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Research paper thumbnail of Comparative Evaluation of Fracture Resistance between Two Alumina Ceramic Copings

In spite of ceramics' desirable esthetics and compressive strength, they are inherently prone to ... more In spite of ceramics' desirable esthetics and compressive strength, they are inherently prone to fracture and are weak against tensile and torsional loads. In-Ceram Alumina is a type of reinforced alumina which has been used as a core material for crowns and three units anterior bidges since 90s. Turkom-Cera is presented in the market recently which uses a simple method to produce single and multiple unit anterior and posterior restorations. The purpose of this study is to evaluate the fracture resistance of copings made by these systems. Materials & Methods: 40 brass dyes were prepared and divided into two groups. To make the copings, impression was taken and model dyes were made. 20 ceramic coping were prepared according to manufacturers instructions for each group, cemented to brass dyes and kept in 100% moisture for one week. Load to fracture test was performed by Universal testing machine and load was applied by a speed of 0.5 mm/min. Fracture load was recorded for each specimen. Data were collected and entered to the SPSS software and t-test was done. Results: The average fracture load for Turkom-Cera was 1273 N and was 1079 N for In-Ceram Alumina. The maximum and minimum values for the first group was 2490, 530 N and for the second group was 1490, 714 N respectively. According to t-test results with P-value<0.05 there was no significant difference between the two groups. Conclusion: According to the close results for both groups, clinical performance of the Turkom-Cera ceramic copings would be similar to In-Ceram Alumina and a wide range of clinical use could be anticioated for this system.

Research paper thumbnail of The Effect of two Shading Techniques on Value of Zirconia-Based Crowns

Journal of Dentistry Shiraz University of Medical Sciences, Jun 1, 2014

Research paper thumbnail of Evaluation of the Effect of Axial Wall Modification and Coping Design on the Retention of Cement-retained Implant-supported Crowns

Journal of Dental Research, Dental Clinics, Dental Prospects, 2015

Background. This study evaluated the antimicrobial activity of Tetraacetylethylenediamine-sodium ... more Background. This study evaluated the antimicrobial activity of Tetraacetylethylenediamine-sodium perborate (TAED-SP) in comparison to 2.5% and 5% sodium hypochlorite (NaOCl) against Enterococcus faecalis. Methods. A standard suspension of E. faecalis was inoculated on 60 plates containing Mueller-Hinton agar culture medium. Four sterile disks of Beckman filtration paper were placed on each plate. TAED-SP, 5% and 2.5% NaOCl were placed on three disks. Sterile physiologic saline was placed on the fourth disk as negative control. After 24-hour incubation, the diameter of the inhibition zone around the disks was measured using a transparent ruler. One-way Analysis of Variance (ANOVA) was used to compare the mean zone of microbial growth in the groups. P-values less than 0.05 were considered statistically significant. Results. There was a significant difference in the diameter of the inhibition zones between groups (P < 0.05). The Tukey post hoc test showed a higher diameter of the inhibitory zone with TAED-SP than that of 2.5% NaOCl. However, there were no significant differences between the inhibitory zones of TAED-SP and 5% NaOCl. Conclusion. TAED-SP and 5% NaOCl have similar antibacterial activity against E. faecalis; however, TAED-SP has a greater antibacterial effect compared to 2.5% NaOCl.

Research paper thumbnail of Effect of abutment modification and cement type on retention of cement-retained implant supported crowns

Journal of dentistry (Tehran, Iran), 2014

Provisional cements are commonly used to facilitate retrievability of cement-retained fixed impla... more Provisional cements are commonly used to facilitate retrievability of cement-retained fixed implant restorations; but compromised abutment preparation may affect the retention of implant-retained crowns.The purpose of this study was to investigate the effect of abutment design and type of luting agent on the retentive strength of cement-retained implant restorations. Two prefabricated abutments were attached to their corresponding analogs and embedded in an acrylic resin block. The first abutment (control group) was left intact without any modifications. The screw access channel for the first abutment was completely filled with composite resin. In the second abutment, (test group) the axial wall was partially removed to form an abutment with 3 walls. Wax models were made by CAD/CAM. Ten cast copings were fabricated for each abutment. The prepared copings were cemented on the abutments by Temp Bond luting agent under standardized conditions (n=20). The assemblies were stored in 100% ...

Research paper thumbnail of Marginal and internal fit of CAD/CAM and slip-cast made zirconia copings

Journal of dental research, dental clinics, dental prospects, 2012

CAD/CAM systems facilitate the use of zirconia substructure materials for all-ceramic copings. Th... more CAD/CAM systems facilitate the use of zirconia substructure materials for all-ceramic copings. This in vitro study investigated the marginal and internal fit of zirconia copings made with CAD/CAM system and slip-casting method. Sixteen CAD/CAM made zirconia copings and 16 slip-cast made zirconia copings were fabri-cated and cemented with glass-ionomer cement to their respective master abutment models, and thickness of the cement layer was measured at specific measuring points with stereomicroscope. In the left wall, the mean axial internal gap was greater in group one than group two (62.49 vs. 48.14) (P =0.007), in the right wall the mean axial internal gap was greater in group one than group two (44.87 vs. 40.91) (P = 0.465). The oc-clusal internal gap was greater in group one than group two (118.81 vs. 102.11) (P =0.423). The mean marginal gap also was greater in group one than group two (46.67 vs. 44.29) (P = 0.863). The differences in marginal fit between these two methods were ...

Research paper thumbnail of A Clinical Comparative Study of Cadiax Compact II and Intraoral Records Using Wax and Addition Silicone

The International Journal of Prosthodontics, 2014

This assignment applies to all translations of the Work as well as to preliminary display/posting... more This assignment applies to all translations of the Work as well as to preliminary display/posting of the abstract of the accepted article in electronic form before publication. If any changes in authorship (order, deletions, or additions) occur after the manuscript is submitted, agreement by all authors for such changes must be on file with the Publisher. An author's name may be removed only at his/her written request. (Note: Material prepared by employees of the US government in the course of their official duties cannot be copyrighted.

Research paper thumbnail of Prosthodontic Rehabilitation of a Shotgun Injury: A Patient Report

Journal of Prosthodontics, 2010

This report describes the prosthodontic rehabilitation of a shotgun patient traumatized in the ma... more This report describes the prosthodontic rehabilitation of a shotgun patient traumatized in the maxillary, mandibular, and nasal areas resulting in severe problems in her esthetics, phonetics, and mastication. The patient was treated with removable partial prostheses using tooth, soft tissue, and implant support.

Research paper thumbnail of Evaluation of the Cadiax Compact� II Accuracy in Recording Preadjusted Condylar Inclinations on Fully Adjustable Articulator

The Journal of Contemporary Dental Practice, 2012

Background: Mandibular movement analysis is a critical step in making the functional occlusal mor... more Background: Mandibular movement analysis is a critical step in making the functional occlusal morphology and improving the diagnosis and treatment of temporomandibular joint disorders (TMDs). Cadiax Compact ® is an electronic condylograph that claims to record the horizontal condylar inclination (HCI), Bennett angle (BA), and relative shape of the articular eminence. This study aims at assessing the accuracy of Cadiax compact ® II in its claimed abilities. Materials and methods: The electronic condylograph (Cadiax Compact ® II) was fitted on the fully adjustable articulator (gamma dental reference-SL). After setting of HCI and BA on the arbitrary degrees, eccentric movements were produced manually on the articulator. The cadiax recorded these preadjusted angles and the accuracy of its recordings was assessed by comparison of the results with the preadjusted HCI, BA and color inserts as references. Results: The majority of the comparisons showed statistically significant differences between articulator settings and cadiax recordings. However, the maximum difference was about 2.5 0 which seems acceptable for clinical practice. Conclusion: The obtained results showed that cadiax compact is an accurate and reliable instrument for diagnostic purposes, yielding reproducible measurements. Despite this, Cadiax is a technically sensitive device that can preclude its routine usage.

Research paper thumbnail of Comparative Evaluation of Fracture Resistance between Two Alumina Ceramic Copings

In spite of ceramics' desirable esthetics and compressive strength, they are inherently prone to ... more In spite of ceramics' desirable esthetics and compressive strength, they are inherently prone to fracture and are weak against tensile and torsional loads. In-Ceram Alumina is a type of reinforced alumina which has been used as a core material for crowns and three units anterior bidges since 90s. Turkom-Cera is presented in the market recently which uses a simple method to produce single and multiple unit anterior and posterior restorations. The purpose of this study is to evaluate the fracture resistance of copings made by these systems. Materials & Methods: 40 brass dyes were prepared and divided into two groups. To make the copings, impression was taken and model dyes were made. 20 ceramic coping were prepared according to manufacturers instructions for each group, cemented to brass dyes and kept in 100% moisture for one week. Load to fracture test was performed by Universal testing machine and load was applied by a speed of 0.5 mm/min. Fracture load was recorded for each specimen. Data were collected and entered to the SPSS software and t-test was done. Results: The average fracture load for Turkom-Cera was 1273 N and was 1079 N for In-Ceram Alumina. The maximum and minimum values for the first group was 2490, 530 N and for the second group was 1490, 714 N respectively. According to t-test results with P-value<0.05 there was no significant difference between the two groups. Conclusion: According to the close results for both groups, clinical performance of the Turkom-Cera ceramic copings would be similar to In-Ceram Alumina and a wide range of clinical use could be anticioated for this system.

Research paper thumbnail of The Effect of two Shading Techniques on Value of Zirconia-Based Crowns

Journal of Dentistry Shiraz University of Medical Sciences, Jun 1, 2014

Research paper thumbnail of Evaluation of the Effect of Axial Wall Modification and Coping Design on the Retention of Cement-retained Implant-supported Crowns

Journal of Dental Research, Dental Clinics, Dental Prospects, 2015

Background. This study evaluated the antimicrobial activity of Tetraacetylethylenediamine-sodium ... more Background. This study evaluated the antimicrobial activity of Tetraacetylethylenediamine-sodium perborate (TAED-SP) in comparison to 2.5% and 5% sodium hypochlorite (NaOCl) against Enterococcus faecalis. Methods. A standard suspension of E. faecalis was inoculated on 60 plates containing Mueller-Hinton agar culture medium. Four sterile disks of Beckman filtration paper were placed on each plate. TAED-SP, 5% and 2.5% NaOCl were placed on three disks. Sterile physiologic saline was placed on the fourth disk as negative control. After 24-hour incubation, the diameter of the inhibition zone around the disks was measured using a transparent ruler. One-way Analysis of Variance (ANOVA) was used to compare the mean zone of microbial growth in the groups. P-values less than 0.05 were considered statistically significant. Results. There was a significant difference in the diameter of the inhibition zones between groups (P < 0.05). The Tukey post hoc test showed a higher diameter of the inhibitory zone with TAED-SP than that of 2.5% NaOCl. However, there were no significant differences between the inhibitory zones of TAED-SP and 5% NaOCl. Conclusion. TAED-SP and 5% NaOCl have similar antibacterial activity against E. faecalis; however, TAED-SP has a greater antibacterial effect compared to 2.5% NaOCl.

Research paper thumbnail of Effect of abutment modification and cement type on retention of cement-retained implant supported crowns

Journal of dentistry (Tehran, Iran), 2014

Provisional cements are commonly used to facilitate retrievability of cement-retained fixed impla... more Provisional cements are commonly used to facilitate retrievability of cement-retained fixed implant restorations; but compromised abutment preparation may affect the retention of implant-retained crowns.The purpose of this study was to investigate the effect of abutment design and type of luting agent on the retentive strength of cement-retained implant restorations. Two prefabricated abutments were attached to their corresponding analogs and embedded in an acrylic resin block. The first abutment (control group) was left intact without any modifications. The screw access channel for the first abutment was completely filled with composite resin. In the second abutment, (test group) the axial wall was partially removed to form an abutment with 3 walls. Wax models were made by CAD/CAM. Ten cast copings were fabricated for each abutment. The prepared copings were cemented on the abutments by Temp Bond luting agent under standardized conditions (n=20). The assemblies were stored in 100% ...

Research paper thumbnail of Marginal and internal fit of CAD/CAM and slip-cast made zirconia copings

Journal of dental research, dental clinics, dental prospects, 2012

CAD/CAM systems facilitate the use of zirconia substructure materials for all-ceramic copings. Th... more CAD/CAM systems facilitate the use of zirconia substructure materials for all-ceramic copings. This in vitro study investigated the marginal and internal fit of zirconia copings made with CAD/CAM system and slip-casting method. Sixteen CAD/CAM made zirconia copings and 16 slip-cast made zirconia copings were fabri-cated and cemented with glass-ionomer cement to their respective master abutment models, and thickness of the cement layer was measured at specific measuring points with stereomicroscope. In the left wall, the mean axial internal gap was greater in group one than group two (62.49 vs. 48.14) (P =0.007), in the right wall the mean axial internal gap was greater in group one than group two (44.87 vs. 40.91) (P = 0.465). The oc-clusal internal gap was greater in group one than group two (118.81 vs. 102.11) (P =0.423). The mean marginal gap also was greater in group one than group two (46.67 vs. 44.29) (P = 0.863). The differences in marginal fit between these two methods were ...

Research paper thumbnail of A Clinical Comparative Study of Cadiax Compact II and Intraoral Records Using Wax and Addition Silicone

The International Journal of Prosthodontics, 2014

This assignment applies to all translations of the Work as well as to preliminary display/posting... more This assignment applies to all translations of the Work as well as to preliminary display/posting of the abstract of the accepted article in electronic form before publication. If any changes in authorship (order, deletions, or additions) occur after the manuscript is submitted, agreement by all authors for such changes must be on file with the Publisher. An author's name may be removed only at his/her written request. (Note: Material prepared by employees of the US government in the course of their official duties cannot be copyrighted.

Research paper thumbnail of Prosthodontic Rehabilitation of a Shotgun Injury: A Patient Report

Journal of Prosthodontics, 2010

This report describes the prosthodontic rehabilitation of a shotgun patient traumatized in the ma... more This report describes the prosthodontic rehabilitation of a shotgun patient traumatized in the maxillary, mandibular, and nasal areas resulting in severe problems in her esthetics, phonetics, and mastication. The patient was treated with removable partial prostheses using tooth, soft tissue, and implant support.

Research paper thumbnail of Evaluation of the Cadiax Compact� II Accuracy in Recording Preadjusted Condylar Inclinations on Fully Adjustable Articulator

The Journal of Contemporary Dental Practice, 2012

Background: Mandibular movement analysis is a critical step in making the functional occlusal mor... more Background: Mandibular movement analysis is a critical step in making the functional occlusal morphology and improving the diagnosis and treatment of temporomandibular joint disorders (TMDs). Cadiax Compact ® is an electronic condylograph that claims to record the horizontal condylar inclination (HCI), Bennett angle (BA), and relative shape of the articular eminence. This study aims at assessing the accuracy of Cadiax compact ® II in its claimed abilities. Materials and methods: The electronic condylograph (Cadiax Compact ® II) was fitted on the fully adjustable articulator (gamma dental reference-SL). After setting of HCI and BA on the arbitrary degrees, eccentric movements were produced manually on the articulator. The cadiax recorded these preadjusted angles and the accuracy of its recordings was assessed by comparison of the results with the preadjusted HCI, BA and color inserts as references. Results: The majority of the comparisons showed statistically significant differences between articulator settings and cadiax recordings. However, the maximum difference was about 2.5 0 which seems acceptable for clinical practice. Conclusion: The obtained results showed that cadiax compact is an accurate and reliable instrument for diagnostic purposes, yielding reproducible measurements. Despite this, Cadiax is a technically sensitive device that can preclude its routine usage.