The Effect of Primary Root Canal Treatment on Dentinal Tubule Penetration of Calcium Silicate-based Sealers during Endodontic Retreatment.

Introduction: The aim of this study was to evaluate the effect of previous root canal treatment on dentinal tubule penetration of calcium silicate-based sealers during endodontic retreatment and to compare 2 different (commonly used and modified) tubule penetration depth measurement techniques.

Methods: The crowns of mandibular premolar teeth were removed, and root canals were prepared (ProTaper Universal; Dentsply Sirona, York, PA) and obturated using AH Plus (AH; Dentsply DeTrey, Konstanz, Germany), MTA Fillapex (MTAF; Angelus, Londrina, Brazil), and WellRoot ST (WRST; Vericom, Gyeonggi-do, South Korea); 0.1% red Rhod-2 dye (Chemodex, St Gallen, Switzerland) was added to the sealers.

Dentinal Tubule Penetration and Dislocation Resistance of a New Bioactive Root Canal Sealer Following Root Canal Medicament Removal Using Sonic Agitation or Laser-Activated Irrigation.

Objective: To investigate the influence of sonic agitation or laser-activated irrigation techniques on the removal chlorhexidine (CHX) and modified triple antibiotic paste (mTAP) on the sealer penetration depth and dislocation resistance of Guttaflow Bioseal.

Methods: Single-rooted mandibular premolars (n=96) were prepared with rotary nickel titanium instruments and randomly divided into two groups (n=48) based on the intracanal medicaments used: Group 1, mTAP; Group 2, CHX gel. After 7 days, the specimens in each group were divided into three subgroups (n=16) based on the supplementary irrigation technique used to remove the medicaments: laser activated irrigation (Er, Cr: YSGG laser, Waterlase MD, Biolase Technology Inc.

Warm Gutta-Percha Techniques Regulate Cell Viability, Heat Shock, and Mineralized Tissue-associated Proteins of Cementoblasts.

Introduction: The aim of this study was to determine the effect of the continuous wave of condensation technique (CWCT) and the thermoplastic gutta-percha injection (TGI) technique on the messenger RNA (mRNA) expressions of heat shock proteins (HSPs) and mineralized tissue-associated proteins of the immortalized mouse cementoblasts (OCCM.30).

Methods: Crowns of human premolar teeth with single and straight canals were removed.

Adhesion of Two New Glass Fiber Post Systems Cemented with Self-Adhesive Resin Cements.

The aim of this in vitro study was to evaluate the adhesion strength of two new fiber post systems (FiberSite™ Post and Cytec™ Blanco Post) cemented with two different adhesive resin cements (Panavia™ SA and Maxcem™ Elite). Root canals of sixty extracted human mandibular premolars were prepared using ProTaper Universal™ rotary files (Dentsply Sirona Endodontics, York, PA, USA). The root canals were irrigated with 5.

Critical evaluation of fracture strength testing for endodontically treated teeth: a finite element analysis study.

Objectives: The aim of this study was to investigate whether the diameter and direction of the plunger and simulation of the periodontal ligament (PDL) affected the stress distribution in endodontically treated premolars.

Methods: A fracture strength test was simulated via finite element analysis. A base model was set up, and the following parameters were modified: plunger diameter (3 mm vs.

Effect of Different Treatment Options on Biomechanics of Immature Teeth: A Finite Element Stress Analysis Study.

Introduction: Immature teeth (IT) can be managed by using several treatment options, depending on the vitality of the tooth. The aim of this finite element stress analysis study was to evaluate the effect of different treatment procedures on the stresses in three-dimensional IT models.

Methods: Three-dimensional finite element stress analysis premolar tooth model was created as control (model 1), modified to simulate IT.

Evaluation of Related Factors in the Failure of Endodontically Treated Teeth: A Cross-sectional Study.

Introduction: The aim of this study was to review the factors related to the failure and extraction of unsuccessful endodontically treated teeth.

Methods: A total of 1000 teeth treated with nonsurgical root canal therapy were analyzed, and the following information was recorded for each patient: reasons for failure and extraction, type of tooth, presence and type of coronal restoration, smoking status, age, gender, and level of education. One main reason was recorded for each failed tooth.

Can Degradation of Adhesive Interfaces Due to Water Storage Affect Stress Distributions? A Finite-Element Stress Analysis Study.

Purpose: The aim of this finite-element stress analysis (FEA) was to determine the effect of degradation due to water storage on stress distributions in root-filled premolar models restored with composite using either a self-etch (SE) or an etch-and-rinse (E&R) adhesive.

Materials And Methods: Four premolar FEA models including root filling, MOD cavity, and composite restorations were created. The cavities were assumed to be treated by SE or E&R adhesives and stored in water for 18 months.

Evaluation of the Effect of Rotary Systems on Stresses in a New Testing Model Using a 3-Dimensional Printed Simulated Resin Root with an Oval-shaped Canal: A Finite Element Analysis Study.

Introduction: This finite element analysis study was aimed at evaluating the effects of rotary systems on stresses in photopolymerized resin root models with oval-shaped canals.

Methods: Among the data collected by computed tomographic imaging, a mandibular second premolar tooth with an oval-shaped canal was selected, recorded as Digital Imaging and Communications in Medicine, and transferred to Materialise's Interactive Medical Image Control System software. Three-dimensional modeling was performed to produce photopolymerized resin root models.

Effect of Root Filling on Stress Distribution in Premolars with Endodontic-Periodontal Lesion: A Finite Elemental Analysis Study.

Introduction: Endodontic-periodontal (EP) lesions require both endodontic and periodontal therapies. Impermeable sealing of the root canal system after cleaning and shaping is essential for a successful endodontic treatment. However, complete healing of the hard and soft tissue lesions takes time, and diseased bone, periodontal ligament, and tooth fibrous joints are reported to have an increased failure risk for a given load.

Comparison of different irrigation activation regimens and conventional irrigation techniques for the removal of modified triple antibiotic paste from root canals.

Introduction: The aim of this study was to compare the efficacy of irrigation activation regimens and conventional syringe irrigation technique in the removal of modified triple antibiotic paste (mTAP) from root canal walls.

Methods: Fifty-six extracted human mandibular premolars were prepared using ProTaper rotary files (Dentsply Maillefer, Ballaigues, Switzerland) up to size F4. The root canals were filled with mTAP medicament, and after 21 days, the roots were randomly assigned to 5 groups (n = 10) according to the irrigation regimens used: conventional syringe irrigation (CI), Self-Adjusting File (SAF; ReDent-Nova, Ra'anana, Israel), EndoVac (Discus Dental, Culver City, CA), EndoActivator (Dentsply, Tulsa, OK), and passive ultrasonic irrigation (PUI).

Effect of restoration technique on stress distribution in roots with flared canals: an FEA study.

Purpose: The aim of this finite element analysis (FEA) study was to test the effect of different restorative techniques on stress distribution in roots with flared canals.

Materials And Methods: Five three-dimensional (3D) FEA models that simulated a maxillary incisor with excessive structure loss and flared root canals were created and restored with the following techniques/materials: 1) a prefabricated post: 2) one main and two accessory posts; 3) i-TFC post-core (Sun Medical); 4) the thickness of the root was increased by using composite resin and the root was then restored using a prefabricated post; 5) an anatomic post was created by using composite resin and a prefabricated glass-fiber post. Composite cores and ceramic crowns were created.

Influence of powdered dentin on the shear bond strength of dentin bonding systems.

This study evaluated the effect of different amounts of dentin powder (DP) mixed in Clearfil SE Bond (CSB) or Single Bond (SB) on adhesion to dentin. Human third molars (n=96) were sectioned to expose the mid-coronal dentin and divided into eight experimental groups (n=12 per group), namely, Group 1: CSB, Group 2: CSB+1.5 mg DP, Group 3: CSB+3 mg DP, Group 4: CSB+4.

The use of endodontically treated and/or fiber post-retained teeth as abutments for fixed partial dentures.

The purpose of this in vitro study was to evaluate the effect of endodontic treatment with or without fiber-post restorations on the fracture strength of abutment teeth under fixed partial dentures (FPDs). Seventy extracted premolar and canine teeth were used. Groups of fiber-post-retained and root-filled teeth were endodontically treated.

An alternative adhesive strategy to optimize bonding to root dentin.

Introduction: This study examined the hypothesis that the shear-bond strengths of AH Plus (AH) and Hybrid Root Seal (HRS) to root dentin might be optimized by using a powdered dentin-reinforced bonding procedure.

Methods: The surfaces of root halves obtained from extracted human premolars were ground (800-grit silicon carbide paper), treated (5.25% NaOCl 17% EDTA for 5 minutes followed by distilled water) and randomly allocated into two groups according to the sealer and then into three subgroups according to bonding procedure.

The effect of cavity shape and hybrid layer on the stress distribution of cervical composite restorations.

Objectives: The aim of this finite elemental stress analysis study was to evaluate the effect of cavity shape and hybrid layer on the stress distribution of the mandibular premolar tooth under occlusal loading.

Methods: The mandibular premolar tooth was selected as the model based on the anatomical measurements suggested by Wheeler. Four different mathematical models were evaluated: 1) a saucer-shaped non-carious cervical lesion restored with a composite without a hybrid layer, 2) a saucer-shaped non-carious cervical lesion restored with a composite with a hybrid layer, 3) a wedge-shaped non-carious cervical lesion restored with a composite without a hybrid layer, and 4) a wedge-shaped non-carious cervical lesion restored with a composite with a hybrid layer.

Composite bond strength to intact enamel with current simplified adhesives.

Purpose: This study compared microtensile bond strength (μTBS) of six simplified adhesive systems and an etch-andrinse, one-bottle adhesive system to intact enamel.

Materials And Methods: Twenty-eight sound incisor teeth were cut at the cementoenamel junction (CEJ) under water cooling. The enamel surfaces were cleaned with pumice, randomly assigned to seven groups and treated with one of the following adhesives: Hybrid Bond (Sun Medical); AdheSE One (Ivoclar/Vivadent); One Coat 7.

Sealing ability of Hybrid Root SEAL (MetaSEAL) in conjunction with different obturation techniques.

Objective: The objective of this study was to evaluate the apical sealing ability of Hybrid Root SEAL (MetaSEAL) in conjunction with different obturation techniques.

Methodology: Sixty-eight extracted human mandibular straight single-rooted teeth with mature apices were prepared using a step-back technique and divided into 4 experimental groups (n = 15). An additional 8 teeth were prepared for controls (3 for positive, 3 for negative control, and 2 more for calculating 100% leakage).

Effect of hybrid layer and thickness on stress distribution of cervical wedge-shaped restorations.

Objectives: The aim of this finite elemental stress analysis study was to evaluate the effect of a hybrid layer and the hybrid layer thickness on the shear stress distribution in mandibular premolar teeth under occlusal loading.

Methods: The mandibular premolar tooth was selected based on the anatomical measurements suggested by Wheeler. The analysis was performed with a computer with the SAP 2000 structural analysis program.

Evaluation of gaps or voids occurring in roots filled with three different sealers.

Objectives: The purpose of this in vitro study was to evaluate gaps or voids occurring in roots filled with three different sealers.

Methods: Thirty extracted human single-rooted teeth were decoronated, instrumented using NiTi rotary instruments, divided into three groups (n=10 per group) and obturated with one of the following: Epiphany with Resilon, MetaSEAL with gutta-percha or AH Plus with gutta-percha using the match-taper single-cone technique. After storage for one week in 100% humidity at 37 degrees C, the teeth were horizontally sectioned (n=10).

Effect of artificial aging regimens on the performance of self-etching adhesives.

This in vitro study was performed to compare the microtensile bond strengths (MTBS) of current self-etching adhesives to dentin and to evaluate the effects of artificial aging [(thermocycling (TC) and/or mechanic loading (ML)] on MTBS and on nanoleakage of self-etching adhesives. Two-step (AdheSE Bond, Clearfil Protect Bond, Clearfil SE Bond, Optibond Self-Etch) and one-step (Hybrid Bond, G-bond, Clearfil Tri-S Bond, and Adper Prompt L-Pop) self-etching adhesives were tested. Resin composite build-ups were created, and the specimens were subjected to 10(4) TC, 10(5) ML, and 10(4)/10(5) TC/ML.

Effect of storage temperature on bond strength of a self-etch adhesive system to pulp chamber dentin.

Objectives: The aim of this study was to evaluate the effect of storage temperature on bond strength of a self etching primer system to pulp chamber dentin.

Methods: SE Bond (Kuraray, JAPAN) adhesive system and Clearfil Photo Posterior (Kuraray, JAPAN) composite resin were used. Eight extracted caries-free human molar teeth were used.

Corono-apical leakage of various root filling materials using two different penetration models--a 3-month study.

The purpose of this study was to analyze the sealing ability of various filling combinations in a 90 days period using fluid transport and glucose penetration models. Premolars (n = 108) were filled with either gutta-percha (groups 1-4) or Resilon (groups 5-8) core materials combined with AH Plus (groups 1, 3, 5, 7) or Epiphany (groups 2, 4, 6, 8) sealers by using cold lateral compaction (groups 1, 2, groups 5, 6) or System B with Obtura II (groups 3, 4, groups 7, 8). The sealing ability of each sample was evaluated through glucose and fluid penetration models.