The built-in water cooling device prevents overheating of the object and removes saw dust from the cutting edge and thus prolongs the lift time of the saw blade. The most favorable feed rate was determined (Fig. 3). After trimming, the first undefined slice was removed from the saw blade. The desired section thickness was selected, considering the thickness of the saw blade and added to the desired thickness of final section. The section was stabilized during the sawing process. To do so, a glass cover slip was glued onto the trimmed surface of the specimen block using cyanoacrylate glue. These blocks were cut with a low speed saw under water along the lateral surface of the implant. The implant bearing blocks were cut parallel to the long axis of the implant, and 30-μm-thick specimens were obtained.

The saw blade has a thickness of 280 μm and a feed of 310 μm was selected to obtain the final section thickness of 30 μm. The knurled screw was used for the setting of the section thickness. The prepared section was finally removed from the saw blade. The specimens were prepared for histology by the method as described by Donath and Breuner.

Histological evaluation

Subsequently, the sections were stained with toluidine blue and basic fuchsin similar to other studies. The specimen sections were evaluated at the most central saggital section of each implant under an optical microscope after staining. The images were photographed with a high resolution camera and interfaced to a monitor and PC, observed under the Leica DM2000 microscope, and the images were captured using Olympus DP72 camera and associated software. Bone implant contact (BIC) was measured using Infinity Analyze software. Six images of the same implant were taken and measurements were done. The percentage of the interface contact length between implant surface and bone, i.e., bone implant contact (BIC), was calculated. The percentage of bone tissue in a 200-μm-wide zone parallel to the contour of the implant area (adjoining the implant) was measured.

Micro-computed tomography (MicroCT)

MicroCT scans of each sample of both types of implants were obtained with a Skyscan 1172 equipment (Kontich, Belgium) at 6 μm resolution with 800 ms exposure time, 70 kV electric voltage, 167 μA current, and a 0.5-mm thickness aluminum filter. The equipment was fitted with a 1.3-MP camera to capture high resolution 2D images that were assembled into 3D reconstructions using NRecon software supplied with the instrument.

Statistical methods

Mean values and standard deviations were calculated for bone implant contact (BIC). Univariate analysis was done for all the evaluations. Analysis of variance (ANOVA) was used to analyze the differences between the two implants. P value <0.05 was considered significant. Statistical analyses were carried out with the help of SPSS statistical software version 18.