-4210 were manufactured without and with pigmentations (black, bronze, and pink). For the Shore A hardness test, 80 samples of each silicone were fabricated, and for the tear strength test, 320 samples of each silicone were fabricated.

Cytotoxicity and inflammatory response of different types of provisional restorative materials.

Aim: To evaluate the cytotoxicity and inflammatory response of different types of provisional restorative materials to mice gingival fibroblasts.

Methods: Cytotoxicity of provisional material discs (thermal-polymerized acrylic resin; auto-polymerized acrylic resin; bisacrylic resin; nano-ceramic resin for CAD/CAM and prefabricated polymer block for CAD/CAM) to Mice (Balb/c) gingival cell were investigated under direct and indirect contact (extracts) at 24, 48 and 72 h, using the MTT and Alamar blue assays. Materials extracts (24 h) were applied to the cell culture (indirect contact) or cells were seeded on discs of provisional materials, and the cytotoxicity and production of IL-6, IL-1β and TNF-α after 24, 48 and 72 h were analyzed through MTT, Alamar Blue® and ELISA.

Long-term stainability of interim prosthetic materials in acidic/staining solutions.

Objective: To evaluate the long-term color stainability, translucency, and contrast ratio (CR) of different resins used to fabricate interim prostheses after immersion in acidic/staining solutions.

Materials And Methods: A total of 160 specimens were divided into 16 groups (n = 10) according to the material (heat-polymerized acrylic resin [HPAR], auto-polymerized acrylic resin [APR], nanoparticulated bis-acrylic resin [BR], and prefabricated poly(methyl methacrylate) block for CAD/CAM [CADR]) and immersion solutions (artificial saliva, cola beverage, coffee, and red wine). A spectrophotometer was used before and after each immersion period (7, 14, 28, 90, and 180 days).

Stress distribution of different implant connections associated with multiple implant-supported prostheses.

In some clinical situations, the clinician may encounter previously installed implants that should be associated with other implants for a proper rehabilitation. The aim of this study was to evaluate the biomechanical behaviour of a multiple prosthesis joined by different implant connections using photoelasticity. Photoelastic models with a screwed fixed prosthesis supported by implants with different connection systems (Morse taper, external hexagon, internal hexagon, and Flexcone), and different combinations among them, were fabricated.

Characterisation of a new plasma-enhanced film to improve shear bond strength between zirconia and veneering ceramic.

The aim of this study was to develop and characterise a new plasma-enhanced chemical vapor deposition (PECVD) film for improving shear bond strength (SBS) between yttria-stabilised tetragonal zirconia (Y-TZP) and veneering ceramic. In total, 192 Y-TZP samples (13 × 5.4 × 5 mm) were divided into 6 groups: control - no treatment (C), airborne-particle abrasion with 27 μm aluminum oxide particles (Al), 110 μm aluminum oxide particles (Al), and 250 μm aluminum oxide particles (Al), application of liner for zirconia (L) and the PECVD film application (P).

The Effect of Surface Treatment on Shear Bond Strength between Y-TZP and Veneer Ceramic: A Systematic Review and Meta-Analysis.

Purpose: The objective of this systematic review with meta-analysis was to evaluate surface treatment in yttria-stabilized tetragonal zirconia polycrystal ceramic (Y-TZP) on the shear bond strength (SBS) values between Y-TZP (core ceramic) and veneer ceramic, compared to untreated specimens.

Materials And Methods: This review was registered at PROSPERO platform under the number CRD42016036493. The systematic review of the extracted publications was performed to compare the effect of surface treatment on SBS between Y-TZP ceramic and veneering ceramic.

Stress Distribution in an Implant-Supported Mandibular Complete Denture Using Different Cantilever Lengths and Occlusal Coating Materials.

Purpose: The aim of this study was to assess stress distribution in the bone-implant interface of a mandibular implant-supported prosthesis with different cantilever lengths, aesthetic coating materials, and implant abutments.

Materials And Methods: A photoelastic model of an edentulous mandible, containing 5 external hexagon implants, was constructed. Experimental models were divided into 6 groups: group 1-UCLA component and metal bar; group 2-UCLA component and acrylic resin coating; group 3-UCLA component and porcelain coating; group 4-abutment and metal bar; group 5-abutment and acrylic resin coating; and group 6-abutment and porcelain coating.

Surface characterization of polymers used in fabrication of interim prostheses after treatment with photopolymerized glaze.

The material used for interim prostheses fabrication must present excellent physical properties for greater longevity in the face of environmental conditions, which can occur in the oral cavity. The purpose of this study was to evaluate the effect of a photopolymerized glaze on the physical and mechanical properties of polymers used for the fabrication of interim prostheses, before and after thermocycling and immersion in staining solutions. One hundred samples of composite and acrylic resins were fabricated: Dencor chemically activated acrylic resin (CAAR) (n=20) and heat-polymerized acrylic resin (HPAR) (n=20), Charisma (n=20), Structur (n=20), and Protemp (n=20).

A photoelastic and strain gauge comparison of two attachments for obturator prostheses.

Statement Of Problem: The rehabilitation of patients after a maxillectomy involves the use of an obturator to seal oral-nasal-sinus communication and to facilitate mastication, swallowing, and speech.

Purpose: The purpose of this in vitro study was to evaluate different attachment systems used for implant-retained obturators at dissipation loads and under shear forces.

Material And Methods: Photoelastic models were fabricated with 3 external hexagon implants at the incisor, canine, and first molar regions.

Stress distribution on short implants with different designs: a photoelastic analysis.

Short dental implants have been used as an attempt to avoid bone grafts surgery, however there are few literature reports that evaluate changes to their design. Therefore, the aim of this study was to assess the effect of different short implant design on stress distribution through photoelastic analysis. Six external hexagon (5 × 5 mm) short dental implants with different design were used.

Are Zirconia Implant Abutments Safe and Predictable in Posterior Regions? A Systematic Review and Meta-Analysis.

Purpose: This systematic review aimed to evaluate whether the survival rate and predictability of zirconia abutments are similar to those of titanium abutments for single implant crowns in the posterior area.

Materials And Methods: A systematic search of two databases (Medline/PubMed and Cochrane Library) was performed by two independent reviewers for articles published between January 2004 and July 2014. The electronic search was complemented by a hand search of the following journals from the same period: Journal of Periodontology, Clinical Oral Implants Research, International Journal of Prosthodontics, and International Journal of Oral and Maxillofacial Implants.

Stress distribution in implant-supported prostheses using different connection systems and cantilever lengths: digital photoelasticity.

Photoelastic analysis was used to evaluate the biomechanical behaviour of implant-supported, double-screwed crowns with different connection systems and cantilever lengths. Three models were made in PL-2 photoelastic resin and divided into six groups, on the basis of the implant connection system (external hexagon [EH] or Morse taper [MT]), type of abutment (Mini Pilar [Neodent, Curitiba, Paraná, Brazil] or "UCLA") and number of crowns in the cantilever (one or two). The implant-prosthesis unit was placed in a circular polariscope.