Evaluation of peri-implant tissues in implants placed sub-crestally after loading by clinical and microbiological methods

As an optional treatment for missing teeth cases, dental implants have increasing success ratios due to the developments in the implantology. These success ratios are effected by many factors. The microbial accumulation around the implant, draws attention in these factors, because it is pointed as foremost reason of implant loss. Microbial accumulation is highest at micro gap which is a space between implant and abutment parts. This micro gap which differentiates according to the connection shape, leads less imflammatory reaction in morse cone shaped connections than other types of connections. It has been reported that when morse cone dental implants are located at sub-crestal level, it provides more lasting peri-implant tissue support and implant success increase in long term. Accordingly, in this study, we aimed to see the influence of sub-crestal placement on microbiological changes after functional loading of dental implants.36 (18 test, 18 control) dental implants are included in this study. Clinical, radiographical and sub-gingival samples for microbiological analysis were collected at the day of functional loading and at the 1st, 3rd and 6th months. Microbiological samples were analysed by q-PCR.No statistical difference was observed between the groups in clinical, radiographical and microbiological compostion of periodontal pathogens. On the other hand, the total amount of bacteria at the 6th month was higher in control group, which is found statistically significant.According to results it is possible to mean sub-crestal placement provide beter peri-implant tissue barrier against microbial accumulation. But further long-term studies are needed