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Papers by farzaneh farid

This clinical report describes a treatment option for replacement of a missing mandib-ular anteri... more This clinical report describes a treatment option for replacement of a missing mandib-ular anterior tooth using InCeram resin bonded fixed partial denture (RBFPD). The conventional approach for replacing mandibular incisors dictates the placement of ei-ther a conventional porcelain-fused-to-metal (PFM) bridge, Maryland bridge, or fiber-reinforced composite veneer bridge and several appearance-related disadvantages have been reported in the use of a prosthesis that incorporates a metal substructure. The InCeram bridge is a minimally invasive restoration and eliminates undesirable incisal graying frequently observed in metal RBFPDs. This method was successfully clinically applied to overcome shortcomings of other approaches that may require a minimal invasive technique to preserve lasting sound tooth structure.

Journal of Dentistry, 2012

To evaluate the influence of core thickness and fabrication stages on the marginal accuracy of IP... more To evaluate the influence of core thickness and fabrication stages on the marginal accuracy of IPS e.max Press crowns. Twenty IPS e.max Press crowns, 1.5mm thick, were fabricated on metal dies. The crowns had two different core thicknesses, 0.8mm for group A and 1mm for group B, ten for each group. Marginal gap was measured after each stage of core fabrication, veneering and glaze firing. The specimens were not cemented and the measurements were made at four points on metal dies using a stereomicroscope (×120). Data were analyzed by SPSS software and independent t-test. Mean marginal gaps measured after each stage for group A were 13.5 (±1.4) μm, 33.9 (±2.3) μm and 40.5(±1.7) μm, and for group B these figures were 14.9(±2.0) μm, 35.5(±2.2) μm and 41.3(±2.0) μm. There were no statistically significant differences in marginal gap values between the two groups (p&amp;gt;0.1). Significant increase in gap was observed after the veneering stage in both groups (p&amp;lt;0.05). After glazing, no significant increase in gap was detected. IPS e.max Press crowns have an acceptable marginal fit. Increasing thickness of core does not increase marginal fitness.

Background and Aims: Increase of esthetic demands among dental patients has led to development an... more Background and Aims: Increase of esthetic demands among dental patients has led to development and wide spread use of tooth colored ceramic systems for fabricating fixed restorations. However, they do not have same capability of matching the target color. The aim of this study was to compare the color coordinates of three widely used systems with A2 tab from a Vita Lumin Classic shade guide. Materials and Methods: In this study, three ceramic systems were tested. The metal-ceramic(MCR) with 0.5 mm core and 1 mm Ceramco lll veneering layer; the all ceramic (CE) with 0.5 mm Cercon core and 1 mm Cercon Ceram veneering layer, and the all porcelain (VM7) with 1.5 mm Vita VM7. For each system, 15 disks (1.5mm×10mm) were made in Vita A2 shade. L*a*b* coordinates of the samples were measured by spectrophotometer and the color difference with Vita A2 shade was calculated. The data were analyzed using one way ANOVA and multiple Tukey tests. Results: The color coordinates of the target shade w...

Journal of Dental Medicine, 2012

Background and Aims: The purpose of this study was to design a new device assisting dental studen... more Background and Aims: The purpose of this study was to design a new device assisting dental students to measure the tapering of the prepared teeth for fixed crown prosthesis in which the desired tapering for better clinical prognosis could be obtained. Materials and Methods: The designed device in this study had two arms that were placed on two opposite walls of the prepared teeth. To evaluate the validity and reliability of this device, 3 dies with different degrees (13, 29 and 45°) were used and 20 teeth were prepared by dental students with undefined tapering degrees. The measurements of tapering were performed by six last year-dental students in two different time periods. Comparison of errors in measurements on standard dies between observers and between time intervals were analyzed by (Wilcoxon) Paired t-test with a significance level of α=0.05. Results: For the three dies used in this study, we compared the differences for each measurement taken by observers with the standard ...

Journal of Dentistry (Tehran, Iran), 2018

Objectives: The aim was to investigate the effect of intracanal irrigants and agents on the bond ... more Objectives: The aim was to investigate the effect of intracanal irrigants and agents on the bond strength of intraradicular fiber posts to dentin. Materials and Methods: Root canals of 72 decoronated single-rooted premolars were cleaned, shaped, and obturated with gutta-percha and AH26. The specimens were incubated at 37°C and 100% humidity for seven days. Next, the coronal 10 mm of the canals were prepared to receive size 2 D.T. Light fiber post, and the specimens were randomly allocated into six groups according to the irrigants used after post space preparation: normal saline (control group), 5.25% sodium hypochlorite (NaOCl)/15 seconds, 17% ethylenediaminetetraacetic acid (EDTA)/60 seconds, 2% chlorhexidine (CHX)/5 minutes, MTAD/5 minutes, and acid-etching/15 seconds. All canals were rinsed with normal saline and dried. Fiber posts were cemented using Panavia F2.0. After 24 hours, two mid-root slices of 1mm thickness were obtained from each specimen. Push-out bond strength test ...

Introduction: Dentinal canal walls are in direct contact with endodontic sealers prior to post sp... more Introduction: Dentinal canal walls are in direct contact with endodontic sealers prior to post space preparation and luting cements after post space preparation. This direct contact may affect the bond strength of intraradicular posts to root dentin. This study aimed to assess the effect of three different sealers on the bond strength of fiber posts to root dentin. Methods and Materials: The canals of 56 extracted single-rooted human premolars after selection and decoronation were prepared. For obturation of the canals, specimens were randomly divided into four groups (n=14) according to the type of sealer used in conjunction with gutta-percha: group 1 (control) without any sealer; group 2 with AH-Plus sealer (resin based); group 3 with Dorifill sealer (ZOE-based); and group 4 with BC Sealer (calcium silicate-based). Nine mm-deep post space was prepared in the canal of each specimen. Intraradicular fiber posts were cemented using dual-cure resin cement (Panavia F2.0). Sections of 1 ...

Rapid prototyping is a set of technicality which applied to create a scale model of a physical pa... more Rapid prototyping is a set of technicality which applied to create a scale model of a physical part or assembly rapidly utilizing three-dimensional computer aided design (CAD) data. 3D printing or "additive layer manufacturing" technology was used to Develop the part or assembly. It is a CAD/CAM technology which was created initially to manufacture prototypes for industrial purposes. RP technology encouraged the configuration and quick generation of mass quantities of precise parts by the industrial manufacturing in a convenient time with exactness and pace. In the previous two decades this technology was utilized efficiently in the medical field with a promising results. In this review the technique, methods and various uses of this fast emerging technology regarding prosthodontic will be discussed.

Journal of Dental Medicine, 2017

ديرف هنازرف رتكد ١  يدامتعا ماردپ رتكد ٢ يعيفش داهرف رتكد ٣ ١ هورگ رايداتسا يشزومآ ينادند ياهزتو... more ديرف هنازرف رتكد ١  يدامتعا ماردپ رتكد ٢ يعيفش داهرف رتكد ٣ ١ هورگ رايداتسا يشزومآ ينادند ياهزتورپ ، يكشزپنادند هدكشناد ، يكشزپ مولع هاگشناد ينامرد ،يتشادهب تامدخ و نارهت رهت ، ناريا ،نا ؛ ع تاقيقحت زكرم وض ناريا ،نارهت ،نارهت ينامرد يتشادهب تامدخ و يكشزپ مولع هاگشناد ،يكشزپنادند مولع هدكشهوژپ ،يكشزپنادند ٢ كشزپنادند ، يكشزپنادند هدكشناد ، يكشزپ مولع هاگشناد ينامرد ،يتشادهب تامدخ و نارهت ناريا ،نارهت ، ٣ هورگ رايداتسا يشزومآ تسيز ينادند داوم ، يكشزپنادند هدكشناد ، يكشزپ مولع هاگشناد د ،يتشادهب تامدخ و ينامر نارهت رهت ، ناريا ،نا

Journal of Dentistry (Tehran, Iran), 2016

During dental education, dental students learn how to examine patients, make diagnosis, plan trea... more During dental education, dental students learn how to examine patients, make diagnosis, plan treatment and perform dental procedures perfectly and efficiently. However, progresses in computer-based technologies including virtual reality (VR) simulators, augmented reality (AR) and computer aided design/computer aided manufacturing (CAD/CAM) systems have resulted in new modalities for instruction and practice of dentistry. Virtual reality dental simulators enable repeated, objective and assessable practice in various controlled situations. Superimposition of three-dimensional (3D) virtual images on actual images in AR allows surgeons to simultaneously visualize the surgical site and superimpose informative 3D images of invisible regions on the surgical site to serve as a guide. The use of CAD/CAM systems for designing and manufacturing of dental appliances and prostheses has been well established. This article reviews computer-based technologies, their application in dentistry and the...

Journal of Craniomaxillofacial Research, 2019

Statement of Problem: Prosthetic treatments account for more than half of the all provided dental... more Statement of Problem: Prosthetic treatments account for more than half of the all provided dental services, as well as the highest number of lawsuits in some countries. The quality of Prosthodontics postgraduate programs has profound effect on the improvement of provided patient health care and reduction of patient complaints. Goal: The goal of this study was to survey different universities around the globe for the duration and subjects of Prosthodontics specialty programs, the title of degree awarded and the programs that are offered in conjunction with other disciplines. Methods and Materials: This study surveyed Prosthodontics specialty programs offered by different universities available on their websites, and reviewed published research on this subject using search engines such as Google, Pubmed and Medline. The published Accreditation Standards for the program and minimum requirements for achieving competency after completion of the program was reviewed. Result: The results o...

Indian Journal of Public Health Research & Development, 2019

Surface roughness influences the marginal and internal adaptation of the prosthesis. It also can ... more Surface roughness influences the marginal and internal adaptation of the prosthesis. It also can affect the accuracy of scanned data in CAD/CAM techniques.

Journal of Dental Research, Dental Clinics, Dental Prospects, 2018

Background. This study investigated the effect of the thickness of two resin cements on push-out ... more Background. This study investigated the effect of the thickness of two resin cements on push-out bond strength of fiber posts to root dentin. Methods. Sixty decoronated single-rooted teeth were endodontically treated. The specimens were then randomly allocated to two groups (n=30); group 1: drill size 90 w, matching the size of fiber posts used; group 2: drill size 110, larger than the posts. The specimens in each group were divided into 2 subgroups (n=15); subgroup SE, in which the posts were cemented with self-etch Panavia F2.0 and subgroup SA, in which self-adhesive Panavia cement was used. After 72 hours, 2 slices with 1 mm of thickness were prepared from the mid-root of each specimen. Push-out bond strength test was performed in a universal testing machine at a crosshead speed of 1 mm/min. Data were analyzed with two-way ANOVA and t-test. Results. The mean bond strengths of the posts cemented in matched-size spaces for SE and SA groups were 4.02±1.6 and 4.12±2.3 MPa, respective...

Journal of dentistry (Tehran, Iran), 2014

This clinical report describes a treatment option for replacement of a missing mandibular anterio... more This clinical report describes a treatment option for replacement of a missing mandibular anterior tooth using InCeram resin bonded fixed partial denture (RBFPD). The conventional approach for replacing mandibular incisors dictates the placement of either a conventional porcelain-fused-to-metal (PFM) bridge, Maryland bridge, or fiber-reinforced composite veneer bridge and several appearance-related disadvantages have been reported in the use of a prosthesis that incorporates a metal substructure. The InCeram bridge is a minimally invasive restoration and eliminates undesirable incisal graying frequently observed in metal RBFPDs. This method was successfully clinically applied to overcome shortcomings of other approaches that may require a minimal invasive technique to preserve lasting sound tooth structure.

Journal of Prosthodontic Research, 2013

The aim of this study was to compare the effects of two endodontic sealers on the retention of po... more The aim of this study was to compare the effects of two endodontic sealers on the retention of posts cemented with zinc phosphate or resin cement. Materials and methods: Crowns of 72 mandibular premolars were removed at the cementoenamel junction. Root canals were prepared and specimens were randomly divided into two groups of 36. In each group, 12 specimens were obturated with gutta percha only; 12 specimens with gutta percha/ZOE sealer and 12 specimens with gutta percha/AH26. In the first group, 10 mm Post spaces were prepared with Peeso reamers size 4 and, size 5 stainless steel Paraposts were cemented in with zinc phosphate. In the second group, 10 mm Post spaces were prepared with Fiber Lux size 5.5 drills and size 5 Paraposts were cemented with Panavia F 2.0. After mounting in resin blocks, posts were pulled out by universal testing machine at 1 mm/min and results were analyzed by two-way ANOVA and Dunnett test. Results: Mean forces (in Newtons) required to remove posts cemented with zinc phosphate in canals obturated without sealer, with ZOE, and with AH26 sealers were 270 AE 83, 281 AE 128 and 266 AE 67, respectively; and for posts cemented with Panavia F 2.0 were 520 AE 290, 464 AE 212 and 229 AE 108, respectively. Statistical analysis showed that AH26 significantly reduced retention of posts cemented with Panavia F 2.0 (p < 0.05). Conclusion: Different sealers had no significant effect on retention of posts cemented with zinc phosphate. However posts cemented with Panavia F 2.0 showed reduced retention in canals obturated with AH26.

Journal of Prosthodontics, 2012

Purpose: Differences in core and veneer coefficients of thermal expansion, firing shrinkage, and ... more Purpose: Differences in core and veneer coefficients of thermal expansion, firing shrinkage, and speed of increasing and decreasing the temperature may generate stress in veneered all-ceramic restorations. Given the necessity of performing multiple firing cycles to achieve improved contour, color, and esthetics, the purpose of this study was to determine the effect of multiple firing cycles on the microtensile bond strength (MTBS) of zirconia core to the porcelain veneer in zirconia-based all-ceramic restorations. Materials and Methods: Thirty blocks (12 × 12 × 4 mm 3) of semi-sintered zirconia were machined and sintered according to manufacturer's instruction. Specimens were placed in three groups based on the number of firing cycles (4, 6, 8) for the veneering process. After veneering, the specimens were sectioned into microbars with 8 mm length and 1 mm cross-section. Twenty sound microbars in each group were stressed to failure in a microtensile tester machine at 1 mm/min. Fractured specimens were surveyed under a scanning electron microscope and classified as cohesive in core, cohesive in veneer, and mixed. MTBS data were analyzed using one-way ANOVA and Tukey test (p < 0.05). Results: The mean MTBS (MPa) after 4, 6, and 8 firing cycles were 30.33 ± 2.13, 27.43 ± 1.79, and 25.06 ± 1.76, respectively. There was a statistically significant difference between the bond strengths of each of the three groups (p < 0.001). Conclusion: Increase in firing cycles decreased MTBS. Most of the failures (90-95%) in all three groups were cohesive in the veneering porcelain and did not change as the number of firing cycles increased.

The Open Dentistry Journal, 2021

Aim: Close adaptation of cemented CAD/CAM restorations to their abutments is highly dependent on ... more Aim: Close adaptation of cemented CAD/CAM restorations to their abutments is highly dependent on precise impressions and accurate replicas of teeth and adjacent oral tissues. This in-vitro study compared the effect of two die materials, as physical replicas of prepared teeth, on internal and marginal adaptations of zirconia copings to their corresponding abutments. Materials and Methods: A virtual model simulating a prepared premolar was designed and used for the milling of thirty identical metal models. Impression was taken of all models by Polyvinyl siloxane material. Fifteen impressions were poured in with Type IV stone and the other fifteen with polyurethane resin to make dies. All dies were scanned, and for each of them, zirconia coping was designed and milled. The copings were cemented to their corresponding metal models. Marginal gap between each coping and its metal model was measured at 20 points with a stereomicroscope (×60). Then the specimens were sectioned into two halv...

Journal of Islamic Dental Association of IRAN

Background and Aim: Marginal adaptation has a significant role in the success and longevity of in... more Background and Aim: Marginal adaptation has a significant role in the success and longevity of indirect restorations. This experimental study compared the effect of intraoral and extraoral scanning on the marginal adaptation of the crowns which was made using the CEREC AC system. Materials and Methods: A Typodont maxillary first molar was prepared and served as the master die for an all-ceramic restoration. In the first group, the model was scanned ten times directly by the intraoral scanner. In the second group, ten conventional impressions were made from Typodont, and the extraoral scanner scanned the resulting gypsum casts. The data was used to design and build crowns from IPS e.max CAD blocks. The crowns were placed on the prepared tooth, and the marginal gap was measured at 16 points by a stereomicroscope at ×35 magnification. Collected data were analyzed using t-test. Results: The mean marginal gap for intraoral and extraoral groups were 74.83 ± 10.07 μm and 102.56 ± 6.89 μm respectively. The gap was significantly less in the intraoral group (P-value = 0.001). Conclusion: Marginal adaptation was clinically acceptable in both groups, although the results of intraoral scanning showed significantly lower gap than extraoral scanning.