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Aim: The aim of this study was to evaluate the effect of PEEK abutments, an alternative to titanium abutments, with temporary acrylic restorations using immediate loading protocol on the marginal bone loss and peri-implant tissues. Methodology: This study was performed with temporary restorations using 32 titanium and PEEK abutments (14 titanium and 18 PEEK) on 32 implants performed on 21 patients (13 females, 8 males). Before surgical placement of the implants, intraoral and radiographic examinations were performed. The patients were divided into two groups as titanium abutment group (Grup Ti) and PEEK abutment group (Grup PEEK). In both groups, all implants were placed according to the manufacturer's recommendations. After surgery, impressions were taken using polyvinyl siloxane impression material and closed tray impression technique. The gingiva, which is thought to be formed on the model, was scraped and screwed onto the appropriate titanium or PEEK abutment analogue according to the groups and temporary restoration was prepared and applied on the implant. Results: The results of the statistical analysis show that abutment types have no significant effect on ISQ values (p>0.05), but the diameter of the implant significantly affected ISQ values independently from abutment type (p0.05). Conclusion: Within the limitations of this study, there was less bone loss in the PEEK abutment group (p0.05). How to cite this article: Gül İ, Zortuk M, Öztürk C. Effects of abutment materials on the tissues surrounding dental implants immediately after loading: An in vivo study­. Int Dent Res 2021;11(Suppl.1):1-6. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.1 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Background/Aim: The aim of this study was to evaluate the bond strength of glass ceramic inlay system using 2 antibacterial adhesive luting protocols with 2 cementation techniques to bur-cut dentin. Material and Methods: Class I inlay cavities with 6-degree occlusal divergence and size of 6-, 3and 2-mm in length, width and depth, were prepared on extracted human molars, randomly assigned to 2 main groups; each to 1 cementation technique, with or without immediate-dentin-bonding (IDB or NIDB) further divided into 3 subgroups; 2 to 2 antibacterial luting protocols, traditional (T) and experimental (E); and 1 to a control (C) group. In group IDBT, IDB-E and IDB-C dentin bonding was applied immediately after cavity preparation. In group NIDB-T, NIDB-E and NIDB-C dentin bonding was applied just before cementation of the restorations. The cavities in IDB-T and NIDB-T were treated with 2% chlorhexidine-digluconate (CHX) prior to dentin bonding application. The cavities in IDB-E and NIDB-E were treated only with dentin bonding system containing MDPB (12-methacryloyloxydodecylpyridinium bromide) active monomer featuring antibacterial effect. IDB-C and NIDB-C served as control. Dual-cure adhesive resin cement was used for the cementation of Lithium disilicatebased ceramic inlay restorations. Fourteen test specimens per group were prepared for microtensile testing and consecutively subjected to tensile load at a crosshead speed of 1 mm/min. The mode of failure was observed under SEM and evaluated for each group. The Kruskal-Wallis test was used to investigate the statistical difference between groups (a=0.05). Results: The microtensile load was 5.96 MPa (median: 5.99 MPa) for IDB-T, 7.23 MPa (median: 7.55 MPa) for IDB-E, 6.68 MPa (median: 6.56 MPa) for IDB-C, 7.24 MPa (median: 7.20 MPa) for NIDB-T, 6.98 MPa (median: 6.30 MPa) for NIDB-E, and 7.02 MPa (median: 6.99 MPa) for NIDB-C, with no statistical difference between the groups (p>0.05). SEM monitoring for mode of failure revealed either cohesive (within resin cement) or adhesivecohesive (mostly within resin cement along with partially involved areas between resin cement and ceramic restoration) character. Conclusions: Within the limitations of the current study, none of the tested antibacterial luting protocols with either cementation technique was found to be superior in terms of bond strength.

Amaç: Yumuşak astar maddeleri; atrofik bölgelerde oluşan kuvvet dağılımlarını azaltmak amacıyla, protezlerin doku yüzeylerine uygulanan polimerlerdir ve bir çoğunun sıvı absorbsiyon ve adsorbsiyonu eğilimlerinden dolayı zaman içerisinde renklenmeleri söz konusudur. Bu çalışmanın amacı kahve ve çay solüsyonlarında yapay olarak renklendirilmiş 3 farklı yumuşak astar materyalinin renk parametreleri üzerinde protez temizleyicilerinin etkinliğinin değerlendirilmesidir.Gereç ve Yöntemler: Üç farklı yumuşak astar maddesi kullanılarak, her grupta 20 tane olmak üzere toplam 60 adet 8 mm çapında 2 mm kalınlığında dairesel örnekler hazırlandı. Her gruptaki örnekler kullanılacak yaşlandırma solüsyonuna göre (çay ve kahve) iki alt gruba ayrılarak (n:10) yapay yaşlandırma işlemi 48 saat süresince uygulandı. Örneklerin CIE L*, a* ve b* değerleri, başlangıç, yaşlandırma ve temizleme işlemlerinden sonra spektrofotometre cihazı kullanılarak her örnekten 3’er ölçüm yapılarak ölçüldü. Örneklerde meydana gelen renk değişimi ise ΔE00 formülü kullanılarak hesaplandı. Elde edilen veriler tekrarlanan ölçümler Anova ve Tukey HSD post – hoc testi kullanılarak 0,05 anlamlılık düzeyinde değerlendirildi.Bulgular: Yapılan istatistiksel analiz sonuçlarına göre, yaşlandırma ve temizleme işlemlerinin yumuşak astar maddelerinin renk parametreleri üzerine anlamlı bir etkisi olduğu tespit edilmiştir (p, Amaç: Yumuşak astar maddeleri; atrofik bölgelerde oluşan kuvvet dağılımlarını azaltmak amacıyla, protezlerin doku yüzeylerine uygulanan polimerlerdir ve bir çoğunun sıvı absorbsiyon ve adsorbsiyonu eğilimlerinden dolayı zaman içerisinde renklenmeleri söz konusudur. Bu çalışmanın amacı kahve ve çay solüsyonlarında yapay olarak renklendirilmiş 3 farklı yumuşak astar materyalinin renk parametreleri üzerinde protez temizleyicilerinin etkinliğinin değerlendirilmesidir.Gereç ve Yöntemler: Üç farklı yumuşak astar maddesi kullanılarak, her grupta 20 tane olmak üzere toplam 60 adet 8 mm çapında 2 mm kalınlığında dairesel örnekler hazırlandı. Her gruptaki örnekler kullanılacak yaşlandırma solüsyonuna göre (çay ve kahve) iki alt gruba ayrılarak (n:10) yapay yaşlandırma işlemi 48 saat süresince uygulandı. Daha sonra örnekler distile su ile yıkanarak protez temizleme tabletiyle hazırlanan solüsyonda 24 saat bekletildi. Örneklerin CIE L*, a* ve b* değerleri, başlangıç, yaşlandırma ve temizleme işlemlerinden sonra spektrofotometre cihazı kullanılarak her örnekten 3’er ölçüm yapılarak ölçüldü. Örneklerde meydana gelen renk değişimi ise ΔE00 formülü kullanılarak hesaplandı. Elde edilen veriler tekrarlanan ölçümler Anova ve Tukey HSD post- hoc testi kullanılarak 0,05 anlamlılık düzeyinde değerlendirildi.Bulgular: Yapılan istatistiksel analiz sonuçlarına göre, yaşlandırma ve temizleme işlemlerinin yumuşak astar maddelerinin renk parametreleri üzerine anlamlı bir etkisi olduğu tespit edilmiştir (p

Objectives: The purpose of this study was to compare the retention strength of implant-supported crowns produced by traditional lost-wax, direct metal laser sintering, CAD/CAM technique by using three different luting cements. Materials and Methods: Ninety standard titanium abutments screwed to analogs then mounted in acrylic resin. Samples divided into three main groups according to the manufacturing technique (N=30). Then groups divided into three subgroups based on the cement type used (n=10). The specimens subjected to the pull-out test by using an universal testing machine at a 1 mm/min crosshead speed. The highest pull-out strength values were recorded in Newton and statistical analyzes were performed by using Two-way ANOVA test and multiple comparison test with Bonferroni correction at a significance level of 0.05.Results: The two-way analysis of variance revealed that the fabrication technique and cement type had a significant effect on pull-out strength (p0.05). The highest pull-out strength was found in the laser sintering group, while the conventional technique had the lowest values. Within the subgroups self-adhesive resin cement had the highest pull-out strength, traditional cement subgroup had the lowest. Conclusions: Fabrication technique and cement type have statistically significant effect on the retention of the implant-supported crowns.

İmplant üstü restorasyonlar simante ve vidalı olarak tasarlanabilmektedir. Sonlu elemanlar analizi yöntemi (SEA) ile simante ve vidalı implant üstü restorasyonlarda periimplant bölgedeki kortikal ve spogiöz kemikte, implant ve abutmentlarda oluşan stres dağılımını incelemektir. Gereç ve Yöntemler: Bilgisayar destekli tasarım yazılımı kullanılarak, tek üye seramik restorasyonlu iki çalışma modeli tasarlandı. Üç boyutlu kemik içerisine implant yerleştirildi, simante ve vidalı olmak üzere iki farklı abutment tasarımı yapıldı. İmplantın çevresinde en az 1 mm trabeküler kemik olacak şekilde ve çene kemiğinin etrafında kortikal kemik kalınlığı 2 mm olacak şekilde modellendi. Abutment yükselikleri simante tasarımda 4 mm ve vidalı tasarımda ise 1 mm olarak modellendi. İmplant ve abutmentlar vida aracılığıyla birbirine bağlandı. Abutmentlar üzerine mandibuler birinci büyük azı diş monolitik zirkonya kron tasarımı basit bir şekilde modellendi ve 300 N’luk oklüzal kuvvetin uygulanacağı distal üçgensel fossaya denk gelen bölgesi her iki kron tipinde de aynı bölgede olacak şekilde belirlendi. Tüm modeller ağ oluşturma ve stres analizi için SEA yazılımına aktarıldı. Bulgular: Maksimum asal gerilme değerlerinin vidalı sistemlerde büyük (34,7 MPa), minimum asal gerilme değerlerinin ise simante sistemlerde büyük olduğu görülmüştür (104,7 MPa). Sonuç: SEA sınırları dâhilinde, vidalı sistemlerin abutment ve vida üzerinde oluşturduğu stres değerleri daha fazladır, Objective: Implant supported restorations can be designed as cemented or screw retained. The purpose of this study was to evaluate the stress distribution of implant supported cemented and screw retained restorations using finite element methods. Material and Methods: Two working models with ceramic restoration were designed using a computer aided design software. Two different abutment designs were made as cemented and screw retained. The design was modelled to have at least 1 mm of trabecular bone around the implant and a cortical bone thickness of 2 mm around the jawbone. The abutment heights are modeled as 4 mm for the cemented and 1 mm for the screw retained. Implants and abutments were connected to each other with screw. The mandibular first molar crown designs on the abutments were modeled and the occlusal force was applied to the same region in both crown types corresponding to the distal triangular fossa. All models were transferred to FEM software for networking and stress analysis. Results: The maximum principal stress values were found to be higher (34.7 MPa) in screw retained systems and the minimum principal stress values were higher in cemented systems (104.7 MPa). Conclusion: Within the limitation of this study, screw retained design showed higher stresses concentration on the implant abutment and screw.

To determine the effects of two different sterilization methods on the pull-out bond strength, flexural strength, and elastic modulus of glass-fiber posts.A total of 69 glass-fiber posts were used. The posts were divided into three groups according to applied sterilization method: 1) control, 2) ethylene oxide gas (EOG), and 3) autoclave. The microstructure of three posts from each group was evaluated by SEM and energy-dispersive X-ray spectroscopy (EDS). Thirty glass-fiber posts were used to evaluate pull-out bond strength. The three-point bending test was performed to analyze the flexural strength on another 30 glass-fiber posts. Failure modes were categorized microscopically after the pull-out test. After the three-point bending test, micromorphology at the bending area was examined using SEM.One-way ANOVA indicated no statistically significant differences among the group means in terms of bond strength (p0.05), flexural strength (p0.05), or elastic modulus (p0.05). EDS revealed that the weight percentage of surface oxygen atoms in the EOG- and autoclave-sterilization groups were significantly higher. SEM images were similar.The results of this study show that glass-fiber posts can be sterilized either by autoclave or EOG when necessary, without any negative effect on bond strength, flexural strength, or elastic modulus.

Objective: The aim of this pilot study was to compare the effects of pretreatments on leakage of zirconia ceramics. Materials and Methods: The speciments divided into 6 groups that were subsequently treated as follows: group 1, no treatment (control); group 2, the ceramic surfaces were airborne-particle abraded with 110 μm aluminum-oxide (Al2O3) particles; group 3, after abrasion of the surfaces with 110 μm Al2O3 particles, silica coating using 30 μm (Al2O3) particles modified by silica (rocatec system) and application of the silane coupling agent (espe-sil); group 4, ceramic surfaces irritated with neodymium-doped yttrium aluminium garnet (Nd:YAG) laser [fidelis plus 3 foton (Ljubljana, Slovenia)] at 20 hz, 100 mj, 2 w, 100 μs; group 5, ceramic surfaces irritated with Nd:YAG laser at fidelis plus 3 fotona (Ljubljana, Slovenia) at 20 hz, 100 mj, 2 w, 100 μs; group 6; application of a zirconia primer (z-prime plus bisco, IL, USA) agent. And all ceramics tested for leakage. Results: For marginal leakage, score 0 was found in all groups. Conclusion: No significant differences were found in marginal leakage under all conditions.

Background This study is to compare the two different techniques used in the labeling of implant-based fixed prostheses, using the square code and using microchip labeling techniques, taking into account the properties of an ideal prosthetic labeling technique. Sixty implants fixed prostheses were produced, 30 for each group. Square codes were created on the lingual bands of implants fixed prostheses which are the samples of the group that were labelled by using square code, and microchips were placed in the implant abutments of the samples in the group that were labelled with the microchip. Results The thermal cycle test was used to compare the long-life cycle of the samples, and no deformation was found. A survey attended by 51 dentists was created to evaluate the techniques’ effects on their aesthetic appeal and their application. The data found was statistically evaluated, and the result was statistically insignificant (p

Background/purpose: The aim of this study was to determine the accuracy of casts made from irreversible hydrocolloid impressions with immediate and delayed pouring. Materials and methods: A master model was mounted on a modified articulator designed to standardize impression procedures. A total of 250 impressions were taken and grouped into 25 groups (n = 10) according to irreversible hydrocolloid material (CA37, Tropicalgin, ColorChange, Hydrogum 5, and Hydrocolor 5) and storage time (0 hours, 1 hour, 24 hours, 72 hours, and 120 hours). Impressions were stored at 23 ± 1°C and 100% relative humidity and poured with gypsum at the predetermined storage time. Casts were scanned with a three-dimensional (3D) model scanner. The digital models were measured and subtracted from the measurements obtained from the master model. The absolute values of dimensional differences were statistically analyzed using two-way analysis of variance (ANOVA) and post hoc Fisher LSD test (P 0.05). However, after 72 hours and 120 hours of storage, Tropicalgin and CA37 irreversible hydrocolloid impressions were found to be significantly different (P 0.05). Conclusion: All of the conventional and extended-pour impression materials tested in this study can be poured up to 24 hours with accuracy, if impressions are correctly stored. Extended-pour impression materials (ColorChange, Hydrogum 5, and Hydrocolor 5) can be poured up to 120 hours, if stored correctly.

PURPOSE This study compared the clinical outcomes of 1-year follow-up of immediate and late implant loading after implant restoration of a single tooth in the anterior maxilla. MATERIALS AND METHODS Thirty-three patients with missing teeth in the anterior maxilla were included in this study (18 immediate loading and 15 late loading). Standard periapical radiographs were obtained to evaluate the vertical bone loss around the implant. For both implant groups, periimplant parameters (probing depth, gingival bleeding index, gingival index (GI), modified plaque index, width of keratinized gingiva) were evaluated. RESULTS There were no significant differences in bone loss, the widths of keratinized gingiva, the GI, and modified plaque index between the immediate implant loading and late implant loading groups (P > 0.05). A significant difference in the probing depth was observed between these groups at the initial and 1-month evaluations (P < 0.05). Significant differences in bleeding indices between these groups were observed at months 3 and 6 (P < 0.05). CONCLUSIONS When selecting appropriate patients (adequate primary stability, patient compliance with the surgeon's recommendations), immediate implant loading may be an alternative method to late loading protocol for replacement of a missing tooth in anterior maxilla.

Objectives: The aim of the present study was to evaluate the cytotoxic effects of three different provisional restoration materials on fibroblasts. Two bis-acrylic based [Tempofit Duomix (Detax), Protemp 3 Garant (3M ESPE)] and one urethan dimethacrylate [Revotek LC (GC Corporation)] based provisional restoration materials used.Methods: Materials were prepared according to the manufacturers’ instructions in standard teflon disks (2×5mm) and four samples were extracted in 7 ml of Basal Medium Eagle with 10% new born calf serum and 100 mg/ml penicillin/streptomycin for 24 hours. The L929 fibroblast cells were plate (25.000 cells/ml) in well plates, and maintained in a CO2 incubator at 37°C for 24h. After 24 hours, the incubation medium was replaced by the immersed medium in which the samples were stored and the L929 fibroblasts were incubated in contact with eluates for 24 hours at 37°C for 24h. The fibroblast cell viability was analyzed by measuring the mitochondrial activity with the methyltetrazolium test (MTT). Twelve well used for each specimen and experiment repeated for two times. The data was statistically analyzed by Mann-Whitney U tests.Results: The results showed that, Revotek LC and Protemp 3 Garant were not cytotoxic for fibroblast cells when compared to control group (P>.05). However, Tempofit duomix was cytotoxic for L929 fibroblasts when compared to control group and other tested materials (P%.05).Conclusions: Taking into consideration the limitations of an in vitro study, our study indicate that provisional restoration materials might have cytotoxic effects on fibroblasts and should be selected carefully for clinical applications. (Eur J Dent 2009;3:114-119)

Introduction: Screw loosening is one of the most common mechanical complications within the prosthetic components of dental implants. Clinicians must know if reverse torque values (RTVs) are affected by contamination of the implant abutment screw hole with either blood, saliva or chlorhexidine. Methods: Forty implants were divided into 4 groups (n = 10). Implants were embedded in epoxy resin and placed in a digital torque meter. Screw holes of 30 implants were contaminated with either chlorhexidine (CG), fresh human saliva (SG), or blood (BG), and the remaining noncontaminated screws served as a control group (NC). Abutment screws were tightened using a hand-held torque meter (25 N·cm). Thermocycling (1500 cycles) was performed, and abutment detorque values were calculated using the digital torque meter. Results: RTVs were lower than insertion torque values for all groups. According to Tukey HSD Test, blood contamination of abutment screws resulted in significantly lower RTVs (18.950 ± 2.641 N·cm) when compared with controls. Conclusions: Blood contamination of abutment screw holes was shown to significantly decrease RTVs. Blood contamination may result in greater loosening of implant screws in clinical practice. Copyright © 2014 by Lippincott Williams & Wilkins.

The widespread use of endosseous osseointegrated implants to replace missing natural teeth increases the chances of implant complications and failures, despite the high initial success rate reported in the literature. Implant and healing cap fracture are possible rare complications that can cause significant problems for both clinicians and patients. This article reports on 2 unique cases of implant and healing cap fracture, their possible causes, and how the cases were managed.

Aim This study aimed to compare the fracture resistance of roots filled with a bonded material, fiber posts, or titanium post systems. Methods Canals in the first group were filled with AH Plus and gutta-percha cones, and roots in the second group were filled with Epiphany sealer and Resilon cones. The root fillings (60 roots) were removed up to 4 mm from the canal apex to obtain 10-mm-deep post spaces, and posts were cemented. The groups were as follows: AH Plus control group, Epiphany control group, AH Plus fiber post group, AH Plus titanium post group, Epiphany fiber post group, and Epiphany titanium post group. Fracture tests were performed by using an Instron testing machine. The force was applied at a 45° axial angle with a constant speed of 1 mm/min. For each sample, the force at which fracture occurred was recorded in units of newtons. Statistical analysis was carried out by using analysis of variance test. Results There was no statistically significant difference between all groups ( P > .05). Conclusions Titanium posts, fiber posts, and Epiphany root canal filling systems were found to have no reinforcing effect on endodontically treated roots.

In this study, we have explored the prospect of assessing and following level of total denture adaptation by use of EMG signals recorded during gum chewing. Total of 14 edentulous patients, 6 women and 8 men, with an average age of 63 +/- 9 years, were recruited. Separate EMG recordings were obtained from left and right temporalis and masseter muscles of the patients for a period of 10 seconds, while they were chewing a sugar-free gum on their left and right sides. EMG recordings were repeated at three times: before, right after, and six months after the placement of the denture. We have tried to standardize environmental and individual factors during EMG recordings. The EMG data have been pre-processed and analyzed using Discrete Wavelet Transform (DWT) and obtained features were statistically evaluated using the paired sample t-test. Chewing activity on the right and left side is analyzed by making comparisons of muscle activity between before and right-after cases and before and six-months-after denture fixation cases. A comparison between right and left side mastication is also made at different time points. We have suggested and implemented a new test and comparison procedure in order to assess adaptation to denture fixation using EMG analysis. In this study, the results indicate that DWT based EMG analysis is instrumental in evaluating denture adaptation and as time progresses the adaptation to denture and hence chewing efficiency increases in patients with total denture replacement., In this study, we have explored the prospect of assessing and following level of total denture adaptation by use of EMG signals recorded during gum chewing. Total of 14 edentulous patients, 6 women and 8 men, with an average age of 63±9 years, were recruited. Separate EMG recordings were obtained from left and right temporalis and masseter muscles of the patients for a period of 10 seconds, while they were chewing a sugar-free gum on their left and right sides. EMG recordings were repeated at three times: before, right after, and six months after the placement of the denture. We have tried to standardize environmental and individual factors during EMG recordings. The EMG data have been pre-processed and analyzed using Discrete Wavelet Transform (DWT) and obtained features were statistically evaluated using the paired sample t-test. Chewing activity on the right and left side is analyzed by making comparisons of muscle activity between before and right-after cases and before and six-months-after denture fixation cases. A comparison between right and left side mastication is also made at different time points. We have suggested and implemented a new test and comparison procedure in order to assess adaptation to denture fixation using EMG analysis. In this study, the results indicate that DWT based EMG analysis is instrumental in evaluating denture adaptation and as time progresses the adaptation to denture and hence chewing efficiency increases in patients with total denture replacement.

Purpose: To investigate the effects of fatiguing test on the fracture strength of all-ceramic crowns (IPS Empress II, Conventional InCeram and Celay InCeram). Material and Methods: Twenty crown; shapes 8mm in diameter and 7mm in height were fabricated for each all-ceramic system. For each ceramic system, 10 specimens were tested for fracture strength without fatiguing. A secondly, remaining specimens was submitted to a fatiguing and then fractured using a universal testing machine for each systems. The results were statically analyzed using a one way ANOVA and Student t test. Results: When comparing the fracture strength of all-ceramic crowns with and without the fatiguing test, the strength was lower after fatiguing (p, Amaç: Yorulma testinin tam seramiklerin (IPS Empress II, Geleneksel InCeram ve Celay InCeram) k r lma direnci üzerine etkisinin ara t r lmas .Gereç ve Yöntem: Her seramik sistemi için 8 mm çap nda 7 mm yüksekli'inde 20 adet master die haz rland . Her seramik sistemi için 10 adet örne'in k r lma direnci yorulma testi uygulanmadan test edildi. .kinci olarak, her gruba ait kalan örneklere yorulma testi uyguland ve universal test cihaz kullan larak k r lma testi yap ld . Elde edilen sonuçlar tek yönlü ANOVA ve student t testi kullan larak de'erlendirildi. Bulgular: Yorulma testi uygulanan ve uygulanmayan tam seramik kronlar kar la t r ld ' zaman, yorulma testi sonras bütün gruplarda k r lma direnci de'erleri azald (p

The effects of desensitizer, disinfectant, saliva, blood, and hydrogen peroxide on the tensile bond strength between adhesive and ceramic as well as between adhesive and dentin were examined. Sixty 7x3 mm pressed ceramic discs of IPS e.max were fabricated and randomly assigned to six groups of different dentin surface treatments (control, desensitizer, disinfectant, saliva, blood, and hydrogen peroxide). Representative samples of fractured specimens were observed by SEM (scanning electron microscopy). There were significant differences between the control group and saliva, blood, and hydrogen peroxide groups (p0.05). Results of this study suggested that only saliva, blood, and hydrogen peroxide influenced the tensile bond strength between dentin and ceramic.

Purpose: This study investigated the effects of different desensitizers and an adhesive material application on pulpal temperature rise during direct provisional restoration polymerization. Materials and Methods: Two dentin desensitizers (Systemp, Ivoclar; BisBlock, Bisco) and a dentin adhesive (Prime Bond, Dentsply) were applied to the dentin surfaces as single layer or double layer. One autopolymerizing methacrylate (Prevision, Heraeus Kulzer) and one light polymerizing composite (Revotek LC, GC) provisional restoration materials were used in this study. A total of 160 dentin disks were prepared from extracted molars. These dentin disks were placed on an apparatus developed to measure temperature rise. After the desensitizer or dentin adhesive application, provisional materials were polymerized according to the manufacturers' instructions. The temperature increase was measured under the dentin disk with a J-type thermocouple wire that was connected to a data logger. Differences between initial and highest temperature reading were taken, and 10 readings were averaged to determine the mean value in temperature rise. Statistical analysis was performed with three-way analysis of variance followed by Tukey HSD test (α = 0.05). Results: Temperature rise varied according to the provisional restoration material used (composite resin, methacrylate) (p < 0.001), the agent thickness (single, double) (p < 0.001), and the agent (desensitizer, adhesive) (p < 0.001). The composite resin-based provisional material induced higher thermal changes than methacrylate based provisional material (p < 0.01). Conclusion: The thickness of desensitizing agents affected the thermal changes; however, the desensitizers did not affect on the intrapulpal temperature although the type of provisional material used may be effective. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2009

Objectives: The aim of this study was to investigate surface roughness in provisional crown acrylics, after polishing, reinforced with different concentrations of glass fibers.Methods: A total of 48 disk-shaped specimens were prepared using autopolymerizing acrylic resin. These specimens were divided into four groups according to the level of glass fiber added: Group A (no fiber), Group B (0.5%), Group C (1%) and Group D (2%). After polishing the specimens, an average surface roughness (Ra) value was calculated using a profilometer from four randomly selected points on the surface.Results: A significant difference was determined among the surface roughness values of provisional crown resins to which different concentrations of fiber had been added (PConclusions: The reinforcement of provisional crown and fixed partial denture resin with glass fibers increases surface roughness. (Eur J Dent 2008;2:185-190)

BACKGROUND In recent years, glass fibres have been used to strengthen denture base resins. A major difficulty in using reinforcing fibres with multiphase acrylic resins, such as powder liquid resins, is inadequate impregnation of the fibres with the resin. METHODS This investigation examined the reinforcing effect of glass fibres on the fracture resistance and flexural strength of acrylic denture base resins. Eighty identical specimens were formed in specially designed moulds in accordance with the manufacturer's recommendations. The four experimental groups were prepared and these consisted of conventional acrylic resin and the same resin reinforced with glass fibres. Ten specimens were fabricated in a standardized fashion for each experimental group. Flexural strength was tested using a 3-point universal testing machine. RESULTS In this study, statistically significant differences were found in the flexural strength of the specimens (P < 0.05). The injection-moulded, fibre-reinforced group had significantly lower flexural strength than the injection-moulded group (P < 0.001), strength than the microwave-moulded, fibre-reinforced group (P < 0.001), and the microwave-moulded, fibre-reinforced group had lower flexural strength than the microwave-moulded group. The fracture resistance was significantly higher in the injection-moulded, fibre-reinforced group than in the injection-moulded group (P < 0.05), and the fracture resistance was significantly higher in the microwave-moulded, fibre-reinforced group than in the microwave-moulded group. CONCLUSION Within the limitations of this study, the flexural strength of heat-polymerized PMMA denture resin was improved after reinforcement with glass fibres. It may be possible to apply these results to distal extension partial and complete denture bases.

Labelled dentures can be important in identifying people who have lost their memory or in identifying the bodies of those who have died in disasters. Forensic dentistry has long considered marking dentures, although no standardised method has been developed. Of the many options considered, none maintain the marking after the dentures break or are altered in occurrences such as plane crashes, which can result in a marked increase in temperature. This study examined a ceramic marking system that can endure high temperatures and can also be used in fixed partial dentures.

PURPOSE. The purpose of this study was to evaluate the effect of provisional cement removal by different dentin cleaning protocols (dental explorer, pumice, cleaning bur, Er:YAG laser) on the shear bond strength between ceramic and dentin. MATERIALS AND METHODS. In total, 36 caries-free unrestored human third molars were selected as tooth specimens. Provisional restorations were fabricated and cemented with eugenol-free provisional cement. Then, disc-shaped ceramic specimens were fabricated and randomly assigned to four groups of dentin cleaning protocols (n = 9). Group 1 (control): Provisional cements were mechanically removed with a dental explorer. Group 2: The dentin surfaces were treated with a cleaning brush with pumice Group 3: The dentin surfaces were treated with a cleaning bur. Group 4: The provisional cements were removed by an Er:YAG laser. Self-adhesive luting cement was used to bond ceramic discs to dentin surfaces. Shear bond strength (SBS) was measured using a universal testing machine at a 0.05 mm/min crosshead speed. The data were analyzed using a Kolmogorov Smirnov, One-way ANOVA and Tukey HSD tests to perform multiple comparisons (alpha=0.05). RESULTS. The dentin cleaning methods did not significantly affect the SBS of ceramic discs to dentin as follows: dental explorer, pumice, cleaning bur, and Er:YAG laser. CONCLUSION. The use of different cleaning protocols did not affect the SBS between dentin and ceramic surfaces. [J Adv Prosthodont 2012;4:192-6]