Introduction

Dental implants represent a well-established and highly predictable treatment modality for restoring esthetic, functional, and phonetic deficiencies within the oral cavity. In implant therapy, early success is primarily determined by the achievement of primary stability, followed by secondary osseointegration after placement within the jawbone [1-3]. Long-term success, however, relies on the preservation of sufficient peri-implant bone volume and quality, ensuring the ability to withstand functional loads transmitted through the prosthetic restoration [1].

Adequate bone availability at the intended implant site is a critical prerequisite for both immediate and long-term treatment outcomes [3]. For optimal osseointegration, the implant surface must be completely surrounded by bone. Any deficiency in bone-to-implant contact may impair early integration and increase the risk of long-term failure [2].

Following successful osseointegration, biofilm-associated peri-implant diseases represent one of the most common biological complications. Clinically, these conditions are characterized by bleeding on probing and/or suppuration, accompanied by progressive bone loss [4]. Their prevalence varies depending on diagnostic criteria, follow-up duration, and patient-related risk factors [3,4].

This clinical challenge is closely linked to implant design. Moderately rough titanium surfaces, such as sandblasted, large-grit, acid-etched (SLA) surfaces, improve osseointegration but may also favor plaque retention once exposed to the oral environment [5-7]. In peri-implant defects, implant threads, undercuts, and limited access areas can shelter bacterial biofilm from mechanical instruments, antiseptics, and irrigating solutions, leading to residual contamination even after thorough debridement [8,9].

Conventional mechanical debridement techniques, including hand instruments, ultrasonic devices, and air-abrasive systems, can reduce biofilm load but often fail to achieve complete decontamination. These approaches may also induce minor alterations to the implant surface [5,10]. Consequently, alternative or adjunctive decontamination strategies have been investigated.

Chemical antiseptics, laser-based therapies, and electrochemical approaches have been proposed for implant surface decontamination; however, no universally accepted protocol exists [10-12]. Among emerging technologies, electrolytic cleaning systems have been introduced as novel approaches aiming to disrupt biofilm through electrochemical reactions and potentially enhance surface wettability, which may improve decontamination efficacy [6-8]. Given these limitations, well-controlled experimental models using standardized implants, contamination protocols, and outcome assessments are needed to better compare the antimicrobial performance of different decontamination strategies. Therefore, the comparison of these different treatment modalities is clinically relevant, as they represent distinct mechanisms currently investigated for managing biofilm contamination on implant surfaces.

The efficacy of decontamination strategies is commonly assessed by quantifying bacterial reduction, typically expressed as colony-forming units (CFU), with results often reported on a logarithmic scale (log10CFU) to allow standardized comparison of microbial load [13-15].

Therefore, the aim of this in vitro study was to evaluate and compare the antimicrobial efficacy of different peri-implant decontamination modalities, including 0.12% chlorhexidine (CHX), GalvoSurge electrolytic cleaning, and erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser irradiation, against Staphylococcus aureus biofilm formed on Straumann SLA tissue-level implants mounted in a custom peri-implant defect model. The primary outcome was bacterial reduction expressed as log10(CFU/implant), whereas the standardized implant model and biofilm contamination protocol were used as methodological approaches to ensure controlled comparison between treatment groups. The null hypothesis was that no significant difference in log10(CFU/implant) would be observed among the untreated control, CHX, GalvoSurge, and laser treatment groups.