Silver-chlorexidine-liquid is effective to sterilize screw retaining abutment to implant space in already inserted fixture: An in vitro study

Contamination of screw retaining abutment to implant space (SRAIS) creates an infected room at the implant abutment junction (IAJ) that can cause or maintain peri-implantitis. Aim of the present study is to determine whether the treatment of SRAIS with silverclorexidine liquid (named SBC-40) is able to sterilize SRAIS. Materials and methods: A total of eight implants were used (Edierre Implant System, Edierre SpA, Genova, Italy). The SRAIS of four fixtures were firstly contaminated with 10 micro-litres of pure bacteria (i.e. genetically modified Escherichia coli). Subsequently SRAIS were treated with SBC-40 for 20 seconds and then replaced with Lysogeny Broth (LB). The remaining four implants were just filled with LB. Abutment were then screwed. All 8 fixtures were placed in tubes and immerged in LB plus E. coli to cover outer implant-abutment junction (IAJ). After 24 hours IAJ were opened and liquid collected from SRAIS by using paper tips. Same sampling was performed in LB out of implants. The tips were immerged in sterile LB and bacteria viability was determined by measuring their Optical Density (OD) at three time points. Results: In untreated implants, bacteria grew (internally and externally) for the first 48 hours but subsequently they started to die. In treated implants, instead, bacteria grew just in the space surrounding fixtures suggesting that, even if bacteria were able to enter in SRAIS, they immediately died, thanks to the presence of SBC-40. Conclusions: SBC-40 is potentially able to sterile the SRAIS in fixtures already inserted in patients.