Biomechanical performance of three fiberglass post cementation techniques: Imaging, in vitro, and in silico analysis.

Purpose: The structural integrity of the resin cement layer, the bond strength, and the biomechanical behavior of different fiberglass post cementation techniques were evaluated.

Methods: Thirty-three bovine incisors were divided into three groups (n = 11): conventional fiberglass post (CFP), conventional fiberglass post in flared root canals (CFL), and relined fiberglass post (RFP). Six specimens from each group were submitted for high-resolution microcomputed tomography (μCT) to evaluate the integrity and presence/volume of voids at the resin cement layer.

An alternative 2-step cementation technique to reduce polymerization shrinkage stress in root canals: a case report.

The functional rehabilitation of teeth with endodontic involvement and substantial loss of coronal structure can be a challenging scenario. The use of fiber-reinforced posts (FRPs) promotes retention and supports the restoration. The main cause of failure associated with the use of FRPs is the debonding of the post, mainly due to polymerization contraction or incorporation of voids in the thick resin cement layer during the cementation protocol.

Influence of resin cement thickness and temperature variation on mechanical behavior of dental ceramic fragment restoration.

To evaluate the stress behavior of ceramic fragment restoration, varying the thickness of the cement layer and intraoral temperature variation. A solid model of a upper lateral incisor was obtained and a defect at enamel distal/incisal edge was restored with a ceramic fragment. Based on this initial model, 4 different models (M) were built: M1 - absence of cement layer (CL) (0 μm of thickness); M2 - CL with an uniform thickness of 50 μm; M3 - CL with 50 μm at the margin of ceramics and 100 μm in the inner area far from margins; M4 - CL with 50 μm at the margin of ceramics and 200 μm in the inner area far from margins.

Minimally Invasive Ceramic Restorations: A Step-by-Step Clinical Approach.

Minimally invasive treatments are a dominant trend in dentistry. Due to the evolution of adhesive materials and ceramics, minimalistic ceramic restorations have been proposed as alternative treatment options to avoid unnecessary tooth reduction. The aim of this article is to show a clinical protocol for the correct diagnosis, treatment planning, and execution of minimally invasive ceramic veneers.

Nanomechanical Assessment of Bone Surrounding Implants Loaded for 3 Years in a Canine Experimental Model.

Purpose: This work evaluated the nanomechanical properties of bone surrounding submerged and immediately loaded implants after 3 years in vivo. It was hypothesized that the nanomechanical properties of bone would markedly increase in immediately and functionally loaded implants compared with submerged implants.

Materials And Methods: The second, third, and fourth right premolars and the first molar of 10 adult Doberman dogs were extracted.

Sealing the Screw Access Channel with Polytetrafluoroethylene Tape: Advantages of the Technique.

The aim of this article is to describe the procedure for sealing the screw access channel using plastic tape, polytetrafluoroethylene, in screw- or cement-retained implant-supported prostheses. This technique is viable and easily performed, and the functional and esthetic results are satisfactory.

In Silico Analysis of the Biomechanical Stability of Commercially Pure Ti and Ti-15Mo Plates for the Treatment of Mandibular Angle Fracture.

Purpose: To investigate the influence of different materials and fixation methods on maximum principal stress (MPS) and displacement in reconstruction plates using in silico 3-dimensional finite element analysis (3D-FEA).

Materials And Methods: Computer-assisted designed (CAD) models of the mandible and teeth were constructed. Champy and AO/ASIF plates and fixation screws were designed with CAD software.

Effect of time and ultrasonic activation on ethylenediaminetetraacetic acid on smear layer removal of the root canal.

The aim of this study was to assess the effect of time and the ultrasonic activation of ethylenediaminetetraacetic acid (EDTA) in removing the smear layer of at root canal. A total of 60 bovine inferior incisors were transversely sectioned and instrumented; A smear layer was added in the root dentin surface. The specimen were then divided into six groups according to the following final irrigation protocols: Group (G) 1: conventional irrigation with sodium hypochlorite (NaOCl); G2: conventional irrigation with NaOCl + EDTA for 20 s; G3: conventional irrigation with NaOCl + EDTA for 60 s; G4: passive ultrasonic irrigation (PUI) with NaOCl; G5: PUI with NaOCl + PUI with EDTA for 20 s; G6: PUI + NaOCl and PUI with EDTA for 60 s.

Survival and failure modes: platform-switching for internal and external hexagon cemented fixed dental prostheses.

This study evaluated the probability of survival (reliability) of platform-switched fixed dental prostheses (FDPs) cemented on different implant-abutment connection designs. Eighty-four-three-unit FDPs (molar pontic) were cemented on abutments connected to two implants of external or internal hexagon connection. Four groups (n = 21 each) were established: external hexagon connection and regular platform (ERC); external hexagon connection and switched platform (ESC); internal hexagon and regular platform (IRC); and internal hexagon and switched platform (ISC).

Clinical Comparison of At-Home and In-Office Dental Bleaching Procedures: A Randomized Trial of a Split-Mouth Design.

The objective of this split-mouth clinical study was to compare a combination of in-office and at-home dental bleaching with at-home bleaching alone. Two applications of in-office bleaching were performed, with one appointment per week, using 38% hydrogen peroxide. At-home bleaching was performed with or without in-office bleaching using 10% carbamide peroxide in a custom-made tray every night for 2 weeks.

Reliability and failure modes of narrow implant systems.

Objectives: Narrow implants are indicated in areas of limited bone width or when grafting is nonviable. However, the reduction of implant diameter may compromise their performance. This study evaluated the reliability of several narrow implant systems under fatigue, after restored with single-unit crowns.

Platform-Switching for Cemented Versus Screwed Fixed Dental Prostheses: Reliability and Failure Modes: An In Vitro Study.

Purpose: The aim of this study was to evaluate the probability of survival of cemented and screwed three-unit implant-supported fixed dental prostheses (ISFDP) using different implant-abutment horizontal matching configurations (regular vs switching platforms).

Methods: One hundred and sixty-eight implants with internal hexagon connection (4 mm diameter, 10 mm length, Emfils; Colosso Evolution System, Itú, SP, Brazil) were selected for this study according to the horizontal implant-abutment matching configuration (regular or switching) and retention method and divided in four groups (n = 21 per group) as follows: 1) regular platform cemented (IRC); 2) or screw-retained (IRS); 3) switched-platform cemented (ISC); or 4) screw-retained (ISS). Regular and platform-switched abutments (Colosso evolution, 4 mm and 3.

Effect of long-term storage on nanomechanical and morphological properties of dentin-adhesive interfaces.

Introduction: To evaluate the influence of storage time on the elastic modulus, micromorphology, nanoleakage, and micromechanical behavior of the dentin-adhesive interfaces of five adhesive systems (Scotchbond Multi-Purpose, Clearfil SE Bond, One Up Bond F, Adper Easy One, and Filtek LS Adhesive) after 24h (T0) and 12 months (T1).

Methods: Fifty teeth were restored and distributed according to each adhesive system (n=10). At least four specimens were obtained from each tooth.

Zirconia-based dental crown to support a removable partial denture: a three-dimensional finite element analysis using contact elements and micro-CT data.

Veneer fracture is the most common complication in zirconia-based restorations. The aim of this study was to evaluate the mechanical behavior of a zirconia-based crown in a lower canine tooth supporting removable partial denture (RPD) prosthesis, varying the bond quality of the veneer/coping interface. Microtomography (μCT) data of an extracted left lower canine were used to build the finite element model (M) varying the core material (gold core - MAu; zirconia core - MZi) and the quality of the veneer/core interface (complete bonded - MZi; incomplete bonded - MZi-NL).

The effect of osteotomy dimension on osseointegration to resorbable media-treated implants: a study in the sheep.

The drilling technique and the surface characteristics are known to influence the healing times of oral implants. The influence of osteotomy dimension on osseointegration of microroughned implant surfaces treated with resorbable blasting media was tested in an in vivo model. Ninety-six implants (ø4.

Effect of abutment screw surface treatment on reliability of implant-supported crowns.

Purpose: To evaluate and compare the reliability of implant-supported single crowns cemented onto abutments retained with coated (C) or noncoated (NC) screws and onto platform-switched abutments with coated screws.

Materials And Methods: Fifty-four implants (DT Implant 4-mm Standard Platform, Intra-Lock International) were divided into three groups (n = 18 each) as follows: matching-platform abutments secured with noncoated abutment screws (MNC); matching-platform abutments tightened with coated abutment screws (MC); and switched-platform abutments secured with coated abutment screws (SC). Screws were characterized by scanning electron microscopy and x-ray photoelectron spectroscopy (XPS).

Stress distribution on dentin-cement-post interface varying root canal and glass fiber post diameters. A three-dimensional finite element analysis based on micro-CT data.

Objective: The aim of the present study was to analyze the influence of root canal and glass fiber post diameters on the biomechanical behavior of the dentin/cement/post interface of a root-filled tooth using 3D finite element analysis.

Material And Methods: Six models were built using micro-CT imaging data and SolidWorks 2007 software, varying the root canal (C) and the glass fiber post (P) diameters: C1P1-C=1 mm and P=1 mm; C2P1-C=2 mm and P=1 mm; C2P2-C=2 mm and P=2 mm; C3P1-C=3 mm and P=1 mm; C3P2-C=3 mm and P=2 mm; and C3P3-C=3 mm and P=3 mm. The numerical analysis was conducted with ANSYS Workbench 10.

The effect of brain-derived neurotrophic factor on periodontal furcation defects.

This study aimed to observe the regenerative effect of brain-derived neurotrophic factor (BDNF) in a non-human primate furcation defect model. Class II furcation defects were created in the first and second molars of 8 non-human primates to simulate a clinical situation. The defect was filled with either, Group A: BDNF (500 µg/ml) in high-molecular weight-hyaluronic acid (HMW-HA), Group B: BDNF (50 µg/ml) in HMW-HA, Group C: HMW-HA acid only, Group D: empty defect, or Group E: BDNF (500 µg/ml) in saline.

Mineral loss and color change of enamel after bleaching and staining solutions combination.

Pigments of food and beverages could affect dental bleaching efficacy. The aim of this investigation was to evaluate color change and mineral loss of tooth enamel as well as the influence of staining solutions normally used by adolescent patients undergoing home bleaching. Initial hardness and baseline color were measured on enamel blocks.

Implant-abutment connection designs for anterior crowns: reliability and failure modes.

Objectives: To investigate the effect of implant-abutment connection types on reliability and failure modes of anterior single-unit crowns.

Methods: Fifty-four implants were divided in 3 groups (n = 18 each): external hexagon (EH), internal hexagon (IH), and Morse taper (MT) connection. Abutments were screwed to the implants, and maxillary central incisor metal crowns were cemented and subjected to step-stress accelerated life testing.

Tilted and short implants supporting fixed prosthesis in an atrophic maxilla: a 3D-FEA biomechanical evaluation.

Purpose: This study compared the biomechanical behavior of tilted long implant and vertical short implants to support fixed prosthesis in an atrophic maxilla.

Materials And Methods: The maxilla model was built based on a tomographic image of the patient. Implant models were based on micro-computer tomography imaging of implants.

Increased osseointegration effect of bone morphogenetic protein 2 on dental implants: an in vivo study.

Application of recombinant human bone morphogenetic protein 2 (rhBMP-2) to implant surfaces has been of great interest due to its osteoinductive potential. However, the optimal coating methodology has not been clarified. The objective of the study was to determine whether the application of rhBMP-2 onto plasma-sprayed hydroxyapatite implant surfaces by immersion in protein solution before implant installation would result in significantly improved bone apposition.

The effect of different surgical drilling procedures on full laser-etched microgrooves surface-treated implants: an experimental study in sheep.

Objectives: To evaluate the influence of instrumentation technique on the early osseointegration histomorphometrics and biomechanical fixation of fully laser-etched microgrooves implant surfaces in a sheep model.

Material And Methods: Six sheep were subjected to bilateral hip surgeries 3 and 6 weeks before euthanasia. A total of 48 implants (∅4.

Mechanical property assessment of bone healing around a titanium-zirconium alloy dental implant.

Background: It has been reported that titanium-zirconium alloy with 13-17% zirconium (TiZr1317) implants show higher biomechanical stability and bone area percentage relative to commercially pure titanium (cpTi) grade 4 fixtures.

Purpose: This study aimed to determine whether the higher stability for TiZr1317 implants is associated with higher mechanical properties of remodeling bone in the areas around the implants.

Materials And Methods: This study utilized 36 implants (n = 18: TiZr1317, n = 18: cpTi), which were placed in the healed ridges of the mandibular premolar and first molar of 12 mini pigs (n = 3 implants/animal).

Biomechanical evaluation of undersized drilling on implant biomechanical stability at early implantation times.

Purpose: The present study evaluated the effect of different drilling dimensions (undersized, regular, and oversized) in the insertion and removal torques of dental implants in a beagle dog model.

Methods: Six beagle dogs were acquired and subjected to bilateral surgeries in the radii 1 and 3 weeks before euthanasia. During surgery, 3 implants, 4 mm in diameter by 10 mm in length, were placed in bone sites drilled to 3.