Please activate JavaScript!
Please install Adobe Flash Player, click here for download
ePaper created 2016-03-07, 22:38:59 | version 1.38.0
Volume 2 | Issue 1/2016 17 Journal of Oral Science & Rehabilitation I m pla nt po si ti o ni ng wi thi n e xtracti o n so cke ts Histologic a l prepa ra tion Individual blocks containing the implant and the surrounding hard and soft tissue were collected from the mandible and fixed in a 4% formalde- hyde solution. The specimens were subse- quently dehydrated in a series of graded ethanol solutions and finally embedded in resin (LR White, hard grade, London Resin, Reading, UK). Theblockswerecutalongthebuccolingualplane using a diamond band saw fitted in a precision slicing machine (EXAKT 300, EXAKT Advanced Technologies, Norderstedt, Germany) and then reduced to a thickness of approximately 60 μm usingacuttingandgrindingdevice(EXAKT400, EXAKTAdvancedTechnologies).Thehistological slides were stained with Stevenel’s blue and alizarin red and examined under a standard light microscopeforhistometricanalysis. Histolo gic a l eva lua tion Under an Eclipse Ci microscope (Nikon, Tokyo, Japan),connectedtoacomputerthroughavideo camera(NikonDigitalDS-Fi2,Nikon),thefollow- ing landmarks were identified (Fig. 3): the im- plant shoulder (IS), the top of the adjacent bony crest (C), the most coronal point of contact be- tween the bone and implant (B), the top of the mucosal margin (PM),the surface ofthe implant at the top ofthe threads (S), the outer contour of the bony crest (OC) and the outer contour of the periimplant mucosa (OM). The following meas- urements were performed using NIS-Elements software(Version4.1;Nikon,Tokyo,Japan)under 40× magnification: the vertical distance be- tween IS and C, IS and B, as well as PM and IS. PM–Bwascalculatedfromthedataavailable. Under 40× magnification, the width of the alveolarbonycrestwas measured from Sto OC at the IS level (0 mm) and then apical to it at each subsequent millimeter, up to 5mm (Fig. 3). The width of the periimplant mucosa was measured at the IS level (0 mm) and then up to 3 mm coronal to the abutment surface and up to 3 mm apicalto it, from S. Under 100× magnification, the percentage of bone-to-im- plant contact (BIC%)was evaluatedfromthe IS to the apical extension of the implant, both buccally and lingually. Data analysi s Mean values and standard deviations, as well as the 25th , 50th (median) and 75th percentiles,were calculated for each outcome variable. Differ- ences between buccally (B-sites) and lingually (L-sites) positioned implants were analyzed us- ing the Wilcoxon signed-rank test for paired ob- servations using IBM SPSS Statistics for Win- dows (Version 19.0; IBM Corp., Armonk, N.Y., U.S.). The vertical level of the bony crest and os- seointegration (IS–C and IS–B) were the main outcome variables. The level of significance was setatα = 0.05. Results In one animal, a fracture of the buccal wall of the alveolusoccurredduringextractionandtheanimal was excluded entirely from analysis. No artifacts were generated during histological processing, nor were any tissue blocks destroyed. Hence, the B- and L-sites yielded n = 7. In the text, mean values ± standard deviations are reported, andinthetables,themediansandthe25th and75th percentilesareincludedtoo. Fig. 3 Fig. 3 Landmarks used for histomorphometric analyses: IS: implant shoulder; C: top of the adjacent bony crest; B: most coronal point of contact between the bone and implant; PM: top of the mucosal margin; S (dashed green line): the surface of the implant at the top of the threads; OC (dashed yellow line): the outer contour of the bony crest; OM (dashed blue line): the outer contour of the periimplant mucosa. Volume 2 | Issue 1/201617