The aim of a successful surgical peri-implantitis treatment is to resolve inflammation, decrease the bone defect, and limit peri-implant soft tissue recession [10,11,12]. The choice of surgical technique mostly depends on the defect morphology [10, 12, 20]. In the presence of horizontal bone loss, access flap or resective surgical techniques are indicated to sustain peri-implant tissue health and stable marginal bone levels. Reconstructive techniques for peri-implantitis treatment is indicated in 3-wall or circumferential defects with an intrabony component of 3 mm or more and an adequate keratinized mucosa around [11, 13]. Therefore, Class I and III peri-implantitis defects having at least 2 mm of keratinized tissue were included in the study.

During surgical treatment of peri-implantitis, implantoplasty has been suggested as an adjunctive measure to create a smooth surface to reduce biofilm accumulation [12]. Although this approach improved clinical and radiographic parameters significantly, it has also been associated with significant soft tissue recession, exposure of the implant surface, a limited esthetic outcome, and the implant corrosion [12, 21]. The anti-bacterial and anti-inflammatory effects of the chitosan brush have been shown in previous studies for the treatment of peri-mucositis and non-surgical peri-implantitis treatment [7, 8, 22]. However, no study has been conducted regarding the effectiveness of the chitosan brush in the surgical treatment of peri-implantitis for surface decontamination. Most of the previous studies that aimed to reconstruct the peri-implantitis defects used titanium curettes. The results of the present study are in line with those of previous studies reporting PD reductions around 3 mm and radiographic defect fill ranging between 1 and 5 mm within 1 year following the reconstructive peri-implantitis treatment [16, 17, 23, 24].

In a clinical study that used xenograft and collagen membrane in the surgical treatment of intra-bony peri-implant defects following the use of a rotary titanium brush, PD values reduced from 4.72 ± 1.02 to 3.18 ± 0.54 at 6-month follow-up [24]. In another study [25] that used a rotating titanium brush for decontamination, PD reduced by 2.92 ± 1.73 mm following deproteinized bovine bone mineral with 10% collagen application to defects at 1-year follow-up with improvements in BoP scores.

Previous studies have indicated that cone beam computed tomography (CBCT) has better sensitivity for fenestration and dehiscence defects but also has a tendency to underestimate or overestimate the size of defects compared to periapical radiographs. Moreover, periapical radiographs revealed better specificity in detecting peri-implant bone defects compared to computed tomography [19]. It was concluded that periapical radiographs should be used as a favorable method for peri-implant bone loss evaluation. [24, 25].

Successful surgical peri-implantitis treatment is defined as PD values around implant ≤ 5 mm, without suppuration and BoP and radiographic defect fill ≥ 1.0 mm [10, 20]. In the literature, several factors have been listed to influence treatment success negatively. One of those factors is inadequate post-operative plaque control [11, 12, 15, 26]. In order to eliminate the negative effects of the dental biofilm accumulation, the included patients were screened at 1-, 3-, 6-, and 12-month follow-ups for supragingival professional prophylaxis. FMPS remained below 10% throughout the post-operative period, which may explain the significant reductions of BoP and lack of suppuration in the present study results in addition to treatment success.

Given its limitations, including a limited number of treated peri-implantitis defects and the absence of a control group due to its case series design, one should interpret the present study findings with caution. Moreover, longer follow-up periods may be beneficial to determine the precise impact of this treatment approach and to evaluate the long-term stabilization of the graft material.

In conclusion, reconstructive treatment of peri-implantitis with the use of xenograft + resorbabale collagen membrane combination together with the chitosan brush for surface decontamination provided significant improvements in clinical and radiographic parameters and may be an effective treatment protocol. However, randomized, controlled, clinical trials with proper sample size calculations are required to compare the efficacy of different treatment modalities on different implant surface characteristics. Furthermore, the reconstructive potential of different peri-implant bone defect morphologies should be investigated.