Peri-Implant Bone Resorption during Healing Abutment Placement: The Effect of a 0.20% Chlorhexidine Gel vs. Placebo-A Randomized Double Blind Controlled Human Study.

Introduction: Peri-implant marginal bone loss (MBL) seems to be more pronounced in the first year of loading despite all the studies and changes implemented to reduce it. Among the different causes, the presence of a microgap makes the interface between fixture and abutment colonizable by bacteria, causing an inflammatory response and consequent bone resorption. To reduce this several local antiseptics like chlorhexidine digluconate (CHX) were used after surgical procedures.

Aim: The objective was to radiologically compare the MBL when a 0.20% CHX gel or a placebo gel was applied to the implant-abutment interface during all surgical and prosthetic phases and for a follow-up period up to 12 months.

Method: 32 patients (16 for each Group A and B) were enrolled and rehabilitated with a single implant (Cortex classic, Cortex, Shalomi, Israel). During each of the clinical stages a gel containing 0.20% CHX (Plak ®Gel; Polifarma Wellness Srl, Rome, Italy) or a placebo gel (Placebo, Polifarma Wellness Srl, Rome, Italy) was used as indicated by the randomization chart. In order to compare radiographic modification intraoral radiographs was taken. Also, clinical data regarding implant or prosthetic failure and gingival index were recorded. Data were presented as means and standard deviations (SD) and used for the statistical analysis.

Results: All implants showed no bleeding on probing and a very small plaque score at the 1 year of follow-up. MBL was statistically significantly different between the groups in every stage.

Conclusion: Results obtained showed that the use of CHX gel inside the connection significantly reduces MBL during the first year. A rigid disinfection protocol with 0.20% CHX from the time of implant insertion to crown delivery is recommended to reduce host inflammatory response and consequently MBL. This trial is registered with ClinicalTrials.gov Identifier: (Registration Number: NCT03431766).