Necla Demir

Surface Roughness and Morphologic Changes of Zirconia Following Different Surface Treatments

OBJECTIVE The aim of this study was to evaluate the roughness and morphology of zirconia after air abrasion and erbium:yttrium-aluminum-garnet (Er:YAG) laser application of different intensities. BACKGROUND DATA Although surface roughness is important to obtain micromechanical retention, it is unclear which surface treatment is most appropriate for zirconia. METHODS Fifty sintered zirconia specimens were divided into five groups (n=10). The following treatments were applied: control, Er:YAG laser irradiation with different energy intensities (200, 300, and 400 mJ), and air abrasion with aluminum oxide (Al(2)O(3)) particles (110 μm). Morphologic changes after surface treatments were examined in microscope analyses. Then, the surface roughness (Ra in μm) of the specimens was evaluated using a surface texture measuring instrument. Roughness data were analyzed using one-way analysis of variance (ANOVA) and Tukeys honestly significant difference (HSD) test (p=0.05). RESULTS Results of microscope analyses revealed changes in surface morphology after surface treatments, including the formation of rare pits in the 400 mJ laser group and the formation of microretentive grooves in the air abrasion group. According to the results of the statistical analysis, the mean surface roughness value for the air abrasion group was significantly higher than that of the other groups (p<0.001). Except for the air abrasion group, there were no statistically significant differences within other groups (p>0.05). CONCLUSIONS According to the results of the statistical and microscopic analyses, 400 mJ Er:YAG laser energy or air abrasion can be used to obtain micromechanical retention prior to luting; however, air abrasion is the most effective surface treatment method.

Evaluation of the marginal fit of full ceramic crowns by the microcomputed tomography (micro-CT) technique.

Objective: To evaluate the marginal gap (MG) and absolute marginal discrepancy (MD) of full ceramic crowns with two finish line designs, shoulder and chamfer, using microcomputed tomography (micro-CT) before and after cementation. Materials and Methods: Sixty extracted human maxillary premolar teeth were divided into two groups based on the finish line design: Group I: 90° shoulder and Group II: 135° chamfer. The specimens were further grouped based on the type of full ceramic crown they received: Group A: Feldspathic Cerec inLab ceramic system, Group B: Cerec inLab aluminum oxide ceramic system and Group C: Lithium disilicate press ceramic system. Before cementation, five crowns from each group were scanned using micro-CT in two sections, sagittal and coronal, to determine the MG and MD values for four regions of the crown (sagittal buccal, sagittal lingual, coronal mesial and coronal distal). After cementation and thermal cycling, the scanning was repeated. Measurements were obtained from 10 points for each region, 80 points totally, to evaluate the MG and MD values. Files were processed using NRecon and CTAn software. Results were statistically analyzed using one- and two-way ANOVA and Tukey HSD tests (P = 0.05). Results: Full ceramic systems showed clinically acceptable marginal adaptation values. The Feldspathic Cerec inLab ceramic system generally presented the lowest variance, except in the MG values of the coronal mesial region. The MG and MD values of all ceramics increased significantly after cementation, except in the shoulder preparation design (sagittal buccal region) for MG and in the chamfer preparation design (sagittal lingual region) for MD values. Conclusions: Full-ceramic crowns showed clinically acceptable marginal adaptation values. The Feldspathic Cerec inLab ceramic system (Vitablocs Mark II) generally presented the lowest variance when compared with the other ceramics, except for the MG values on the mesial surface of the coronal section.

Mechanical properties of zirconia after different surface treatments and repeated firings.

PURPOSE This study investigated the influence of surface conditioning procedures and repeated firings on monoclinic content and strength of zirconia before cementation. MATERIALS AND METHODS Sintered bar-shaped zirconia specimens were subjected to no surface treatment (control), air abrasion, or grinding (n=21). Their roughness was evaluated using a profilometer, and microscope analysis was performed on one specimen of each group. Then, 2 or 10 repeated firings (n=10) were executed, the monoclinic content of specimens was analyzed by X-ray diffraction, and a three-point flexural strength test was performed. Surface roughness values were compared using one-way analysis of variance (ANOVA) and Tukey honestly significant difference (HSD) tests, the monoclinic content values were tested using Kruskal-Wallis and Mann-Whitney U tests, and the flexural strength values were tested using two-way ANOVA and Tukey HSD tests (P=.05). Spearmans correlation test was performed to define relationships among measured parameters. RESULTS Surface-treated specimens were rougher than untreated specimens and had a higher monoclinic content (P<.005), and the relationship between roughness and monoclinic content was significant (P<.000). Neither surface treatment nor firing significantly affected the flexural strength, but Weibull analysis showed that for the air-abraded samples the characteristic strength was significantly lower after the 10th firing than after the 2nd firing. CONCLUSION After firing, a negligible amount of monoclinic content remained on the zirconia surfaces, and rougher surfaces had higher monoclinic contents than untreated surfaces. Multiple firings could be performed if necessary, but the fracture probability could increase after multiple firings for rougher surfaces.

Implant-retained auricular prosthesis.

Auricular defects may result from congenital malformations, injuries from motor vehicle crashes, trauma, or tumor resections. An auricular prosthesis was fabricated for a patient who had an injury from a motor vehicle crash. Extraoral implants and bar-and-clip retention for the proper connection of the auricular prosthesis to implant were used. This prosthesis was acceptable to the patient because of excellent support, retentive abilities, and the patients appearance.

Implant-retained nasal prosthesis

Malignant tumors of the nose occasionally require rhinectomy. Facial defects can cause not only functional problems but also some serious physchological problems that could cause the individual to avoid social contact. In view of this, the first aim of maxillofacial rehabilitation should be solving esthetic problems. Implant retained prostheses can give good esthetic results. Predictable biomechanical retention of nasal prostheses can be achieved using osseointegrated implants and intra-oral and craniofacial implants have been used previously. These prostheses are tissue compatible, simple in design and easy to place, can be worn independently of spectacles and in the majority of cases can be provided soon after surgical excision. In this case report, a nasal prosthesis was fabricated for a patient who lost his nose due to the basal cell carcinoma. Extra-oral implants and magnet retention for the proper connection of the nasal prosthesis were used. This prosthesis was acceptable for the patient because of excellent support, retentive abilities and the patient′s appearance.

Intranasal Midazolam May Prevent Gagging Reflex: a Case Report

ABSTRACT Background Gagging can become a conditioned response that makes dental treatment difficult or impossible for both the individual and the dentist. The aim of this study is to report a 50 year old female and two children (15 and 11 years old) with exaggerated gag reflex referred to Faculty of Dentistry of Selçuk University. Methods During obtaining records, taking impression procedure was elicited the patients’ hypersensitive gagging reflex. Therefore, it was decided to administer intranasal midazolam to facilitate the taking of accurate dental impressions. After given verbal information about the procedure, 2.5 mg intranasal midazolam (Demizolam, Dem Medikal, Istanbul) were applied incrementally in both nostrils. Results Five minutes later; patients had no gagging reflex and allowed the clinician to take satisfying impressions. No serious adverse effects were observed and the patients remained cooperative during the entire procedure which was completed to the full satisfaction of all involved. The short absorption time and the fast relief process of anaesthetics transferred to the systemic circulatory system are important advantages of nasal application. Conclusions Intranasal midazolam may be very useful for the treatment of gag reflex probably effecting on the depression of upper airway reflex sensitivity.

Effect of new laser type on shear bond strenght of acrylic teeth to denture base

Background: The aim of this study is to examine the Shear Bond Strength (SBS) to repairing acrylic or acrylic artificial teeth which applied to four different surface treatments. Materials and Methods: Fourty molar acrylic denture teeth were ground on the ridge lap area with a water sand paper to provide a uniform surface for bonding. Acrylic teeth embedded in cold cured acrylic resin and specimens were randomly seperated into four roups (n = 10), according to the urface treatments applied; 1-Control, 2-Air abrasion, 3-Er-YAG laser and 4-Femtosecond laser. The cold cured acrylic resin (Vertex self curing) was then mixed according to the manufacturer′s instructions and injected into the Teflon tubes with an internal diameter and height of 4 and 3 mm, respectively. The SBS of the acrylic denture teeth was evaluated using a universal testing machine. Acrylic denture teeth bonding areas were observed with a stereomicroscope to identify the mode of fracture. Results: The data were evaluated statistically Kruskal Wallis one-way analysis of variance (ANOVA) and Mann Whitney U-tests with bonferronni correction. There were no statistically significant difference of mean bond strengths for shear tests among control, Er-YAG and Femtosecond laser application groups. But the highest SBS values were found for air abrasion groups. Conclusion: A quick and simple air abrasion surface treatment technique could be an effective option for denture repair.

Dentoalveolar defektli hastaların protetik rehabilitasyonunda farklı üst yapı seçenekleri: İki olgu sunumu

Dentoalveolar defektlerin olusum nedenleri dogumsal, gelisimsel ve kazanilmis olmak uzere uc grupta toplanabilir ve hastalarda estetik, fonetik ve fonksiyonel problemlere neden olabilirler. Tedavide multidisipliner yaklasim ve vakaya ozgu bir planlama gerekmektedir. Bu olgu sunumunda dentoalveolar defekte sahip iki hastanin farkli tutucu sistemlerine sahip dental implant destekli protezler ile protetik rehabilitasyonu anlatilmaktadir. Klinik ve radyografik muayene sonrasinda hastalara implant destekli sabit protezler, dis destekli sabit protezler ve hareketli protezlerden olusan tum tedavi secenekleri anlatildi. Birinci hastada mandibular sol taraftaki defekt, CAD-CAM ile uretilen siman tutuculu kisiye ozel abutmentlar kullanilarak restore edilirken; ikinci hastada maksiller sol taraftaki defekt vida tutuculu multi-unit abutmentlar kullanilarak restore edilmistir. Hastalarin estetik ve fonksiyonel beklentileri tedavi sonrasinda basarili bir sekilde karsilanmistir. Oral hijyen konusunda bilgilendirilen hastalarin 1 haftalik kontrollerinde herhangi bir komplikasyona rastlanilmamistir ve 3 ay sonra tekrar kontrole cagrilmistir.

Shear bond strength of a novel porcelain repair system for different computer-aided design/computer-assisted manufacturing ceramic materials

Objectives: The purpose of this study was to compare the shear bond strength of a novel repair system, Nova Compo SF with Ceramic Repair, Ivoclar, to computer-aided design/computer-assisted manufacturing (CAD/CAM) restorative materials (IPS e.max CAD and Empress CAD). Materials and Methods: The specimens of each CAD/CAM restorative material were randomly divided into two subgroups of nine specimens, using one of two repair systems. All specimens were etched with hydrofluoric acid and rinsed under a water spray for 10 s, then air-dried for 10 s. Next, repair systems were applied according to the manufacturers instructions. All specimens were stored in distilled water at 37°C for 24 h and then additionally aged for 5000 thermal cycles. A shear bond strength test was performed using a universal testing machine. Each fracture type was examined under a stereomicroscope at ×12.5 magnification. A two-way ANOVA test was used to detect significant differences between the CAD/CAM restorative materials and the composite repair systems. Subgroup analyses were performed using Tukeys honest significant difference. Results: No statistically significant differences were observed between the repair systems (P = 0.9). The bond strength values from Empress CAD were statistically higher than those from e.max CAD (P < 0.05). Conclusions: Within limitations, SuperFlow may be an alternative to the ceramic repair materials we routinely used in the clinic. Empress CAD can be preferable to e.max CAD in terms of esthetically suitable clinical indications.

REHABILITATION OF MAXILLECTOMY CASE WİTH CONVENTIONAL RETAINED OBTURATOR PROSTHESIS: A CASE REPORT

ABSTRACT Maxillary resection performed for removal of the tumor mass, leads to esthetic, phonetic, functional and important psychological problems for the patient. The primary aim of prosthetic rehabilitation is to close the maxillary defect and eliminate such problems by use of different bulb designs. An obturator is a treatment option for the defects after maxillary tumor surgery . In this article, rehabilitation with hollow bulb obturator prosthesis was explained for a patient subjected to maxillary resection because of tumor mass. Keywords: Maxillary defect, obturator, hollow bulb, prosthetic rehabilitation MAKSILLER REZEKSIYONUN GELENEKSEL TUTUCULU OBTURATOR ILE REHABILITASYONU: VAKA RAPORU OZ Tumor kitlesini ortadan kaldirmak icin yapilan maksiler rezeksiyon hastalar icin estetik, fonetik, islevsel ve onemli psikolojik sorunlara yol acar. Protetik rehabilitasyonun oncelikli amaci farkli bulb dizaynlarini kullanarak maksiller defekti ve buna bagli bazi problemleri ortadan kaldirmaktir. Obturatorler, maksiller tumor cerrahisi sonrasi olusan defektler icin bir tedavi yontemidir. Bu makalede, tumor kitlesi nedeniyle maksiller rezeksiyon yapilan bir hastanin hollow bulb obturator protez ile rehabilitasyon anlatilmaktadir. Anahtar Kelimeler: Maksiller defekt, obturator, hollow bulb, protetik rehabilitasyon