Characterization of bacterial biofilms developed on the biodegradable polylactide and polycaprolactone polymers containing birch tar in an aquatic environment.

Birch tar was added to polylactide (PLA) and polycaprolactone (PCL) to create films with antimicrobial properties. After incubating the films for seven days in lake water, the diversity of bacterial communities developed on the surfaces of PCL and PLA with embedded birch tar (1 %, 5 %, and 10 %, w/w) was assessed with amplicon sequencing of the 16S rRNA gene on a MiSeq platform (Illumina). Notably, Aquabacterium and Caulobacter were more abundant at the surface of PCL compared to PLA (13.4 % vs 0.2 %, p < 0.001 and 9.5 % vs 0.2 %, p < 0.001, respectively) while Hydrogenophaga was significantly more abundant at the surface of PLA compared to PCL (6.1 % vs 1.8 %, p < 0.01). Overall, lower birch tar concentrations (1 % and 5 % on both polymers) stimulated bacterial diversity in biofilms compared to the control. The number of reeds assigned to Flavobacterium and Aquabacterium showed a rising trend with the increase of birch tar concentration on the surface of both polymers.

Digital intraoral scanner devices: a validation study based on common evaluation criteria.

BACKGROUND: The evolution of intraoral scanners (IOSs) is rapid, and new IOSs appear on the market with different properties depending on the manufacturers. There is no uniform rating system based on a defined set of aspects that has reported in the literature that can be used to compare these devices. This validation study aimed to compare different IOSs based on objective and comprehensive parameters. METHODS: In this study, 12 different IOSs were examined. The IOSs that were tested in this study in order of their delivery included the 3Shape Trios 3 Pod®, Planmeca Emerald®, Straumann DWIO®, GC Aadva®, iTero Element 2®, CEREC Primescan®, Medit i500®, 3Shape Trios 4 Move®, Carestream CS3600®, 3Shape Trios 4 Pod®, Carestream CS3700®, and Planmeca Emerald S®. IOSs were evaluated in four different ways: (a)summary chart, (b)comparative assessment, (c)data based on in vitro measurements and (d)accuracy measurements. A scoring system was created to enable an objective rating of IOSs. RESULTS: The differences among IOSs were demonstrated in point scores (summary chart[max. 10 points] + weight of IOSs[max. 2.5 points] + circumference of IOSs[max. 2.5 points] + in vitro scanning time[max. 2.5 points] + pauses in data capture[max. 2.5 points] + accuracy[max. 10 points] = summary[max. 30 points]). Trios 4 Pod achieved the greatest cumulative score (23.37 points), furthermore it earned the highest points for summary chart and scanning speed. Regarding scanning continuity, the best-performing IOSs, which tied at identical point scores, were the Trios 3 and 4 Pod, Trios 4 Move, iTero Element 2, CS3600 and CS3700. The most accurate IOS was the CEREC Primescan, although it earned the lowest points of the comparative assessment (heaviest IOS). GC Aadva scored 5.73 points of a maximum of 30 points, which was the poorest result in this study. CONCLUSION: The scoring system reflects the differences among IOS devices based on the evaluated objective parameters and can be used to help clinicians select the right IOS device. The new generations of IOSs have more special properties, and their accuracy is higher than the previous versions. Trial registration The permission for this study was granted by University Ethics Committee of Semmelweis University (SE RKEB number:108/2019).

Comparing the effectiveness of shade measurement by intraoral scanner, digital spectrophotometer, and visual shade assessment.

OBJECTIVE: Trios3 (3Shape, Denmark) intraoral scanner is complete with a tooth shade measurement function, but there is limited information about its efficacy. This in vivo study aimed to evaluate this function in relation to visual and spectrophotometric shade determination. MATERIALS AND METHODS: Ten dental students from Semmelweis University determined tooth shade for 10 volunteers using Vita A1-D4 (VC) and Vita Linearguide 3D-Master (LG) guides, Vita Easyshade spectrophotometer (ES) and Trios 3 intraoral scanner (TR). First and last patient was always the same (Patient R). Intrapersonal repeatability was calculated. Four selected shades of each tooth were presented to student, supervisor, and patient to select best match. Selection percentages were calculated. The supervisor's best match was the reference (∆E00 ). RESULTS: Median ∆E00 of Patient R: TR 1.09; VC 1.5; ES 2.35; LG 3.1. The percentages of best match: VC 16.7%.; TR 21.64%; ES 26.58%; LG 34.08%. Median ∆E00 of students' and supervisor's best match: LG 2.73; ES 4.29; TR 4.29; VC 16.35. TR was the most repeatable. The most "best-match shade tabs" were selected using LG. VC shade tabs was the least consistent with the examined teeth. CONCLUSIONS: TR can be used for shade selection with a 3D-Master tooth color system with visual verification. CLINICAL SIGNIFICANCE: Correct tooth shade determination is one of the most important step in making esthetic restorations. New shade matching systems have been developed to surpass the visual method of shade determination. There are new intraoral scanners with built-in shade measurement functions. Digital shade determination methods are more independent from the environmental circumstances, and with intraoral scanners, it is easy to measure the tooth shade by taking a digital impression at the same time. These new devices may be a reliable alternative method for shade selection with visual verification.