This study compared two groups of patients who were elderly and edentulous, one group included subjects who had mandibular overdentures supported by two implants (Group I); the other groups wore conventional complete dentures (Group II). This retrospective study included 100 edentulous patients (50 from each group) with an average age of 67.86 years, who had been followed for 4 years. The groups were compared in terms of patient satisfaction, quality of life (QOL), and bite force. The bite force and patient satisfaction scores of Group I were found to be statistically significantly higher than Group II (p < .05). However, no statistically significant difference was found between the two groups' QOL scores (p > .05) except on the physical pain subscale (p = .013). Based on these results, it can be concluded that after 4 years of function, subjects wearing mandibular overdentures supported by two implants had higher values for bite force and patient satisfaction scores, but similar QOL scores when compared to conventional complete denture-wearers.
Objective
The aim of this study was to evaluate the color stability of a heat polymerized resin, an auto-polymerizing resin, a urethane dimethacrylate resin and a CAD/CAM PMMA block resin stored in different storage media.
Materials and methods
60 disc-shaped specimens (15×2 mm) were fabricated for each group. A total of 240 disc-shaped specimens were thermal-cycled for 5,000 cycles. Then specimens were randomized into 4 groups (n= 15) according to storage media: coffee, coke, red wine and distilled water (control group). The color measurement of each sample was performed using a spectrophotometer before and after storage (after 7 and 30 days), and color changes (ΔE) were calculated.
Results
All the denture base materials demonstrated dissimilar color changes after stored in the different storage media in both evaluation stages. In all storage media, CAD-CAM denture base resins showed the minimum in color change. In all denture base resins, red wine showed a higher degree of color change than coke or coffee.
Conclusion
The color stability of CAD-CAM denture base resins is better than any of the other kind of denture base resins. The color change values of all groups except Eclypse stored in red wine had clinically detectable values.
Within the limitations, it can be concluded that although clinical studies are needed to ensure the findings of the present study, due to severe retention loss and volumetric abutment wear, ball attachments with titanium female components should be used with caution.
The establishment of stability of a dental implant is mandatory for successful osseointegration. Resonance frequency analysis (RFA) is the most frequently used method for the clinical measurement of implant stability. The purpose of the present study was to evaluate the reliability of the recently developed RF analyzer named as Penguin RFA and to compare it with the traditional RF analyzer Osstell ISQ. Sixty implants were inserted into fresh vertebrae and pelvis belonging to a steer. Implant stability was measured using Penguin RFA by its transducers (multipegs) and Osstell ISQ by its transducers (smartpegs). Additionally, stability was measured by multipegs with Osstell ISQ and by smartpegs with Penguin RFA. The intra-observer and inter-observer reliability of Penguin RFA were estimated by the intra-class coefficient (ICC). Mean implant stability quotients (ISQs) measured with Osstell ISQ were higher than the ISQs measured with Penguin RFA (P<.05). The intra- and inter-observer reliability of Penguin RFA were considered as excellent (ICC > 0.7). For Osstell ISQ, no significance in ISQs was detected between the readings by smartpegs and multipegs (P > .05) while for Penguin RFA ISQs by smartpegs were significantly higher than the ISQs by multipegs (P <.05). Recently developed Penguin RFA, is reliable and can be used in the clinical practice for the measurement of dental implant stability in regardless of the bone type. The multipegs originally manufactured for the Penguin RFA is also compatible with Osstell ISQ.
The present study evaluated the bond strengths of prefabricated PolyEtherKetoneKetone (PEKK) posts, PEKK posts custom‐configured according to root‐canal size, and conventional fiber posts. A total of 30 maxillary incisors were randomly divided into three groups, as follows: Group 1: fiber posts; Group 2: prefabricated PEKK posts; Group 3; custom‐made PEKK posts. Following endodontic treatment, post spaces were prepared, and posts were cemented with resin cement. Push‐out bond strength testing was performed using a universal testing machine, and fractures modes were examined under a scanning electron microscope. Data were analyzed using One‐way ANOVA and Tukey's HSD tests, with the level of significance set at .05. The highest bond‐strength values in the cervical section were observed with the custom‐made PEKK post (17.3470 MPa), whereas the highest bond‐strength values in the middle and apical sections were observed with the conventional fiber posts (11.5375 MPa and 6.8625 MPa, respectively). Bond‐strength values for all posts systems decreased in a cervical to apical direction. PEKK posts are a suitable alternative to fiber posts. Although custom‐made PEKK posts demonstrated better bond strength than prefabricated PEKK posts, further studies are needed to evaluate their clinical performance.
The aim of the present study is to evaluate the wear resistance and microhardness of various interim fixed prosthesis materials with different chemical compositions and curing methods. One heat-cured and four self-cured acrylic resins, and three self-cured, one light-cured, and one dual-cured composite-based materials were tested. For microhardness, samples from each group were tested after storing either at 37°C in artificial saliva for 7 days, followed by thermocycling, or in distilled water solution at 37°C for 24 h. For the evaluation of wear, the remaining samples were evaluated using a 3D scanner and a surface analysis program before loading in the chewing simulator and after every 10,000 cycles. There was a significant difference in wear behavior among the materials tested at both 10,000 and 20,000 cycles (P < 0.001). Microhardness and wear resistance were significantly different between acrylic and composite materials.
This in vitro study evaluated the microhardness and two-body wear of various computer-assisted design and computer-assisted manufacturing (CAD/CAM) resin-matrix ceramic materials stored in different storage media. For each material (Paradigm MZ100, Lava Ultimate, Vita Enamic, and Cerasmart), 40 disk-shaped specimens
The design of an implant has a great effect on primary stability. The purpose of this study was to determine the differences in primary stability between straight and tapered Neoss ProActive implants in type I and type III bones using resonance frequency analysis (RFA) and electronic percussive testing (EPT) methods. Fresh cow vertebrae and pelvis were used as models of type III and type i bone, respectively. Implants of 2 different designs—straight and tapered Neoss ProActive implants with a thread cutting and forming (TCF) design, both 3.5-mm wide and 11-mm long—were placed in both types of bone (n = 60). The primary stability of all implants was measured by an experienced clinician blinded to the study protocol using the EPT and RFA devices. No statistically significant difference was found between the implant stability quotients and the percussive test values of straight and tapered implants in either bone type. Within the limitations of this ex vivo study, it may be concluded that the shape of an implant with a TCF design does not affect primary stability.
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