In vitro Analysis of Abutment Debridement-efficacy and Surface-alteration Following Various Instrumentations

Objectives: To qualitatively and quantitatively assess changes in surface roughness, topography and alterations to elemental composition of titanium and zirconia abutments following instrumentation with various modalities. To quantitatively assess the debridement efficacy of these modalities.
Methods: 18 titanium and 18 zirconia commercially-available abutments were mounted into a newly-developed mucositis model. Twelve treatments were examined in triplicates including: (1) air-polishing with glycine powder, (2, 3) air-polishing with erythritol powder – 2 settings, (4) prophylaxis cup and paste, (5) plastic curette, (6) titanium curette, (7) stainless steel (SS) curette, (8) titanium ultrasonic tip, (9) polyether ether ketone (PEEK) sonic tip, (10) PEEK ultrasonic tip, (11) SS sonic tip, (12) SS ultrasonic tip. All modalities were applied for 20 seconds except for the air-polishing with Erythritol which was trialled for 5 and 20 seconds. Baseline and post-treatment analyses were completed using stereoscopic microscopy, scanning electron microscopy (SEM), vertical scanning interferometry (VSI), and energy-dispersive x-ray spectroscopy.
Results: None of the treatments changed the roughness values of titanium abutments significantly compared to baseline after adjusting P values for multiple comparisons. SS ultrasonic tip and ultrasonic titanium tip were associated with significantly lower roughness at the coronal (adj P<0.05) aspects of the zirconia abutments. Despite a lack of numerical roughness change, SEM and VSI reconstructions revealed substantial scratching and gouging of the titanium abutments’ surface following all instrumentations with the exception of air-polishing devices. While zirconia’s topography was unaltered, resultant surface residues occurred following instrumentation with all devices except for air-polishing with erythritol powder. Furthermore, surface elemental composition was altered by treatment with SS and titanium devices. No modality achieved 100% efficacy with residual plaque present on the apical third of all abutments’ surfaces.
Conclusions: Air-polishing devices had the highest probability for providing both optimal debridement efficacy and maintaining surface properties.