Band saw 300 cl

Transvers microradiography was used to assess mineral loss (ΔZ (vol% × μm)) and lesion depth (LD (µm)). Detailed descriptions of this methodology can be found elsewhere [26 (link)]. The samples were cut perpendicularly to the test surface (Band Saw EXAKT 300 CL) and ground flat to 100 ± 10 μm (EXAKT Mikroschleifsystem 400 CS; EXAKT; abrasive paper WS flex 18 C; SiC; P 1200–4000; Hermes Schleifmittel, Hamburg, Germany). Samples were imbibed in 99% ethylene glycol (Sigma Aldrich, Steinheim, Germany) and transferred to the X-ray source. Microradiographs were obtained using a nickel-filtered copper X-ray source (X-ray tube PW2213/20; Panalytical, Kassel, Germany; x-ray generator PW 1730/10; Philips, Eindhoven, The Netherlands) operating at 20 kV and 10 mA with an exposure time of 10 s. Films (Fine 71337; Fujifilm, Tokyo, Japan) were developed according to manufacturer’s recommendation. A digital-image-analysing system (CFW 1312M; Scion, Frederick, MD, USA), interfaced with a universal microscope (CCD-video camera module XC 77 CE; Sony, Tokyo) and dedicated software (TMR for Windows; Version 2.0.27.2; Inspektor Research, Amsterdam, The Netherlands) was used to analyze the lesions.

For this study, we have used bovine incisors, which were obtained from a local slaughterhouse (VION, Bad Bramstedt, Germany, vionfoodgroup.com). The samples had originally not been collected for the purpose of research, but were obtained after slaughtering as described in previous publications, without ethical approval being seeked [12] (link). Extraction of incisors was performed under supervision of the local veterinary, and teeth were only utilized after being declared free of infectious diseases. From each of 32 bovine incisors of the second dentition, 4 axial root slices (5 mm height) were cut (Band Saw Exakt 300cl, Exakt Apparatebau, Norderstedt, Germany) and embedded in acrylic resin (Technovit 4071, Heraeus Kulzer, Hanau, Germany). Embedded slices were then ground flat into cubicles (Phoenix Alpha; Buehler, Düsseldorf, Germany), plan-parallelised, and polished (abrasive paper 1200, 2400, 4000 Exakt Apparatebau) under water cooling. Two thirds of the resulting exposed dentin surface (3×5 mm) were covered with a tape, and the complete dentin surface was covered with acid-resistant nail varnish (Maybelline, New York, USA). The tape was then carefully removed with a scalpel, resulting in a defined experimental area, which was then controlled using a stereomicroscope (Stemi, Zeiss, Jena, Germany).

Thirty bovine incisors of the second dentition where obtained from a local slaughterhouse (VION, Bad Bramstedt, Germany, vionfoodgroup.com). Extraction of the teeth was performed after slaughtering under supervision of the local veterinary. From the roots of the teeth, 100 dentin specimens (5 × 3 × 2 mm, Figure 2) were prepared (Band Saw Exakt 300 CL, Exakt Apparatebau, Norderstedt, Germany), ground flat (LaboPol 25, Struers, Ballerup, Denmark/Willich, Germany) and polished (abrasive paper SiC, P 1000–4000, Buehler, Düsseldorf, Germany). Twenty-five specimens per group were transferred into a silicone mold and embedded within acrylic resin (Technovit 4071, Heraeus Kulzer, Hanau, Germany). A 1 × 3 mm reference strip was covered with nail varnish (Long Lasting Nail Colour, Rival de Loop, Berlin, Germany), leaving an uncovered dentin surface of 4 × 3 mm. The resulting four carrier bars were sterilized (121 °C, 2.1 bar, 20 min, Tuttnauer 3870 ELV, Biomedis, Gießen, Germany).