A computer-assisted endodontic access technique to remove fiber posts.

Clinical treatments employing a 3-dimensional computer-assisted endodontic access technique (CEAT-3D) to remove fiber posts from posterior teeth in a minimally invasive manner using computer-aided design and computer-aided manufacturing (CAD-CAM) technology are described. Three patients with symptomatic molars and periapical radiolucency and with different treatment complexities had been referred for endodontic retreatment. For the removal of the fiber posts and endodontic retreatment, 3-dimensionally printed guides were designed from intraoral and cone beam computed tomography (CBCT) scans with a digital planning software program.

Expanding the Application of Digital Dentistry with 3D Patient Monitoring.

Intraoral scanners have been used to capture data for the design and subsequent manufacture of dental restorations and also for registering color clinical images. Scanners can capture datasets for future use and comparisons. This manuscript describes the potential of using software algorithms to superimpose 3D images captured at different times to calculate dimensional changes at the click of a button in various dental fields.

Complete denture digital workflow: Combining basic principles with a CAD-CAM approach.

This report describes a digital workflow for the fabrication of a complete maxillary denture opposing an implant-retained overdenture. This procedure provides a predictable and accurate 3-visit technique to digitally scan and articulate edentulous ridges, avoiding the discomfort associated with analog impression making. Wax rims were applied to intraorally relined plastic edentulous stock trays.

A new species of Paratelmatobius (Anura: Leptodactylidae: Paratelmatobiinae) from the Atlantic Forest of southern Brazil.

A new species of Paratelmatobius is described from the Brazilian Atlantic Forest in the state of Paraná in southern Brazil. Adults, tadpoles, and vocalizations are described. Morphological traits and phylogenetic analysis place the new species within the P.

Reliability and Failure Modes of a Hybrid Ceramic Abutment Prototype.

Purpose: A ceramic and metal abutment prototype was fatigue tested to determine the probability of survival at various loads.

Materials And Methods: Lithium disilicate CAD-milled abutments (n = 24) were cemented to titanium sleeve inserts and then screw attached to titanium fixtures. The assembly was then embedded at a 30° angle in polymethylmethacrylate.

Mini fiberglass post for composite resin restorations: A clinical report.

Threaded metal pins have been used to create additional retention for large composite resin restorations. However, their dark appearance may compromise esthetic outcome. The use of small fiberglass posts has been advocated as an alternative.

A new classification system for all-ceramic and ceramic-like restorative materials.

Classification systems for all-ceramic materials are useful for communication and educational purposes and warrant continuous revisions and updates to incorporate new materials. This article proposes a classification system for ceramic and ceramic-like restorative materials in an attempt to systematize and include a new class of materials. This new classification system categorizes ceramic restorative materials into three families: (1) glass-matrix ceramics, (2) polycrystalline ceramics, and (3) resin-matrix ceramics.

Reliability and failure modes of two Y-TZP abutment designs.

Fracture strength and accelerated fatigue reliability of two zirconia abutment systems were tested. Thirty-six implants with a Morse taper (MT; n = 18) or cone (C; n = 18) design were restored with metallic crowns. Loads were applied as single load to failure (SLF) or mouth-motion cycles using a step-stress accelerated life testing (SALT) method.

Slow cooling protocol improves fatigue life of zirconia crowns.

Objective: To compare the fatigue life and damage modes of zirconia crowns fabricated with and without framework design modification when porcelain veneered using a fast or slow cooling protocol.

Methods: Composite resin replicas of a first molar full crown preparation were fabricated. Zirconia copings were milled as conventional (0.

Influence of abutment-to-fixture design on reliability and failure mode of all-ceramic crown systems.

Objective: Evaluate the effect of implant connection designs on reliability and failure modes of screw-retained all-ceramic crowns.

Methods: Central incisor ceramic crowns in zirconia abutments were screwed and torqued down to external hexagon (EH), internal hexagon (IH) and Morse taper (MT) implant systems. Single-load-to-fracture (SLF) test (n=4 per group) determined three step-stress fatigue profiles with specimens assigned in the ratio of 3:2:1.

MicroCT analysis of a retrieved root restored with a bonded fiber-reinforced composite dowel: a pilot study.

Purpose: This evaluation aimed to (1) validate micro-computed tomography (microCT) findings using scanning electron microscopy (SEM) imaging, and (2) quantify the volume of voids and the bonded surface area resulting from fiber-reinforced composite (FRC) dowel cementation technique using microCT scanning technology/3D reconstructing software.

Materials And Methods: A fiberglass dowel was cemented in a condemned maxillary lateral incisor prior to its extraction. A microCT scan was performed of the extracted tooth creating a large volume of data in DICOM format.

Low temperature degradation and reliability of one-piece ceramic oral implants with a porous surface.

Unlabelled: Low temperature degradation of zirconia (3Y-TZP) oral implants and its effect on fatigue reliability is poorly documented.

Objective: The aim of this investigation was to follow the aging process occurring at the surface of implants exhibiting a porous coating and to assess its influence on their mechanical (fatigue) properties.

Methods: Tetragonal to monoclinic transformation (t-m) was evaluated during accelerated aging tests up to 100h in autoclave (134°C, 2 bars) by X-ray diffraction (XRD) and focused ion beam (FIB).

Mechanical testing of implant-supported anterior crowns with different implant/abutment connections.

Purpose: This study evaluated the reliability and failure modes of anterior implants with internal-hexagon (IH), external-hexagon (EH), or Morse taper (MT) implant-abutment interface designs. The postulated hypothesis was that the different implant-abutment connections would result in different reliability and failure modes when subjected to step-stress accelerated life testing (SSALT) in water.

Materials And Methods: Sixty-three dental implants (4 × 10 mm) were divided into three groups (n = 21 each) according to connection type: EH, IH, or MT.

Effect of core design and veneering technique on damage and reliability of Y-TZP-supported crowns.

Objectives: To evaluate the effect of framework design modification and veneering techniques in fatigue reliability and failure modes of veneered Yttria-Stabilized Tetragonal Zirconia Polycrystals (Y-TZP) crowns.

Methods: A CAD-based mandibular molar crown preparation served as a master die. Y-TZP crown cores (VITA-In-Ceram-YZ, Vita-Zahnfabrik, Bad Säckingen, Germany) in conventional (0.

Mechanical, biological and clinical aspects of zirconia implants.

The objective of this narrative overview is to discuss several in vitro and in vivo studies regarding the performance of one-piece zirconia implants in combination with the description of two clinical scenarios where zirconia implant prototypes were utilized with emphasis on the possible scientific and clinical concerns that may affect the functional, biological and esthetic long-term outcomes.

Surface characterisation and bonding of Y-TZP following non-thermal plasma treatment.

Objectives: (1) To chemically characterise Y-TZP surface via X-ray photoelectron spectroscopy (XPS) and evaluate the surface energy levels (SE) after non-thermal plasma (NTP). (2) To test the microtensile bond strength (MTBS) of Y-TZP bonded to cured composite disks, after a combination of different surface conditioning methods.

Methods: Twenty-four Y-TZP discs (13.

Reliability evaluation of alumina-blasted/acid-etched versus laser-sintered dental implants.

Step-stress accelerated life testing (SSALT) and fractographic analysis were performed to evaluate the reliability and failure modes of dental implant fabricated by machining (surface treated with alumina blasting/acid etching) or laser sintering for anterior single-unit replacements. Forty-two dental implants (3.75 × 10 mm) were divided in two groups (n=21 each): laser sintered (LS) and alumina blasting/acid etching (AB/AE).

Osseointegration assessment of chairside argon-based nonthermal plasma-treated Ca-P coated dental implants.

This study investigated the effect of an Argon-based nonthermal plasma (NTP) surface treatment-operated chairside at atmospheric pressure conditions applied immediately prior to dental implant placement in a canine model. Surfaces investigated comprised: Calcium-Phosphate (CaP) and CaP + NTP (CaP-Plasma). Surface energy was characterized by the Owens-Wendt-Rabel-Kaelble method and chemistry by X-ray photoelectron spectroscopy (XPS).

Biomechanical evaluation of internal and external hexagon platform switched implant-abutment connections: An in vitro laboratory and three-dimensional finite element analysis.

Objectives: The aim of this study was to assess the effect of abutment's diameter shifting on reliability and stress distribution within the implant-abutment connection for internal and external hexagon implants. The postulated hypothesis was that platform-switched implants would result in increased stress concentration within the implant-abutment connection, leading to the systems' lower reliability.

Methods: Eighty-four implants were divided in four groups (n=21): REG-EH and SWT-EH (regular and switched-platform implants with external connection, respectively); REG-IH and SWT-IH (regular and switched-platform implants with internal connection, respectively).

Residual thermal stress simulation in three-dimensional molar crown systems: a finite element analysis.

Purpose: To simulate coefficient of thermal expansion (CTE)-generated stress fields in monolithic metal and ceramic crowns, and CTE mismatch stresses between metal, alumina, or zirconia cores and veneer layered crowns when cooled from high temperature processing.

Materials And Methods: A 3D computer-aided design model of a mandibular first molar crown was generated. Tooth preparation comprised reduction of proximal walls by 1.

Conventional and modified veneered zirconia vs. metalloceramic: fatigue and finite element analysis.

Purpose: The purpose of this study was to test the hypothesis that all-ceramic crown core-veneer system reliability is improved by modifying the core design and as a result is comparable in reliability to metal-ceramic retainers (MCR). Finite element analysis (FEA) was performed to verify maximum principal stress distribution in the systems.

Materials And Methods: A first lower molar full crown preparation was modeled by reducing the height of proximal walls by 1.

Assessment of a chair-side argon-based non-thermal plasma treatment on the surface characteristics and integration of dental implants with textured surfaces.

The biomechanical effects of a non-thermal plasma (NTP) treatment, suitable for use in a dental office, on the surface character and integration of a textured dental implant surface in a beagle dog model were evaluated. The experiment compared a control treatment, which presented an alumina-blasted/acid-etched (AB/AE) surface, to two experimental treatments, in which the same AB/AE surface also received NTP treatment for a period of 20 or 60 s per implant quadrant (PLASMA 20' and PLASMA 60' groups, respectively). The surface of each specimen was characterized by electron microscopy and optical interferometry, and surface energy and surface chemistry were determined prior to and after plasma treatment.

Argon-based atmospheric pressure plasma enhances early bone response to rough titanium surfaces.

This study investigated the effect of an Argon-based atmospheric pressure plasma (APP) surface treatment operated chairside at atmospheric pressure conditions applied immediately prior to dental implant placement in a canine model. Surfaces investigated comprised: rough titanium surface (Ti) and rough titanium surface + Argon-based APP (Ti-Plasma). Surface energy was characterized by the Owens-Wendt-Rabel-Kaelble method and chemistry by X-ray photoelectron spectroscopy (XPS).

Reliability and failure modes of internal conical dental implant connections.

Objective: Biological and mechanical implant-abutment connection complications and failures are still present in clinical practice, frequently compromising oral function. The purpose of this study was to evaluate the reliability and failure modes of anterior single-unit restorations in internal conical interface (ICI) implants using step-stress accelerated life testing (SSALT).

Materials And Methods: Forty-two ICI implants were distributed in two groups (n = 21 each): group AT-OsseoSpeed(™) TX (Astra Tech, Waltham, MA, USA); group SV-Duocon System Line, Morse Taper (Signo Vinces Ltda.

Effect of microthread presence and restoration design (screw versus cemented) in dental implant reliability and failure modes.

Objectives: This study evaluated the reliability and failure modes of implants with a microthreaded or smooth design at the crestal region, restored with screwed or cemented crowns. The postulated null hypothesis was that the presence of microthreads in the implant cervical region would not result in different reliability and strength to failure than smooth design, regardless of fixation method, when subjected to step-stress accelerated life-testing (SSALT) in water.

Materials And Methods: Eighty four dental implants (3.