This study aimed to describe different staining protocols for the main dental ceramics. A bibliographic search was conducted in the main health databases PubMed and Scholar Google, in which 100 studies published were collected. In vitro and in silico studies, case reports, and systematic and literature reviews, on ceramic materials, were included. Therefore, articles that did not deal with the topic addressed were excluded. Ceramics can be classified into glass-matrix ceramics (etchable), polycrystalline (non-etchable), and hybrid ceramics. In this context, different fabrication methods, method indications, and characterization layers can be used for each ceramic group and numerous protocols differ according to the choice of material. Several ceramic systems are available, thus professionals in the prosthetic area need constant updates on dental ceramic restorations and their proper characterizations.

This study aimed to evaluate the use of bioengineering tools, finite element analysis, strain gauge analysis, photoelastic analysis, and digital image correlation, in computational studies with greater validity and reproducibility. A bibliographic search was performed in the main health databases PUBMED and Scholar Google, in which different studies, among them, laboratory studies, case reports, systematic reviews, and literature reviews, which were developed in living individuals, were included. Therefore, articles that did not deal with the use of finite element analysis, strain gauge analysis, photoelastic analysis, and digital image correlation were excluded, as well as their use in computational studies with greater validity and reproducibility. According to the methodological analysis, it is observed that the average publication of articles in the Pubmed database was 2.03 and with a standard deviation of 1.89. While in Google Scholar, the average was 0.78 and the standard deviation was 0.90. Thus, it is possible to verify that there was a significant variation in the number of articles in the two databases. Modern dentistry finds in finite element analysis, strain gauge, photoelastic and digital image correlation a way to analyze the biomechanical behavior in dental materials to obtain results that assist to obtain rehabilitations with favorable prognosis and patient satisfaction.

This study aimed to evaluate the influence of thermomechanical cycling (TMC) and type of abutment on the misfit and compressive strength of the implant–abutment interface. Forty 3.75-mm external hexagon implants with 25° angled abutments were divided into four groups (N = 10). Group A: overcast plus TMC; Group B: overcast without TMC; Group C: completely cast plus TMC; Group D: completely cast without TMC. Abutments were fixed to the implants with 32-Ncm torque, and groups A and C specimens were cyclically loaded at 80 N with 2 Hz for 1 million cycles. The misfit on the implant–abutment interface was evaluated by optical microscope (100×) and the compressive strength test was performed in a universal test machine. For statistical analysis, a two-way ANOVA and post hoc Tukey test were used. There was no difference in misfit presented by all the abutments in the absence of TMC (p > 0.05). When TMC was performed, the completely cast abutments showed greater misfit than overcast ones (p = 0.001). Regarding compressive strength, irrespective of TMC performed, the overcast abutments showed higher compressive strength values than completely cast abutments (p = 0.003). Moreover, disregarding the type of abutment used, the absence of TMC provided higher compressive strength values (p < 0.001). It was concluded that thermomechanical cyclic loading aggravated the misfit, especially in completely cast abutments, regardless of material or fabrication technique, and reduced the compressive strength of the two types of abutments tested.

This study aimed to evaluate the biomechanical behavior of Morse taper implants using different abutments (CMN abutment [(CMN Group] and miniconical abutments [MC Group]), indicated to support a screw-retained 3-unit fixed partial denture. For the in vitro test, polyurethane blocks were fabricated for both groups (n = 10) and received three implants in the “offset” configuration and their respective abutments (CMN or MC) with a 3-unit fixed partial denture. Four strain gauges were bonded to the surface of each block. For the finite element analysis, 3D models of both groups were created and exported to the analysis software to perform static structural analysis. All structures were considered homogeneous, isotropic, and elastic. The contacts were considered non-linear with a friction coefficient of 0.3 between metallic structures and considered bonded between the implant and substrate. An axial load of 300 N was applied in three points (A, B, and C) for both methods. The microstrain and the maximum principal stress were considered as analysis criteria. The obtained data were submitted to the Mann–Whitney, Kruskal–Wallis, and Dunn’s multiple comparison test (α = 5%). The results obtained by strain gauge showed no statistical difference (p = 0.879) between the CMN (645.3 ± 309.2 με) and MC (639.3 ± 278.8 με) and allowed the validation of computational models with a difference of 6.3% and 6.4% for the microstrains in the CMN and MC groups, respectively. Similarly, the results presented by the computational models showed no statistical difference (p = 0.932) for the CMN (605.1 ± 358.6 με) and MC (598.7 ± 357.9 με) groups. The study concluded that under favorable conditions the use of CMN or MP abutments to support a fixed partial denture can be indicated.

Maciel LC, et al. J Adv Prosthodont. 2020 Oct;12(5):291-298. https://doi.org/10.4047/jap.2020.12.5.291