To evaluate the colour stability and surface roughness of 3 different CAD/CAM materials (IPS e.max, Vita Enamic, and PEEK) after immersion in two beverage solutions (Coffee, Coca-Cola). Methodology: Samples from a lithium disilicate glass-ceramic (IPS e.max CAD), a hybrid ceramic (Vita Enamic), and PEEK (BioHPP) were evaluated for colour change and surface roughness under immersion in two beverage solutions (Coffee, Coca-Cola). A total of 30 samples were prepared n=10 each. Spectrophotometer analysis was used to measure colour parameters (a*, b*, c*) before and after the immersion cycles and the average colour difference (Delta E*) was calculated after immersion in different beverages. Surface roughness was measured with a non-contact profilometer. Statistical analysis was performed using the Kruskal Wallis test with the Mann Whitney test as posthoc. The significance level was set at P ≤ 0.05. Results: There was a significant colour change between the materials. Vita Enamic and PEEK samples showed the highest colour change value with coffee immersion (ΔE) (7.96± 3.86), (6.07± 3.12) respectively. While IPS e.max. CAD revealed the lowest colour change value (2.62 ±1.54) following coffee immersion with a statistically significant difference in between (P< 0.011). After immersion in different media, there was a significant difference in surface roughness between the materials (p< 0.05). Conclusion: Vita Enamic and PEEK showed colour change beyond the clinically acceptable level, while IPS e.max CAD was the most stable material in colour and surface roughness.

The introduction of single-file nickel-titanium (NiTi) reciprocating systems has been a major breakthrough in the field of endodontics. Thus, the aim of this study was to compare the available reciprocating systems, Reciproc and WaveOne, using a meta-analysis with different parameters. A comprehensive electronic literature search for Reciproc and WaveOne using PubMed and Google scholar was initially conducted in September 2014 and updated in September 2016. Inclusion and exclusion criteria were then established. Twenty-six studies were qualified for the systematic review, and only three studies were considered for the meta-analysis using cyclic fatigue resistance as the main parameter. The time to fracture for the Reciproc and WaveOne systems ranged from 119.7 sec to 156.4 sec and 74.8 sec to 99.6 sec, respectively. The pooled difference in mean time to fracture was longer for the Reciproc system by 45.6 sec. This difference was statistically significantly at P value < 0.001. In conclusion, our study supports the finding that Reciproc is more resistant to cyclic fatigue than WaveOne. However, with regard to other parameters, mixed results were obtained. Well-designed randomized clinical trials comparing both systems under the same experimental conditions should be done in future studies.