Impact of plasma of argon cleaning treatment on implant abutments in patients with a history of periodontal disease and thin biotype: radiographic results at 24-month follow-up of a RCT

Background: A lack of evidence is present in literature regarding the clinical relevance of micropollution and bacterial contamination present on customized titanium abutments following laboratory stages and steaming cleaning procedures. To preserve abutments from such pollutants, plasma of argon cleaning of customized abutments was advocated. Aim: The aim of this prospective, randomized, match-paired, triple-blinded, controlled, clinical trial is to longitudinally assess radiographical marginal bone-level changes around implants restored according to the platform switching and "one-abutment-one-time" concepts, using commercially available abutments, with and without plasma of argon cleaning treatment after customization. Materials and methods: Thirty patients with thin gingival biotype, a history of periodontal disease, and in general good health received one implant in the anterior maxilla or premolar region. Patients were randomly assigned to control (abutment subjected only to usually adopted cleaning protocol by steam) and test group (abutment subjected to plasma of argon treatment). Periapical standardized digital radiographs were taken at the time of crown connection (T0), 6 (T1) and 24 months after the final restoration (T2). Average mesial-distal bone-level changes mean values with standard deviations (SD) were calculated. The Mann-Whitney U-test was selected to identify differences in bone-level changes between test and control groups. Results: An average interproximal bone loss of 0.16 mm (SD: 0.17) and 0.07 mm (SD: 0.34) was revealed in the control and test group at 6 months (T1), respectively, while after 24 months, groups showed a mean bone-level changes of 0.38 mm (SD: 0.44) and 0.11 mm (SD: 0.14), respectively. Statistically significant differences among control and test groups were found at both time points. Intergroup comparison relived absence of statistically significant difference. Conclusion: Plasma-cleaning treatment of implant titanium abutments, together with platform switching and one-abutment-one-time concepts, could be favorable in terms of hard-tissue-level changes, also in critical conditions such as in patients with a history of periodontal disease, presenting thin gingival biotype.