Protetik Diş Tedavisi Ana Bilim Dalı Koleksiyonu

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https://hdl.handle.net/20.500.12491/73

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Comparison of the light transmission of new generation monolithic zirconia materials and lithium disilicate
(Mosher & Linder, Inc, 2023) Köseler, Ege; Değirmenci, Kübra; Sarıdağ, Serkan
Purpose: To compare the effects of different thicknesses of ceramic veneering on the light transmission of various monolithic zirconia and lithium disilicate materials used in esthetic restorations. Methods: Zirconia (i.e., Katana UT, Katana HT, Prozir Diamond, Prozir HT, and Zenostar MO) and lithium disilicate specimens (i.e., Emax HT and Emax MO) were prepared at thicknesses of 0.5 mm, 0.8 mm, and 1.2 mm. Additionally, 0.8 mm-thick specimens and 0.3 mm-thick ceramic veneer were prepared for veneering groups. The total transmittance of light values were measured using a spectrophotometer. The light transmission values were analyzed using the Kruskal-Wallis and the post-hoc Dunnett tests (alpha= 0.05). Results: The Emax HT group defined significant differences from all groups (P< 0.05) at all thicknesses. The mean total transmittance of light ranged from 5.53% to 19.55%. There was no significant difference between the Katana UT and Prozir Diamond groups at the 0.5 mm, 0.8 mm, and 1.2 mm thicknesses (P> 0.05).
Evaluation of the effects of different composite materials and surface roughening techniques in bonding attachments of clear aligner on monolithic zirconia
(Wiley, 2023) Arslan, Semiha; Kılınç, Hamiyet
Objective: The aim of this study is to evaluate the bond strengths of two different composite types used in the production of clear aligner attachments on monolithic zirconia with three different surface roughening processes.Materials and Methods: Packable composite Filtek Z250 was used in one group (PC-G) and flowable composite Filtek Supreme Ultra Flowable was used in the other group (FC-G). PC-G and FC-G groups were also divided into three subgroups as diamond bur+silane (Group 1), 50 mu m aluminium oxide (Al2O3) sandblasting+silane (Group 2) and 110 mu m Al2O3 sandblasting+silane (Group 3). Scanning electron microscopy (SEM) analysis was performed. Clear aligner attachments were bonded to the monolithic zirconia specimens. Shear bond strength (SBS) values were measured. Statistical analysis was performed using two-way ANOVA and post-hoc Tukey's tests (P < .05).Results: The highest SBS value was found in PC-G sandblasted with 110 mu m Al2O3 (P <= .001). The etching method with 110 mu m sandblasting showed high SBS values in both composite types. The lowest SBS value gave FC-G in diamond bur roughening (P <= .001).Conclusions: For the bonding of clear aligner attachments on monolithic zirconia, roughening with 110 mu m particle size sandblasting and the choice of packable composite could be recommended in terms of retention.
Evaluation of the effects of different surface modification methods on the bond strength of high-performance polymers and resin matrix ceramics
(Springer Heidelberg, 2022) Tosun, Büşra; Yanıkoğlu, Nuran
Objectives The purpose of this in vitro study was to investigate the effects of various surface treatment methods on the shear bond strength of self-adhesive resin cement to polymer-infiltrated materials. Materials and methods One hundred twenty-eight polymer-infiltrated specimens (n = 32) for four different computer aided design-computer-aided manufacturing (CAD-CAM) materials, polyether ether ketone (PEEK) (PE), polyether ketone ketone (PEKK) (PK), composite resin nanoceramic (Cerasmart) (CS), and polymer-infiltrated ceramic network (PICN) (VITA ENAMIC) (VE) were milled from CAD-CAM blocks. They were divided into two groups (n = 16) in terms of surface treatments: airborne-particle abraded (AA) or silica-coated (SC) and two subgroups (n = 8) according to adhesive application or no adhesive. The surface roughness, contact angle, and shear bond strength (SBS) values of specimens were measured. Data were analyzed with Shapiro-Wilk test, the generalized linear models' method, and Bonferroni corrected t test (alpha < 0.05). Results No statistically significant differences were found between the groups in terms of surface roughness and SBS values (P > 0.05). A statistically significant effect of the main adhesive interaction on the bond strength was found independent of the material and surface treatments (P < 0.001). While the average bond strength of the non-adhesive was 4.9 MPa, the average of the adhesive applied was 9.1 MPa. On the other hand, there is a statistically significant difference between the means of the contact angle values (P < 0.001). While the highest mean contact angle value was 117.1 +/- 14.8 degrees obtained from the non-adhesive PK in the AA group, the lowest mean contact angle value 22.6 +/- 4.3 degrees was obtained from the VE without adhesive in the SC group. Conclusions Roughness and SBS values were similar between groups after surface treatments. Adhesive application increased the SBS values. Surface treatments were found to have an effect on the contact angle.
Evaluation of quality of life and oral hygiene attitudes of individuals using dental prostheses during the COVID-19 pandemic
(Mosby-Elsevier, 2021) Değirmenci, Kübra; Kalaycıoğlu, Oya
Statement of problem. The COVID-19 pandemic impacted every area of our lives, including delaying urgent dental care. However, studies evaluating how patients using dental prostheses have been affected by the pandemic are lacking. Purpose. The purpose of this study was to investigate how patients using different types of dental prostheses were being affected by the COVID-19 pandemic. Material and methods. A total of 129 randomly selected individuals from among those who had been examined in the same clinic before the COVID-19 outbreak were included in the study. The study participants were divided into 4 groups according to their type of prosthesis: complete dentures, implant-retained removable dentures, tooth-supported fixed partial dentures, and implant-supported fixed partial dentures. The Oral Health Impact Profile (OHIP-14) questionnaire was implemented by telephone interviews with the study participants, who were also asked about their concerns and steps made regarding prosthetic hygiene during the COVID-19 pandemic. Data were evaluated by the Kruskal-Wallis and post hoc Dunn tests, and multivariate logistic regression analysis with forward selection was carried out to identify predictors of the oral health-related quality of life (OHRQoL) status (alpha=.05). Results. OHIP-14 total scores did not vary significantly among the groups (P>.05). When the domain scores of OHIP-14 were considered separately, the analysis revealed that the implant-retained removable denture group had significantly poorer functional limitations when compared with the tooth-supported fixed partial denture (P=.005) and implant-supported fixed partial denture (P=.031) groups. The results of the multivariate logistic regression analysis indicated a statistically significant association between OHRQoL during the COVID-19 pandemic and the frequency of tooth or denture cleaning (1 time a day versus less than 1 time a day: P=.011; 2-3 times a day versus less than 1 time a day: P=.032). Conclusions. All prosthesis users exhibited increased interest in dental hygiene and an increase in the frequency of prosthesis cleaning during the pandemic. Furthermore, the study determined that the frequency of tooth or denture cleaning was associated with significantly improved OHRQoL during the time of the COVID-19 pandemic. Among the denture groups, those treated with implant-retained removable dentures had the poorest functional limitation in terms of OHRQoL, which can be linked to postponement of routine maintenance appointments. Therefore, providing all patients with scientifically sound information on prosthetic care during a pandemic would be highly beneficial.
Effect of sintering and aging processes on the mechanical and optical properties of translucent zirconia
(Mosby-Elsevier, 2021) Kılınç, Hamiyet; Şanal, Fatma Ayşe
Statement of problem. Sintering holding times and aging conditions may affect the optical, mechanical, and structural properties of polychromatic multitranslucent zirconia. However, a consensus on the ideal sintering condition for this material is lacking. Purpose. The purpose of this in vitro study was to investigate the effect of different sintering holding and autoclave aging times on the flexural strength (FS), grain size, and translucency parameter (TP00) of a translucent zirconia. Material and methods. Sixty bar-shaped and 60 rectangular-shaped specimens were prepared from computer-aided design and computer-aided manufacturing (CAD-CAM) zirconia blocks and split into 2 groups to be sintered at 1550 degrees C for different holding times (regular: 2 hours, prolonged: 5 hours). The specimens were then divided into 3 subgroups and subjected to aging processes (control, aging for 60 minutes, aging for 120 minutes). FS values were obtained by using a 3-point bend test and Weibull analysis was conducted. Grain size evaluations were performed by using scanning electron microscope (SEM) observations. TP00 was measured with a spectrophotometer. Statistical evaluation included the Kolmogorov-Smirnov, 2-way ANOVA, and Tukey HSD tests (alpha=.05). Results. The sintering procedure, aging, and their interaction significantly influenced the TP00 (P<.05). FS values and grain sizes were affected by aging only (P<.001). Both aging times resulted in reduced FS and increased grain sizes. Prolonged sintering in combination with 120 minutes of aging negatively affect the TP00 scores (P<.05). Conclusions. FS values were similar under regular and prolonged sintering. Prolonged sintering led to a decrease in translucency after 120 minutes of aging. Steam autoclave aging can affect the optical and mechanical properties of translucent zirconia.
Evaluation of the relationship between oral health, chewing ability, and degree of disease in alzheimer-type dementia patients
(Güneş Kitabevi Ltd. Şti., 2021) Değirmenci, Kübra; Türel, Canan Akünal
Introduction: The objective of this study was to investigate the relationship among oral health attitudes, chewing efficiency, and the degree of disease in patients with Alzheimer-type dementia. Materials and Methods: Thirty-nine patients with Alzheimer-type dementia as the study group and 38 cognitively healthy participants as the control group were registered for this cross-sectional study. The participants' demographics and basic clinical features, oral health attitudes, and chewing efficiency scores were recorded for the analysis, and then the evaluation was done comparatively between the groups. Results: A total of 77 participants were included the study. The mean ages of the healthy (control) and Alzheimer-type dementia (study) groups were determined as 69.28 +/- 3.31 and 67.10 +/- 2.11 years, respectively. The chewing scores of the healthy and Alzheimer-type dementia groups were compared, and the scores of Alzheimer-type dementia group showed significantly lower values than the scores of the healthy group (p<0.001). Not using dentures despite tooth loss for both the mandibula and maxilla was found to be significantly higher in the Alzheimer-type dementia group than it was in the healthy group (p<0.001). Conclusion: The study showed a negative correlation between oral health attitudes, chewing efficiency, and the degree of disease in patients with Alzheimer-type dementia. Poor chewing efficiency may be related to the progress of Alzheimer-type dementia. Healthy chewing functions can support cognitive abilities. Thus, prosthetic treatment can be considered a protective factor against Alzheimer-type dementia.
Evaluation of the effects of finish line type and width on the fracture strength of provisional crowns
(Springer, 2021) Karaman, Tahir; Eser, Bekir; Altıntaş, Eyyüp; Atala, Mustafa Hayati
This study aimed to investigate the impacts of finish line type and width on the fracture resistance of provisional crowns, and to determine the suitable type of crown material to use for that purpose. Chamfer and rounded shoulder preparations were done with stainless steel master models with a width of 0.6 mm and 1.0 mm and a total convergence angle of 6 degrees. The provisional crowns were obtained using computer-aided design/computer-aided manufacturing (CAD/CAM) polymethyl methacrylate (PMMA) material in the mandibular left first molar. From the obtained molar tooth, a silicon mold was used to obtain the provisional crowns from the CAD/CAM PMMA, bis-acrylic resin, and self-curing composite materials. The lowest fracture strength was found in the bis-acrylic resin group made using the rounded shoulder preparation with a width of 0.6 mm (699 N). The highest fracture strength was found in the CAD/CAM PMMA group made using the rounded shoulder preparation with a width of 1 mm (1339 N). The fracture strength is higher for CAD/CAM PMMA than the other provisional crown materials; thus, it is recommended that this material be used in provisional crown restorations due to its other advantages.
Effect of different surface treatments on the shear bond strength of luting cements used with implant-supported prosthesis: An in vitro study
(Korean Acad Prosthodontics, 2020) Değirmenci, Kübra; Sarıdağ, Serkan
PURPOSE. The aim of this study was to investigate the shear bond strength of luting cements used with implant retained restorations on to titanium specimens after different surface treatments. MATERIALS AND METHODS. One hundred twenty disc shaped specimens were used. They were divided into three groups considering the surface treatments (no treatment, sandblasting, and oxygen plasma treatment). Water contact angle of specimens were determined. The specimens were further divided into four subgroups (n=10) according to applied cement types: polycarboxylate cement (Adhesor Carbofine-AC), temporary zinc oxide free cement (Temporary Cement-ZOC), non eugenol provisional cement for implant retained prosthesis (Premier Implant Cement-PI), and non eugenol acrylic-urethane polymer based provisional cement for implant luting (Cem Implant Cement-CI). Shear bond strength values were evaluated. Two-way ANOVA test and Regression analysis were used to statistical analyze the results. RESULTS. Overall shear bond strength values of luting cements defined in sandblasting groups were considerably higher than other surfaces (P<.05). The cements can be ranked as AC > CI > PI > ZOC according to shear bond strength values for all surface treatment groups (P<.05). Water contact angles of surface treatments (control, sandblasting, and plasma treatment group) were 76.17 degrees +/- 3.99, 110.45 degrees +/- 1.41, and 73.80 degrees +/- 4.79, respectively. Regression analysis revealed that correlation between the contact angle of different surfaces and shear bond strength was not strong (P>.05). CONCLUSION. The retentive strength findings of all luting cements were higher in sandblasting and oxygen plasma groups than in control groups. Oxygen plasma treatment can improve the adhesion ability of titanium surfaces without any mechanical damage to titanium structure.
Could microwave glazing be considered as an alternative to conventional surface finishing methods of ceramic materials in terms of color stability?
(Quintessence Publishing Co Inc, 2020) Şanal, Fatma Ayşe; Kurt, Murat
Purpose:To examine microwave heating for the purpose of ceramic glazing as an alternative to conventional methods in terms of color stability. Materials and Methods: Thirty disk-shaped specimens (11 x 2 mm) of VITA VM 9, VITA VM 13, VITA VMK 95, and IPS e.max Ceram veneers were prepared (n = 30 each). The specimens were further divided into three subgroups according to surface finishing procedure (polishing, conventional oven glazing, or microwave glazing [n = 10 each]). The related surface finishing procedure was applied according to the manufacturers' instructions. Color differences (Delta E) of the ceramic samples stored in a coffee solution at 37 degrees C for 168 hours were determined using spectrophotometry. Data were analyzed using two-way ANOVA. The group differences were analyzed using Tukey HSD test. Results: Microwave-glazed specimens showed similar Delta E values to conventionally glazed specimens for the tested ceramics (P>.05). Polished specimens showed higher Delta E values than glazed specimens for the investigated ceramic materials, and the difference was significant for VITA VMK 95 and Vita VM9 (P <=.05). Conclusion: Microwave glazing has the advantage of decreasing glazing time to a few minutes and could be considered as an alternative method to conventional oven glazing and polishing with respect to color stability.
Effect of shade and sintering temperature on the translucency parameter of a novel multi-layered monolithic zirconia in different thicknesses
(Wiley, 2020) Şanal, Fatma Ayşe; Kılınç, Hamiyet
Objective The objective of the present research was to evaluate the effect of sintering temperatures (1350 degrees C, 1450 degrees C, and 1600 degrees C) of a novel multi-layered esthetic zirconia material (Katana 12Z/STML) on the grain sizes and on the translucency parameters (TP00) for 2 different shades (A2-A3) and 2 different thicknesses (1-1.5 mm). Material and Methods A total of 120 non-sintered specimens were randomly divided into three subgroups according to sintering temperatures. The TP00 and grain sizes of the sintered specimens were calculated. Statistical analyses were performed using 3-way ANOVA, 1-way ANOVA, and Tukey's post hoc tests. Results TP00 increased 1.2 to 1.5 times as the specimen thickness decreased from 1.5 to 1 mm (P <= .05). The lowest TP00 values were recorded for sintering at 1350 degrees C for the investigated thicknesses and shades (P <= .05). The interaction of sintering temperature and shade was significant (P <= .05). Grain sizes were ordered according to sintering temperature as 1350 degrees C < 1450 degrees C < 1600 degrees C (P <= .05). Conclusions TP00 values decreased with the increase in the thickness of the monolithic zirconia. The sintering temperatures and their interaction with shade significantly affected TP00 values. The grain size increased with increasing sintering temperature. Clinical significance The translucency of a novel multi-layered monolithic zirconia increased with higher sintering temperatures and lower thickness. The grain size increased with the increase in the sintering temperature. The sintering temperature of 1600 degrees C led to a significant change in translucency for shade A3.
Do different sintering conditions influence bond strength between the resin cements and a currently used esthetic zirconia?
(Taylor & Francis Ltd, 2020) Şanal, Fatma Ayşe; Kılınç, Hamiyet
The present research aimed to evaluate the effect of sintering temperature (1300 degrees C, 1400 degrees C and 1600 degrees C) on short-term and long-term SBS values (SBS(1)and SBS2, respectively) as well as grain size and surface roughness of a novel multi-layered monolithic zirconia material (Katana STML). One hundred and eighty-six samples (N = 186) of monolithic zirconia were prepared and randomly divided into three groups (n = 62) according to the final sintering temperatures. Two samples from each group were taken before and after sandblasting for scanning electron microscopy (SEM) examination. The surface roughness (Ra) values were determined. Sixty samples for each group were divided into three subgroups according to the resin cement (n = 20) and luting procedures were performed. Half of the specimens for each subgroup (n = 10) were non-aged, while the other half (n = 10) were aged before shear bond strength test (SBSt). One-way analysis of variance (ANOVA), two-way ANOVA and independent samplesT-test were used to analyse the data. The sintering temperature, resin cement and their interaction were significant (p <= .05) for both aged and non-aged samples. The grain sizes and Ra values of monolithic zirconia significantly increased by the increase of sintering temperature (p <= .05). The aging significantly reduced SBS values (p <= .05). Sintering temperature and resin cement affected both SBS(1)and SBS(2)values between resin cement and monolithic zirconia (p <= .05). Application of 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) containing primer revealed an increase in long-term SBS values in response to the increase in sintering temperature.
Evaluation of effectiveness of self-adhesive composites for amalgam repair with or without alloy primer, in terms of shear bond strength
(Univ Costa Rica, Fac Odontologia, 2020) Şanal, Fatma Ayşe; Güler, Derya
Purpose: The purpose of the present research was to evaluate the effectiveness of self-adhesive composites in amalgam repair as time-saving alternatives to universal bonding-universal composite materials, with or without the usage of Alloy Primer in terms of shear bond strength. Materials and Methods: Forty-two disc-shaped amalgam samples were prepared by condensing into 6x2 mm holes in acrylic resin blocks, sandblasted with 50 mu m Al2O3 and randomly divided into 6 groups according to repair material [Constic (Group C), Fusio Liquid Dentin (Group FLD), Universal bonding+Universal composite (Group Control), Alloy Primer+ Constic (Group APC), Alloy Primer+ Fusio Liquid Dentin (Group APFLD), Alloy Primer+ Universal bonding+Universal composite (Group APControl)]. After shear bond strength test, the fracture modes were determined under a digital microscope. Statistical analysis was performed using one-way analysis of variance and Tukey's post hoc test. Results: The highest shear bond strength values were obtained for Fusio Liquid Dentin, among the three repair materials when Alloy Primer was not applied (p<0.05). Usage of Alloy Primer increased shear bond strength values of the investigated repair materials to amalgam, except Fusio Liquid Dentin. Conclusion: Within the limitations of the present research, it can be concluded that; the investigated self- adhesive composite materials could be time-saving alternatives to the Universal bonding+Universal composite for the purpose of amalgam repair, in terms of shear bond strength. The clinicians could prefer Fusio Liquid Dentin self-adhesive composite material without Alloy Primer application for the purpose of amalgam repair in non-cooperative patients.
Effect of different denture base cleansers on surface roughness of heat polymerised acrylic materials with different curing process
(Univ Costa Rica, Fac Odontologia, 2020) Değirmenci, Kübra; Atala, Mustafa Hayati; Sabak, Canan
Avoiding biofilm formation on dentures is associated with maintaining the surface properties of acrylic-based dentures. The aim of the study is to investigate the effects of two different cleaning agents (Corega and Klorhex 0.2% chlorhexidine gluconate) on surface roughness of the denture regarding efficacy of curing procedures. A total of sixty disc-shaped specimens were prepared with two different methods as long and short curing processes. The specimens were divided into subgroups according to the immersion solutions (distilled water, Corega tablet group and Klorhex 0.2% chlorhexidine gluconate group) (n=10). The samples were kept in a solution for 8 hours per day during a month. The average Ra-1 (before exposure to the cleanser agent) and Ra-2 (after exposure to the cleanser agent) of each sample was measured. A two-way ANOVA and post hoc Tukey test was used for statistical analysis. The solutions significantly increased the Ra values in both acrylic groups (p<0.001). While the effect of the distilled water group was significantly lower than Corega and Klorhex in the long-term curing group (p<0.05), no significant difference was found in the short-term curing group (p>0.05). The long-term curing time is highly effective in decreasing the surface roughness of the acrylic base material.
Evaluating ceramic repair materials in terms of bond strength and color stability
(Quintessence Publishing Co Inc, 2020) Şanal, Fatma Ayşe; Kılınç, Hamiyet
Purpose: To evaluate the shear bond strength (SBS) and color stability (Delta E) of four ceramic veneers (VITA VM 9; VITA VM 13; VITA VMK 95; and IPS e.max Ceram) following repair with three different self-adhesive composite resins (Fusio Liquid Dentin; Constic; and Vertise Flow) and BISCO Intraoral Repair Kit + Filtek Supreme (BC + FS). Materials and Methods: A total of 96 specimens were prepared per ceramic material, and each ceramic group was divided into subgroups according to testing method (32 specimens for color stability analysis and 64 specimens for SBS testing). Delta E and SBS (SBS1 = non-aged, SBS2 = thermally aged) values of the repaired specimens were calculated. One specimen from each of the thermally aged groups was investigated under scanning electron microscopy (SEM). Two-way ANOVA was used to analyze the mean Delta E, SBS1, and SBS2 values. The differences between SBS1 and SBS2 values were analyzed using independent-samples t test. Results: The lowest Delta E values were calculated for Constic (P <= .05). The SBS2 values among all groups were lower than the SBS1 values (P <= .05). The lowest SBS2 values were observed for Vertise Flow (2.3 +/- 1.47 MPa) (P <= .05) and were below the acceptable limit of 5 MPa. Conclusion: All of the investigated repair materials in combination with the ceramic veneers exhibited Delta E values that were higher than the clinically acceptable limits. Thermal aging negatively affected the SBS values in all groups (P <= .05). All tested self-adhesive composite resins, with the exception of Vertise Flow, could be used instead of a repair kit with flowable composite resin, especially in noncooperative patients, for the purpose of repairing chipping fractures for VITA VM 9, VITA VM 13, and VITA VMK 95 (P > .05).
Shear bond strengths of aged and non-aged CAD/CAM materials after different surface treatments
(Korean Acad Prosthodontics, 2020) Kılınç, Hamiyet; Şanal, Fatma Ayşe; Turgut, Sedanur
PURPOSE. To assess shear bond strengths (SBS) of resin composites on aged and non-aged prosthetic materials with various surface treatments. MATERIALS AND METHODS. Cerasmart (CE), Vita Enamic (VF.), Vita Mark II (VM), and IPS e.max CAD (EC) blocks were sliced, and rectangular-shaped specimens (14 x 12 x 1.5 mm; N = 352) were obtained. Half of the specimens were aged (5000 thermal cycles) for each material. Non-aged and aged specimens were divided into 4 groups according to the surface treatments (control, air abrasion, etching, and laser irradiation; n = 11) and processed for scanning electron microscopy (SEM). The repair procedure was performed after the surface treatments. SBS values and failure types were determined. Obtained data were statistically analyzed (P<.05). RESULTS. The material type, surface treatment type, and their interactions were found significant with regard to SBS (P<.001). Aging also had a significant effect on prosthetic material-resin composite bonding (P<.001). SBS values of non-aged specimens ranged from 12.16 to 17.91 MPa, while SBS values of aged specimens ranged from 9.46 to 15.61 MPa. Non-aged VM in combination with acid etching presented the highest score while the control group of aged CE showed the lowest. CONCLUSION. Etching was more effective in achieving durable SBS for VM and EC. Laser irradiation could be considered as an alternative surface treatment method to air abrasion for all tested materials. Aging had significant effect on SBS values generated between tested materials and resin composite.
Comparison of radiopacity of current restorative CAD/CAM blocks with digital radiography
(Wiley, 2019) Atala, Mustafa Hayati; Atala, Nagehan; Yeğin, Elif; Bayrak, Seval
Objective While the radiopacity of restorative material affects the radiographic diagnosis of the teeth, there is no data about the radiopacity of current restorative computer-aided design (CAD)/computer-aided manufacturing (CAM) materials. Therefore, the present study compared the radiopacity values of current restorative CAD/CAM blocks to facilitate the material choice within such a wide variety of materials. Materials and Methods Specimens were prepared from 13 different restorative CAD/CAM blocks to compare with enamel and dentin. The specimens placed on the occlusal phosphor plate were imaged with aluminum step wedge and tooth section. The radiopacity values were calculated using the Image J program. The radiopacity values of the specimens were converted to mmAl values with the Curve Expert 1.4 program. Results The difference between the radiopacity values of dentin and e.max CAD was not significant, however, they exhibited a significant difference from the other 14 groups (P < .05). Enamel and Obsidien, Suprinity, and Celtra Duo had greater radiopacity values with significant differences from the other 12 materials whereas the difference within these groups was not significant (P > .05). Conclusions The evaluated restorative CAD/CAM materials have significantly different radiopacity values. Among these permanent restoration blocks, the highest radiopacity value was observed in Celtra Duo, the lowest in Block HC.
Effect of UV aging on translucency of currently used esthetic CAD-CAM materials
(Wiley, 2019) Turgut, Sedanur; Kılınç, Hamiyet; Bağış, Bora
Objectives To evaluate the relative translucency parameter (RTP) values of computer-aided design (CAD)-computer-aided manufacturing (CAM) materials after UV aging. Materials and methods 70 specimens (n = 10) of Bruxzir Anterior (BA); E.max Cad (EC); Lava Ultimate (LU); Cerasmart (CE); Vita Enamic (VE); Vita Suprinity (VS); Vita Mark II (VM) were prepared (1 mm +/- 0.01 mm). Color measurements were performed using a spectrofotometer (VITA Easyshade). RTP values of the specimens before (RTP1) and after UV aging (RTP2) were evaluated. Statistical analyses were done with repeated measurements of two-way-ANOVA with Bonferroni test (P < 0.05). Results Evaluating RTP1 and RTP2 values; significant differences were found (P < 0.05). There were no significant difference between the RTP1 values of CE and VS (P = 0.779); EC and VM (P = 0.952); VM and LU (P = 0.995); EP and LU (P = 0.653). Evaluating RTP2 values; VE and BA were found significantly different from the others (P < 0.05). For all evaluated groups TP values decreased after UV aging (P < 0.05). The most RTP reduction was observed for LU; while VM and EC were less affected. Conclusion Glass ceramic VE showed the highest RTP and zirconia-based BA was the most opaque restorative CAD-CAM material. UV aging caused the CAD-CAM materials get more opaque. Clinical significance In cases where translucency is needed chosing VE would give better esthetic results; while zirconia-based BA should be used if more opaque restoration is needed. Clinicians should be aware of that restorations get more opaque after usage.
The effect of microwave glazing on the surface properties of various porcelain materials
(Wolters Kluwer Medknow Publications, 2019) Şanal, Fatma Ayşe; Kurt, Murat
Aim: The aim of this research was to investigate the effect of microwave glazing, conventional oven glazing, and polishing on surface roughness and wettability of porcelains. Materials and Methods: The initial surface roughness values (Ra0) of the prepared specimens for four different porcelains (Vita VM 9, VitaVM 13, Vita VMK 95, IPS e.maxCeram) were determined by profilometry. Then, the specimens were divided randomly into three groups as polishing, conventional oven glazing, and microwave glazing. Final surface roughness values were evaluated by profilometry (Ra1) and scanning electron microscopy. Wettability of glazed specimens were evaluated by contact angle goniometer. Results: Although microwave-glazed specimens had lower Ra1 values compared with the conventional oven-glazed ones for IPS e.maxCeram (P < 0.05), there were not any statistically significant differences between these two procedures in terms of Ra1 values for the other porcelains (P 0.05). Microwave-glazed specimens had lower wettability values than conventional oven-glazed ones for Vita VM 9. Conclusions: Microwave glazing procedure may be considered as an alternative method because of the advantages of providing volumetric heating, time, and energy saving.
Evaluation of reliability of zirconia materials to be used in implant-retained restoration on the atrophic bone of the posterior maxilla: A finite element study
(Korean Acad Prosthodontics, 2019) Değirmenci, Kübra; Büyükdere, Ayşe Koçak; Ekici, Bülent
PURPOSE. Zirconia materials have been used for implant-retained restorations, but the stress distribution of zirconia is not entirely clear. The aim of this study is to evaluate the stress distribution and risky areas caused by the different design of zirconia restorations on the atrophic bone of the posterior maxilla. MATERIALS AND METHODS. An edentulous D4-type bone model was prepared from radiography of an atrophic posterior maxilla. Monolithic zirconia and zirconia-fused porcelain implant-retained restorations were designed as splinted or non-splinted. 300-N occlusal forces were applied obliquely. Stress analyses were performed using a 3D FEA program. RESULTS. According to stress analysis, the bone between the 1) molar implant and the 2) premolar in the non-splinted monolithic zirconia restoration model was stated as the riskiest area. Similarly, the maximum von Mises stress value was detected on the bone of the non-splinted monolithic zirconia models. CONCLUSION. Splinting of implant-retained restorations can be more critical for monolithic zirconia than zirconia fused to porcelain for the longevity of the bone.
Does sterilization affect the push out bond strength of experimental dentin posts?
(Univ Costa Rica, Fac Odontologia, 2019) Tulga, Ayça; Şanal, Fatma Ayşe; Dede, Doğu Ömür
The purpose of this preliminary study is to evaluate the push-out bond strength (PBS) of experimental dentin posts (EDPs) obtained from human and bovine teeth sterilized by autoclaving and gamma radiation. Eighty-four mandibulary premolars were obturated and divided into three post groups: the glass fiber group (Fb) human EDP group (Hm) and the bovine EDP group (Bv). Three subgroups (n=12) were obtained for each EDP groups according to the sterilization methods; no sterilization (Cnt), steam autoclaving (Aut), and gamma radiation (Rad) a total dose of 25 kGy. All posts were cemented to root canals using a dual cured resin cement (Panavia SA). After the micro slices (1 mm in thickness) were obtained of each subgroup, PBS test was performed. Data were analyzed using two-way ANOVA and Tukey's multiple comparison tests (alpha=.05). The post type and sterilization method was significantly effective on the PBS values according to the ANOVA (P<.001). No sterilization apllied EDP groups showed significantly higher PBS values than the sterilized groups (P<.001). Bv_Cnt (9.42 +/- 1.31) showed significantly lower PBS values than both Fb (12.36 +/- 1.54) and Hm_Cnt (11.06 +/- 1.38) groups (P<.001). Both steam autoclaving and gamma radiation affect the PBS values and fracture modes of EDPs negatively. The bovine EDPs are not as effective as human EDPs with regard to the PBS to the root dentin.

Güncel Gönderiler