Quantitative histology of periimplant bone: confocal-laser-scanning-microscopy (CLSM) and conventional-light-microscopy (LM)

Objectives: The standard technique for the histologic evaluation of dental implants is light microscopy of stained thin sections. A less time and resources consuming method was recently introduced using CLSM. The aim of this study was to validate the histo-morphometry of the amount of periimplant bone in 1) non- decalcified, unstained bone-implant blocks using CLSM in reflection mode and 2) stained thin sections using the standard sawing/grinding technique and conventional transmission light microscopy. Methods: 69 dental implants (6 different types) implanted in the mandible and maxilla of beagle dogs were used. The non-decalcified, unstained blocks were studied by CLSM (Leica) in reflection mode (633nm) as described earlier (Al-Nawas et al. 2004). Subsequently the samples were grinded (to 70µm), stained with hematoxillin and eosine and conventional light microscopy was performed. The quantitative amount of mineralised hard tissue was calculated for an area surrounding 45, 75, 150, 225 and 300 µm around the implant using two different thresholds. Results: The mean and standard deviation of the area of mineralised bone around the implants is given for each method (LM & CLSM at high and low threshold) and at the different width around the implants: Conclusions: A high threshold for the image segmentation resulted in bone to implant contact rates which were not statistically different from the light microscopy method. The less time consuming CLSM technique in reflection mode can be used as a semi-automatic, standard technique for quantitative analysis of the bone to implant contact.