Abstract Purpose To assess the effect of tooth preparation design on fracture resistance zirconia‐reinforced lithium silicate overlays. Materials and Methods This study evaluated 50 human maxillary first molars with no caries, restorations or anatomical defects. The teeth were randomly divided into five groups (n = 10/group) based for fabrication overlay restorations: (O) occlusal reduction, (OS) reduction round shoulder preparation, (OG) a central groove, (OSG) (C) (control group). All...

ABSTRACT Purpose To assess the effects of presence adjacent tooth and material type on marginal internal adaptation endocrowns fabricated by digital impression technique. Material Methods An endodontically treated molar was used for fabrication in this vitro study. Five groups specimens ( n = 17) were evaluated based tooth: three monolithic zirconia (Zir), lithium disilicate (LDS), zirconia‐reinforced silicate (ZLS) teeth, two endocrowns, one absence an anterior (second premolar; Zir‐no...

Purpose: Analyzing different patterns of maxillary sinus septa in cone-beam computed tomography (CBCT) images and predicting membrane perforations. Materials Methods:In this cross-sectional study, CBCT 222 patients ranging from 20 to 81 years old were evaluated.One hundred fifty-two (93 females 59 males) who had axial views included study.Cross-sectional used determine classifications the risk perforation using a method modified Al-Faraje et al.Variables sex, age, dental status...

Following the advent of strong adhesive bonding, conservative tooth preparation designs without a retentive form gained increasing popularity. This study aimed to evaluate marginal adaptation zirconia-reinforced lithium silicate (ZLS) overlays with different designs.Forty sound human maxillary first molars were collected and divided into four groups (n = 10) according their design for fabrication ZLS overlays: (O) anatomical occlusal reduction, (OS) reduction rounded shoulder, (OG) central...

Objective. Considering the increasing number of adults seeking orthodontic treatment, and possible need for bracket bonding to monolithic zirconia restorations, knowledge about preferred type (metal/ceramic) most efficient surface treatment is imperative achieve acceptable shear bond strength (SBS). This study aimed assess effect different treatments types on SBS high-translucent zirconia. Materials Methods. Totally, 248 disc-shaped specimens were assigned two groups metal ceramic brackets....

Abstract Objectives To compare the marginal and internal fit fracture resistance of three‐unit provisional fixed dental prostheses (FDPs) fabricated by additive, subtractive, conventional methods. Material Methods Eighty 3‐unit FDPs were on metal dies maxillary right second premolar molar four different techniques ( n = 20): The direct method using autopolymerizing polymethyl methacrylate (PMMA), indirect compression molding technique, subtractive manufacturing PMMA blocks, additive digital...

ABSTRACT Background: Detorquing value is an important factor in the amount of preload stresses during abutment screw fastening. This study evaluated percentage detorque values two‐piece machined titanium and premachined cast abutments small diameter implants. Materials Methods: Three groups five samples were evaluated. Group 1 (G1), abutments, group 2 (G2), straight that with gold‐palladium, 3 (G3), angled same alloy, before casting. Each was torque to 24 Ncm according manufacturer's...

To assess the color stability and translucency of full cubic stabilized zirconia (FSZ) following orthodontic bonding with different surface treatments coffee thermocycling (CTC).This in vitro study was conducted on 120 disc-shaped specimens FSZ. Thirty were selected as control group remained intact. The remaining randomly divided into three groups based type treatment (n = 30): airborne particle abrasion (APA), silica-coating (CoJet), carbon dioxide (CO2) laser. After metal bracket test...

To assess the fracture resistance and failure mode of endodontically treated premolars reconstructed by different preparation approaches: cervical margin relocation (CMR) crown lengthening (CL) with complete ferrule (CLF) partial (CLPF) three post core systems.

Aim:The purpose of this study was to evaluate the effect grinding, over-glazing, regrinding, and polishing on flexural strength monolithic zirconia. Materials methods:In in vitro study, 50 bar-shaped zirconia specimens were fabricated divided into 5 groups (n = 10) no-treatment control group (C), grinding (G), + glazing (GGl), (GGlG), (GGlGP).A universal testing machine used measure strength.Data analyzed using Tukey's HSD test ANOVA (p < 0.05).Results: There significant differences between...

Objective . This study aimed to assess the effect of length relocated cervical margin with casting post and core (CP), prefabricated fiber composite (PFP), polyethylene fiber‐reinforced (PEFRC) on fracture resistance marginal integrity. Materials Methods In this in vitro study, 70 sound human maxillary premolars were divided into seven groups according type system ( n = 10): control (no preparation), PFP‐3, PEFRC‐3, CP‐3 3 mm relocation (CMR), PFP‐6, PEFRC‐6, CP‐6 (with 6 CMR). The samples...

Sufficient information is not available regarding the comparative accuracy of digital and conventional impression techniques at different depths for fabrication endocrown restorations. Thus, this study aimed to compare marginal (M) internal (I) adaptation endocrowns fabricated by techniques.

The apical seal provided by a root canal filling may be breached via coronal leakage. This study aimed to compare the teeth restored with custom-made cast metal posts and cores cemented different luting agents in terms of microleakage after thermocycling.This vitro was conducted on 32 extracted single-canal teeth. Root canals were prepared step-back technique filled gutta percha sealer. 7 mm removed, post space using peeso reamers #2 #3 consecutively. After fabricating acrylic resin patterns...

Calcium is an inorganic component of the saliva, which especially important in oral and dental health. This study sought to compare unstimulated salivary calcium level dentulous edentulous patients.This case-control was conducted on 72 participants, including 36 patients. The flow rate patients mean concentration were measured compared. data analyzed using nonparametric Mann-Whitney U-test.The age participants 56.3 years. number teeth 18.9 group. No significant difference noted 0.61 ± 0.3875...

Aims: To assess the effect of history conventional denture use, number implants, age, gender, and time passed since delivery (1 3 months) on satisfaction patients with mandibular implant-supported overdentures. Materials Methods: This prospective study was conducted 54 eligible edentulous (48-74 years, 30 males 24 females). After obtaining written informed consent ethical approval, filled out a questionnaire regarding their level overdenture. Data were analyzed by generalized estimating...

ABSTRACT Background: Few studies assessed the effect of coping material (particularly milled metal copings) on retentive strength cements and reported contradictory results. Thus, this study aims to assess marginal leakage implant-supported zirconia cobalt-chromium (Co-Cr) copings cemented with different temporary cements. Materials Methods: In in vitro study, Zirconia Co-Cr were fabricated 100 straight titanium abutments. Each group was divided into five subgroups ( n = 10) for use cements:...

A Survey of the Relationship between Academic Burnout and Achievement Dental Students Guilan University Medical Sciences

Hamid Neshandar Asli, DDS, PhD/Zahra Dalili Kajan, PhD/Negar Khosravifard, PhD/Seyedeh Newsha Roudbary, DDS/Elahe Rafiei, MS: Purpose: To assess the success rates of cone beam computed tomography (CBCT) in identifying locations and directions abutment screw access holes (ASAHs) metal-ceramic all-ceramic implant restorations. Materials Methods: Thirty-two implants were inserted into four clear acrylic casts. Metal-ceramic crowns placed on two successive tasks. A maxillofacial radiologist...