Cleaning effects of decontamination methods on clinically failed TiUnite implants and their impacts on surface roughness and chemistry: An in vitro pilot study.

To evaluate the in vitro cleaning effects of different decontamination methods and their impacts on surface characteristics using clinically failed TiUnite implants (Nobel Biocare, Kloten, Switzerland).Thirty clinically failed TiUnite implants were treated using different decontamination methods. Group 1 (control group) received physiological saline irrigation; Group 2 underwent erythritol powder air polishing (AIRFLOW Master Piezon, EMS Dental, Nyon, Switzerland); Group 3 was treated with erythritol powder air polishing with ethylenediaminetetraacetic acid brushing (FileRite PRC, Pulpdent, Watertown, MA, USA); Group 4 received ultrasonic scaling with polyetheretherketone tips (EMS Dental); Group 5 underwent ultrasonic scaling with polyetheretherketone tips with ethylenediaminetetraacetic acid; and Group 6 was treated with a combination of ultrasonic scaling with polyetheretherketone tips, erythritol powder air polishing and ethylenediaminetetraacetic acid. Surface cleaning effects, quantified by relative contaminated area reduction and visual analogue scale score, as well as surface roughness and chemistry, were assessed after decontamination. The cleaning effects of each decontamination method were also compared between TiUnite and SLA (sandblasted, large-grit acid-etched; Straumann, Basel, Switzerland) implants.Group 6 showed the highest relative contaminated area reduction (stereoscopic microscopy 83.92%, scanning electron microscopy 96.40%), visual analogue scale score (2.83) and reduction in surface roughness (thread bottom -0.78 μm, tip -1.35 μm), as well as an almost maximal decrease in the proportion of carbon (thread bottom -12.33%, tip -8.77%) and increase in that of titanium (thread bottom 13.71%, tip 10.73%). Polyetheretherketone remnants were observed in Groups 4 and 5 but appeared to be reduced in Group 6. When comparing the outcomes with those for SLA implants, no significant differences were found.Within the limitations of the present study, the combination of ultrasonic scaling with polyetheretherketone tips, erythritol powder air polishing and ethylenediaminetetraacetic brushing achieved reasonable cleaning effects. The original surface modification did not seem to have any impact on the decontamination results for any of the methods examined.