Healing at sites prepared using different drilling protocols. An experimental study in the tibiae of sheep

Abstract

The aim of the experiment was to study the healing at implants installed in site prepared in bone type 1 using different rotation speeds and cooling strategies. The tibiae of twelve sheep were used as experimental sites. Two implant sites were prepared in each tibia using drills either at a high or a mixed speed under irrigation. At the mixed-speed sites, 60 rpm without irrigation were applied for the last drill, the countersink and during implant installation. Biopsies representing the healing after 1, 2, and 6 weeks were obtained and ground sections were prepared. At the histological analyses, after 1 week of healing, no new bone was found at both high- and mixed-speed sites. After 2 weeks of healing, small amounts of newly formed bone were observed in the cortical layer, reaching percentages of 3.6±3.0% at the mixed-speed sites, and of 2.2±1.5% at the high-speed sites. An irrelevant quantity of new bone was seen in the marrow compartments of a few specimens. After 6 weeks of healing, new bone was found in higher quantity, reaching in the cortical compartment 66.9±6.8% and 67.3±17.7% at the mixed- and high-speed sites, respectively. The respective percentages in the marrow compartment were 23.2±13.0% and 30.6±29.2%. No statistically significant differences between high- and mixed-speed groups were found. It was concluded that the use of the last drill and the installation of the implant with or without irrigation yielded similar bone healing and osseointegration.

Infrared Thermographic Evaluation of Temperature Modifications Induced during Implant Site Preparation with Steel vs. Zirconia Implant Drill

“…For these reasons, it can be hypothesized that in clinical practice the temperature is superior to that observed in the present study. In fact, many factors that can influence the heat generation during the implant bed preparation including drilling speed [33,34], drilling depth [35], drill geometry [36,37], sharpness of the cutting tool [38], use of internal or external irrigation [39], use of graduated versus one-step drilling [40], intermittent versus continuous drilling and drill material [41] are controllable in clinical proactive, while the pressure applied to the drill [34] is not controllable.…”

Histological and Histomorphometrical Evaluation of a New Implant Macrogeometry. A Sheep Study

“…The dense implant-attached connective tissue, characteristic of a provisional connective tissue, was: continuous with the primary spongiosa, about 50 microns wide, rich in collagen fibers, and, probably, should be regarded as an osteoid which, during continued modeling, will transform into woven bone, and establish bone-to-implant contact [29].…”

The Effects of Liquid Disinfection and Heat Sterilization Processes on Implant Drill Roughness: Energy Dispersion X-ray Microanalysis and Infrared Thermography

“…The presence of abundant irrigation is fundamental to control this problem [9]. Heat generation during the implant bed preparation can be influenced by drilling speed [26], sharpness of the cutting tool [27], drilling depth [28], drill geometry [28,29], use of internal or external irrigation [30], use of graduated versus one-step drilling [31], intermittent versus continuous drilling and drill material [32]. All these variables are controllable in clinical practice, while the pressure applied to the drill is not controllable.…”