Clinical and laboratory evaluation of the effects of different treatment modalities on titanium healing caps: a randomized, controlled clinical trial

Objectives The objective of this study is to evaluate the effects of treatment modalities on titanium surface characteristics and surrounding tissues. Materials and methods Eighteen participants each had four titanium healing caps (HC) attached to four newly inserted implants. After healing, each HC was randomly assigned to either (1) titanium curettes (TC), (2) stainless steel ultrasonic tip (PS), (3) erythritol air-polishing powder (EP), or (4) only rubber cup polishing (CON). Probing depths (PD), bleeding on probing (BOP), matrix metalloproteinase 8 (MMP-8), and periopathogens were recorded before and 3 months following instrumentation. After final assessments, HCs were removed, cleaned, and subjected to (a) bacterial colonization ( Streptococcus gordonii , 24 h; mixed culture, 24 h) and (b) gingival fibroblasts (5 days). HC surfaces were analyzed with a scanning electron microscope (SEM). Results No significant differences between the groups were evident before or after instrumentation for PD and BOP (except TC showed a significant decrease in PD; p = 0.049). MMP-8 levels and bacterial loads were always very low. MMP-8 decreased further after instrumentation, while bacteria levels showed no change. No significant differences ( p > 0.05) were evident in bacterial colonization or fibroblast attachment. A comparison of the overall mean SEM surface roughness scores showed a significant difference between all groups ( p < 0.0001) with the lowest roughness after EP. Conclusions All treatments performed yielded comparable outcomes and may be implemented safely. Clinical relevance Clinicians may fear implant surface damage, but all instrumentation types are safe and non-damaging. They can be implemented as needed upon considering the presence of staining and soft and hard deposits.