New design of interdental rubber picks - does the archimedean screw design bring an improvement for experimental cleaning efficacy and force?

BACKGROUND: Up to date, interdental brushes (IDB) are the first choice for interdental cleaning because of their cleaning efficacy. Cylindrical ones must be selected individually according to the size/morphology of the interdental area (IDR), whereas conical ones cover a larger variability of IDR. However, there is a trend on the part of patients towards interdental rubber picks (IRP) which are in general conically shaped, and which seem to be linked with lower cleaning efficacy. A new IRP with an Archimedes´ screw design was developed to overcome this limitation. Therefore, the in vitro study aimed to measure the experimental cleaning efficacy (ECE) and force (ECF) during interdental use of IDBs versus the new IRP type. METHODS: Three IRPs with different tapers (PHB angled: 0.039, PHB straight S: 0.027, Vitis straight M: 0.045; all Flexipicks, Dentaid, Cerdanyola del Vallès, Spain) were compared to one IDB (Interprox micro PHD 0.9, Dentaid, Cerdanyola del Vallès, Spain). IDR were reproduced by a 3D-printer (Form2, Formlabs Sommerville, MA, USA) according to human teeth and matched to equivalent pairs (isosceles triangle, concave, convex) in three different diameters (1.0 mm,1.1 mm,1.3 mm). Covered with simulated biofilm, pre-/ post-brushing situations of IDR (standardized, computer-aided ten cycles) were photographed and quantified by digital image subtraction to calculate ECE [%]. ECF were registered with a load cell [N]. Statistically significant differences were detected using the Mann-Whitney-U-test and the Kruskal-Wallis-test with Bonferroni correction for multiple testing. RESULTS: Overall, the ECE (mean ± SD) was higher for IDB micro 0.9 (45.95 ± 11.34%, p < 0.001) compared to all IRPs (PHB angled: 25.37 ± 15.29%; PHB straight: 22.28 ± 16.75%; Vitis straight: 25.24 ± 12.21%; p ≤ 0.001), whereat best ECE was achieved in isosceles triangle IDR of 1.0-1.1 mm (IDB micro 0.9: 70.7 ± 7.7%; PHB angled S: 57.30 ± 4.43%; p < 0.001). The highest ECF occurred for Vitis straight M with 2.11 ± 0.46 N, while IDB micro 0.9 showed lowest ECF values (0.64 ± 0.14 N; p < 0.001). CONCLUSIONS: IRP with an Archimedes´ screw design and a higher taper were associated with advanced ECE but also higher ECF, nevertheless, ECE didn't reach the cleaning efficacy of conventional IDBs.

Influence of flow rate and different size of suction cannulas on splatter contamination in dentistry: results of an exploratory study with a high-volume evacuation system.

OBJECTIVES: SOPs recommend high-volume evacuation (HVE) for aerosol-generating procedures (AGPs) in dentistry. Therefore, in the exploratory study, the area of splatter contamination (SCON in %) generated by high-speed tooth preparation (HSP) and air-polishing (APD) was measured when different suction cannulas of 6 mm diameter (saliva ejector (SAE)), 11 mm (HC11), or 16 mm (HC16) were utilized versus no-suction (NS). MATERIALS AND METHODS: Eighty tests were performed in a closed darkened room to measure SCON (1m circular around the manikin head (3.14 m2) via plan metrically assessment through fluorescence technique. HSP (handpiece, turbine (Kavo, Germany)) or APD (LM-ProPowerTM (Finland), Airflow®-Prophylaxis-Master (Switzerland)) for 6 min plus 5 s post-treatment were performed either without suction or with low-flow (150 l/min for SAE) or high-flow rate (250 l/min/350 l/min for HC11/HC16) suction. All tests were two-tailed (p≤0.05, Bonferroni corrected for multi-testing). RESULTS: Irrespective the AGP, SCON was higher for NS (median [25th; 75th percentiles]: 3.4% [2.6; 5.4]) versus high-flow suction (1.9% [1.5; 2.5]) (p=0.002). Low-flow suction (3.5% [2.6; 4.3]) versus NS resulted in slightly lower but not statistically significantly lower SCON (p=1.000) and was less effective than high-flow suction (p=0.003). Lowest contamination values were found with HC16 (1.9% [1.5; 2.5]; p≤0.002), whereat no significant differences were found for HC11 (2.4% [1.7; 3.1]) compared to SAE (p=0.385) or NS (p=0.316). CONCLUSIONS: Within study's limitations, the lowest splatter contamination values resulted when HC16 were utilized by a high-flow rate of ≥250 l/min. CLINICAL RELEVANCE: It is strongly recommended to utilize an HVE with suction cannulas of 16mm diameter for a high-flow rate during all AGPs and afterwards also to disinfect all surface of patients or operators contacted.