Neset Volkan Asar | Gazi University (original) (raw)

Papers by Neset Volkan Asar

Materials & Design (1980-2015), 2010

The aim of this study is to evaluate the effect of wollastonite (CaSiO3) material on the linear f... more The aim of this study is to evaluate the effect of wollastonite (CaSiO3) material on the linear firing shrinkage and flexural strength of dental aluminous core porcelain. Twenty five specimens were prepared in a manner that each five of them contained 0%, 2%, 3%, 4%, and 5% wollastonite by weight. The linear firing shrinkage values were determined according to the formula given in the standard ANSI/ADA (American National Standards Institute/American Dental Association) 69 and the flexural strength of the specimens was evaluated using 3-point bending test. The results of this study showed that addition of wollastonite reduced the linear firing shrinkage and increased the flexural strength of dental aluminous core porcelain. The highest reduction (approx. 20%) in the linear firing shrinkage was obtained by the addition of 5% wollastonite. Kruskal-Wallis test found a statistically significant difference among the mean linear firing shrinkage values of the porcelain groups at the 95% confidence level (p < 0.05). Mann Whitney U statistical test was performed to demonstrate which porcelain groups show statistically significant difference. In spite of achieving 30% increase in the flexural strength by the addition of 2% wollastonite, no statistically significant difference was found among the mean flexural strength values of the porcelain groups (p > 0.05).

Journal of Oral Rehabilitation, Oct 1, 2009

Resonance frequency (RF) analysis is a non-invasive, objective and sensitive technique developed ... more Resonance frequency (RF) analysis is a non-invasive, objective and sensitive technique developed for implantology where it measures the stability of the implant in osteotomy site. Although many studies were performed by the previous electronic version of RF analyzer, a very limited number of studies were carried out with the new magnetic wireless version. The aim of the study was to evaluate the relation between insertion torques, primary and secondary stability of self-tapping tapered implant systems. Thirteen subjects were treated with 42 endosseous implants using two-stage surgical procedure. The maximal insertion torque values were recorded prior to RF analysis during surgery. Six months after surgery, the secondary stability values were measured by the RF analysis. The average maximal insertion torque and primary and secondary magnetic RF values were 33 +/- 11 N cm and 66 +/- 12 ISQ and 71.9 +/- 6 ISQ for 42 implants respectively. The correlation between insertion torque and RF values were indicated to be statistically significant (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01). Significantly higher maximal insertion torque, and primary and secondary magnetic RF values were achieved in mandibular sites compared with maxillary areas (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01). No significant differences were measured for all parameters when both systems were compared with each other (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 0.05). There was a strong correlation between the insertion torque, primary and secondary magnetic RF values of self-tapping tapered endosseous implant used. Further studies are needed to understand the impact of the wireless magnetic RF analysis technique in clinics.

Journal of Prosthetic Dentistry, Nov 1, 2014

Statement of problem. Bacterial plaque must be routinely removed from teeth, adjacent structures,... more Statement of problem. Bacterial plaque must be routinely removed from teeth, adjacent structures, and prostheses. However, the removal of this plaque can inadvertently increase the risk of future bacterial adhesion. Purpose. The purpose of this investigation was to assess the change in the surface roughness of 3 different surfaces after dental prophylactic instrumentation and how this influenced bacterial adhesion. Material and methods. Forty specimens each of Type III gold alloy, lithium disilicate, and zirconia were fabricated in the same dimensions. The specimens were divided into 4 groups: ultrasonic scaler, stainless steel curette, prophylaxis cup, and control. Pretreatment surface roughness measurements were made with a profilometer. Surface treatments in each group were performed with a custom mechanical scaler. Posttreatment surface roughness values were measured. In turn, the specimens were inoculated with Streptococcus mutans, Lactobacillus acidophilus, and Actinomyces viscosus. Bacterial adhesion was assessed by rinsing the specimens with sterile saline to remove unattached cells. The specimens were then placed in sterile tubes with 1 mL of sterile saline. The solution was plated and quantified. Scanning electron microscopy was performed. The statistical analysis of surface roughness was completed by using repeated-measures single-factor ANOVA with a Bonferroni correction. Results. The surface roughness values for gold alloy specimens increased as a result of prophylaxis cup treatment (0.221 to 0.346 Ra) (P<.01) and stainless steel curette treatment (0.264 to 1.835 Ra) (P<.01). The results for bacterial adhesion to gold alloy proved inconclusive. A quantitative comparison indicated no statistically significant differences in pretreatment and posttreatment surface roughness values for lithium disilicate and zirconia specimens. In spite of these similarities, the overall bacterial adherence values for lithium disilicate were significantly greater than those recorded for gold alloy or zirconia (P<.05). Instrumentation of the lithium disilicate and zirconia with the stainless steel curette significantly increased bacterial adhesion compared with the control (P<.05). Conclusions. The results of this investigation indicate that Type III gold alloy exhibited increased surface roughness values after stainless steel curette and prophylaxis cup treatments. Zirconia was less susceptible to bacterial adhesion than lithium disilicate, and greater bacterial adhesion was found for the stainless steel curette than the other instrumentation methods.

Journal of Prosthetic Dentistry, Sep 1, 2012

Statement of problem. Prolonged storage of definitive casts made from Type IV and Type V gypsum p... more Statement of problem. Prolonged storage of definitive casts made from Type IV and Type V gypsum products, especially in an environment of increased temperature and low humidity, may result in contraction. Purpose. The purpose of this study was to evaluate the linear dimensional changes of 5 different high strength stones after exposing them to 2 different storage conditions over a period of 3 weeks. Material and methods. Three Type IV dental stones (Fujirock, Vel-Mix, Suprastone) and 2 Type V dental stones (Hard Rock, Jade Stone) were tested in this study. A circular conical stainless steel die with a diameter of 66 mm and a height of 10 mm was made. Two V-shaped grooves, 38 mm apart, were scribed on the surface of the die for the purposes of measurement. A conical stainless steel ring with a bottom inner diameter of 68 mm and a top inner diameter of 65 mm was also fabricated to fit precisely around the stainless steel die. The dental stone was mixed with water under vacuum and poured under vibration onto the stainless steel die, which was surrounded by the ring. The specimens (n=20) were separated from the stainless steel die 1 hour after pouring. Half of these specimens (control) were stored in a room at 22 ±1°C with relative humidity of 50 ±5%, while the rest of the specimens were placed in a temperature regulating incubator at 40 ±1°C and relative humidity of <20%. The linear dimensional changes were recorded at designated time intervals with a traveling microscope over a 3 week period. Collected data were subjected to a 2-way repeated-measures analysis of variance (ANOVA) (α=.05). Results. The highest expansion values for the specimens in the control group were recorded between 72 and 96 hours. A contraction was noticed thereafter for all specimens, in both groups. No difference in the measurements was registered between the second and third week. ANOVA revealed significant differences (P<.001) among different Type IV and V dental stone products, time, and storage conditions. Conclusions. The highest expansion values for all specimens in the control group were recorded between 72 and 96 hours. The highest expansion values for all specimens in the experimental group were recorded at 24 hours. For all specimens, contraction was noticed up to the 2-week measurements. All factors examined (dental stone, time, storage condition) significantly affected the linear dimensional changes.

Journal of Oral and Maxillofacial Research, Mar 31, 2023

The Journal of Prosthetic Dentistry

Ado klinik bilimler dergisi, Apr 1, 2012

Diş ve implant destekli kron ve köprü protezlerinde kenar uyumu restorasyonun uzun süreli başarıs... more Diş ve implant destekli kron ve köprü protezlerinde kenar uyumu restorasyonun uzun süreli başarısını etkileyen en önemli faktörlerden birisidir. Bu nedenle prepare edilmiş diş veya abutmentin (implant desteği) çevresindeki gingival dokuların retrakte edilerek kenar bitim çizgisinin net ölçüsünün alınması gerekir. Gingival retraksiyon, dişetinin dişten lateral ve vertikal yönlerde geçici olarak uzaklaştırılması işlemidir. Literatürde gingival dokuların retraksiyonu ile ilgili birçok materyal ve yöntem mevcuttur. Diş hekimi en uygun seçimi vakanın durumuna göre yapmalıdır. Bu derlemenin amacı, günümüzde diş ve implant destekli kron ve köprü protezlerinin ölçülerinde kullanılan güncel gingival retraksiyon materyal ve yöntemleri hakkında detaylı bilgi verilmesidir.

Zirkonya tam seramik kron ve kopruler, dis hekimleri ve hastalar tarafindan ustun estetik ve meka... more Zirkonya tam seramik kron ve kopruler, dis hekimleri ve hastalar tarafindan ustun estetik ve mekanik ozellikleri nedeniyle tercih edilmektedir. Zirkonya dogal dis benzeri goruntu saglayan biyouyumlu bir materyaldir. Zirkonya restorasyonlarin dise yapistirilmasinda genellikle rezin simanlar tercih edilmektedir. Zirkonya icerikli seramiklerin rezin simanla baglantisi geleneksel cam seramiklerde kullanilan yontemlerle saglanamamaktadir. Cunku zirkonya, silikadan yoksun, aside karsi direncli ve polikristalin yapida bir seramiktir. Son yillarda, zirkonya ile yapistirici ajanlar arasindaki baglanti arastirmacilarin cok onem verdikleri bir konu olmustur. Baglantiyi arttirmak icin cok sayida yontem gelistirilmis ve literaturde rapor edilmistir. Bu derlemenin amaci, zirkonya-rezin siman baglantisini guclendirmede kullanilan yuzey islemleri hakkinda kapsamli bilgi sunmaktir.

Journal of Oral and Maxillofacial Research

Journal of Dental Sciences, 2021

Background/purpose With the rise of digitalization in dentistry, intraoral scanners and digital i... more Background/purpose With the rise of digitalization in dentistry, intraoral scanners and digital impressions have recently been adopted by many clinicians. The aim of this study was to investigate surface topography of prepared teeth and the accuracy of digital impressions. Materials and methods Twenty mandibular typodonts, containing left first premolar and left first molar abutment teeth manufactured by using CAD/CAM, were used in this study. An intraoral scanner was used to scan each typodont, and each STL file generated was exported in high resolution (Group H), moderate resolution (Group M), and low resolution (Group L). All 60 files were inspected in a 3-D mesh processing software. For each file, the number of triangulation points in the meshwork were obtained for both abutment teeth. Results The measurements obtained from the 3-D mesh processing software revealed that the mean number of triangulation points on the 3-D surface of the abutment teeth (20 premolars + 20 M) were 790,625 ± 98,890 dots in Group H, 592,283 ± 74,881 dots in Group M, and 198,067 ± 19,328 dots in Group L. Significant differences were found between Group H and M (p < 0.05), Group H and L (p < 0.001), and Group M and L (p < 0.01). Conclusion The outcomes of this study reveal that there are strong correlations between the data quality of digital impressions and surface topography of prepared teeth. Therefore, the utilization of STL files in high resolution format is the recommended choice for clinicians engaging in a digital workflow process.

Journal of International Dental Sciences, 2018

Günümüzde implant destekli sabit protezler eksik dişlerin yerine koyulması için yaygın olarak uyg... more Günümüzde implant destekli sabit protezler eksik dişlerin yerine koyulması için yaygın olarak uygulanan tedavi seçeneklerindendir. İmplant destekli sabit protezlerde uygulanan restorasyonlar, siman ve vida retansiyonlu olmak üzere iki tiptedir. 1990'lı yıllardan sonra implant firmalarının siman retansiyonlu üst yapılara uygun abutment üretmesi ile bu tip üst yapılar vidalı sistemlere göre daha fazla kullanılmaktadır. Siman retansiyonlu üst yapılarda retansiyonun sağlanması, implant destekli protezlerin uzun süreli fonksiyonunda önemli rol oynar. Yapıştırıcı ajanlar, sabit protezlerin simantasyonunda kullanılan ve restorasyonun retansiyonunu geçici veya daimi olarak sağlayan dental materyallerdir. Bu materyaller, hem diş destekli hem de implant destekli protezlerde rutin olarak kullanılmasına rağmen her iki protez tipi arasında siman seçimi ve simantasyon prensipleri açısından çeşitli farklar mevcuttur. Bu farkların hekim tarafından bilinmesi ve implant destekli sabit protezlerin yapıştırılması esnasında dikkate alınması restorasyonların biyolojik ve mekanik komplikasyonlar oluşmadan başarılı şekilde kullanılmalarını sağlar. Bu nedenle çalışmamızda, implant destekli sabit protez uygulamalarında kullanılan simanlar ve simantasyon prensipleri ile ilgili güncel ve kapsamlı bilgi verilmesi amaçlanmıştır.

Minerva Dental and Oral Science

Scanning

The aim of this study was to investigate the effects of different surface treatment methods on sh... more The aim of this study was to investigate the effects of different surface treatment methods on shear bond strength between composite resin and different levels of zirconia ceramic. Laser surface-conditioning procedures have been reported as effective method to increase repair bond strength of composite to zirconia ceramics. Detailed information of effects of Er,Cr:YSGG laser treatment with different pulse rates on the zirconia ceramics is lacking in the literature. 120 disc-shaped specimens were prepared including zirconia, veneering ceramic, and 50% veneering ceramic-50% zirconia surfaces. Four different surface treatments were applied to the specimens. These were grinding with diamond bur, sandblasting, and short and long pulse rates of Er,Cr:YSGG laser irradiation. An intraoral ceramic repair kit was used to repair specimens, and shear bond strength was performed on the composite resin to each specimen. The highest mean bond strength was seen in the veneering ceramic surface that...

The International Journal of Oral & Maxillofacial Implants

T ooth extraction accompanies a series of bone remodeling changes that engender attenuation of th... more T ooth extraction accompanies a series of bone remodeling changes that engender attenuation of the buccolingual and apicocoronal bone tissue leading to alveolar ridge resorption. 1 Short endosseous implants have emerged as a minimally invasive alternative to complex corrective/regeneration surgeries for volumetric discrepancies of the alveolar bone. 2 Additional limiting factors such as proximity of the inferior alveolar nerve, pneumatization of the maxillary sinus, etc, impair direct rehabilitation via standard-length implants. Further, complex procedures such as bone augmentation, ridge expansion, and maxillary sinus floor elevation are often associated with increased cost and treatment times as well as higher risk of failure. 3 Osseointegration at the bone-implant interface is collectively dependent on the cellular events occurring in response to the enhanced genetic expression of several factors involved in the healing phases following implant placement, eg, increased osteogenesis and fibrin remodeling owing to the increased expression of osteocalcin, osteoprotegerin, and transforming growth factor β. 4 Unfavorable bone topo graphy and quality could greatly impact the peri-implant cell surface interaction, thereby affecting osseointegration and ultimately implant success. Immediate and early loading of dental implants could counteract the postextraction alveolar ridge bone catabolism. 5

Implant Dentistry, 2017

The aim of the report is to introduce a new software and a new scanner with a noncontact laser pr... more The aim of the report is to introduce a new software and a new scanner with a noncontact laser probe and to present outcomes of computer-aided design and computer-aided manufacturing titanium frameworks using this new software and scanner with a laser probe. Seven patients received 40 implants placed using a 1-stage protocol. After all implants were planned using an implant planning software (NobelClinician), either 5 or 6 implants were placed in each edentulous arch. Each edentulous arch was treated with a fixed dental prosthesis using implant-supported complete-arch milled-titanium framework using the software (NobelProcera) and the scanner. All patients were followed up for 18 ± 3 months. Implant survival, prosthesis survival, framework fit, marginal bone levels, and maintenance requirements were evaluated. One implant was lost during the follow-up period, giving the implant survival rate of 97.5%; 0.4 ± 0.2 mm marginal bone loss was noted for all implants after 18 ± 3 months. None of the prostheses needed a replacement, indicating the prosthesis success rate of 100%. The results of this clinical study suggest that titanium frameworks fabricated using the software and scanner presented in this study fit accurately and may be a viable option to restore edentulous arches.

Texas Dental Journal, Jul 1, 2013

By using traditional casting procedures, accurately fitting of complete-arch frameworks that are ... more By using traditional casting procedures, accurately fitting of complete-arch frameworks that are screwed on multiple implants is difficult to achieve. The introduction of computer-aided design and manufacturing (CAD/CAM) techniques for fabricating custom 1-piece titanium frameworks simplifies this challenge and reduces time spent by the restorative dentist. This report presents a milled titanium complete-arch mandibular framework using a new planning software and a new scanner using non-contact laser probe, which eliminates the need for wax pattern fabrication.

The Journal of Prosthetic Dentistry, 2014

The Journal of Advanced Prosthodontics, 2013

To evaluate the effect of various metal oxides on impact strength (IS), fracture toughness (FT), ... more To evaluate the effect of various metal oxides on impact strength (IS), fracture toughness (FT), water sorption (WSP) and solubility (WSL) of heat-cured acrylic resin. MATERIALS AND METHODS. Fifty acrylic resin specimens were fabricated for each test and divided into five groups. Group 1 was the control group and Group 2, 3, 4 and 5 (test groups) included a mixture of 1% TiO 2 and 1% ZrO 2 , 2% Al 2 O 3 , 2% TiO 2 , and 2% ZrO 2 by volume, respectively. Rectangular unnotched specimens (50 mm × 6.0 mm × 4.0 mm) were fabricated and droptower impact testing machine was used to determine IS. For FT, compact test specimens were fabricated and tests were done with a universal testing machine with a cross-head speed of 5 mm/min. For WSP and WSL, discshaped specimens were fabricated and tests were performed in accordance to ISO 1567. ANOVA and Kruskal-Wallis tests were used for statistical analyses. RESULTS. IS and FT values were significantly higher and WSP and WSL values were significantly lower in test groups than in control group (P<.05). Group 5 had significantly higher IS and FT values and significantly lower WSP values than other groups (P<.05) and provided 40% and 30% increase in IS and FT, respectively, compared to control group. Significantly lower WSL values were detected for Group 2 and 5 (P<.05). CONCLUSION. Modification of heat-cured acrylic resin with metal oxides, especially with ZrO 2 , may be useful in preventing denture fractures and undesirable physical changes resulting from oral fluids clinically. [ J Adv Prosthodont 2013;5:241-7]

Journal of Oral Rehabilitation, 2009

The Journal of Contemporary Dental Practice, 2013

Although, dental implants have been a predictable option to support several types of restorations... more Although, dental implants have been a predictable option to support several types of restorations, mechanical problems are not uncommon. Retaining and abutment screw loosenings/fractures are one of the most common technical problems. To present a step-by-step technique in order to remove a broken locater abutment screw fragment. A 56-year-old, edentulous man with a fractured locator abutment screw in an implant was referred to our clinic from a private practice. His dentist placed a narrow platform locator abutment onto a regular platform implant and the fracture occurred. Attempts to remove the fractured fragment using a periodontal probe and a manual screw removal driver were unsuccessful. This clinical report presents a situation in which a fractured locater abutment screw fragment was successfully removed using an implant repair kit. A fractured locater abutment screw fragment was successfully removed using an implant repair kit including drills, drill guides and tapping instruments. To avoid similar complications, it is recommended to use appropriate manufacturer specified torque values in conjunction with compatible restorative components. Retaining and abutment screw loosenings/fractures are one of the most common mechanical problems associated with the implant components. This clinical report showed how to remove a broken screw fragment using proper armamentarium and technique, which might help clinicians eliminate similar problems.