This special issue on autologous platelet concentrates (APCs) provides clinicians with an overview on the current understanding of the use of these biomaterials for soft and hard-tissue regeneration. The included papers summarize scientific evidence and the clinical findings, presented in simple tables that outline potential benefits including Patient Reported Outcome Measures (PROMs). This approach enables clinicians to assess clinical relevance and researchers to identify significant gaps in the literature. The first part provides a comprehensive summary of the basic science surrounding APC, with particular focus on their preparation methods. Clear recommendations are outlined, which are crucial for obtaining high-quality APCs, alongside an exploration of how APCs may influence both soft and hard tissue healing processes. Part 2 delves into the clinical evidence for the potential benefits of APCs across a range of applications: alveolar ridge preservation, sinus floor elevation, periodontal plastic surgery, guided tissue regeneration, guided bone regeneration, the healing of Medication-Related Osteonecrosis of the Jaw (MRONJ), and endodontic surgery. In the part 3, the discussion turns to the effects of APCs on the healing of extra-oral wounds, including diabetic foot ulcers, venous leg ulcers, pressure injuries, burns, and more. For those clinicians persuaded by the evidence, the fourth section offers a detailed, step-by-step flowchart for each treatment modality, providing a clear guide for clinical application.

BACKGROUND: Current flap-releasing designs for guided bone regeneration (GBR) emphasize preserving subperiosteal microvasculature by adapting a deep slit approach, separating theperiosteum from the flap. While biologically sound, a biomechanical disadvantage may be encountered. This study aimed to describe a modified design, the Secured Anatomy-driven Flap Extension (SAFE) technique, for effective facial flap release and to preliminarily evaluate the clinical outcomes of this technique retrospectively.
METHODS: Chart reviews were conducted to identify patients treated by facial flap release in staged GBR procedures between May 2020 and March 2022. The anatomical, biological, and biomechanical rationale of this technique were described. The following clinical data were collected: intraoperative and postoperative complications, initial and final horizontal ridge width before and 5-6 months after the GBR, and implant performance.
RESULTS: A total of 10 patients were identified. At baseline, these patients presented with a mean ridge width of 2.05 ± 0.52 mm. No intraoperative and postoperative complications were observed in these patients (bleeding, wound opening, neurosensory disturbance, etc.) at the 2-3-week follow-up visit. At the re-entry, a mean ridge width of 6.50 ± 0.55 mm was measured (p < 0.01), resulting in a mean of 4.45 ± 0.65 mm ridge width gain. Twenty-one implants were successfully placed, integrated, and in function without signs/symptoms of peri-implantitis after a mean 21.5 ± 9.2 months follow-up period.
CONCLUSIONS: Preliminary results suggest that the SAFE technique is a safe and predictable approach for releasing facial flaps during GBR procedures.

OBJECTIVE: To evaluate the efficacy of guided bone regeneration (GBR) for the treatment of peri-implant dehiscence defects using a synthetic bone substitute (SBS) or a deproteinized bovine bone mineral (DBBM) as a bone substitute.
METHODS: Patients with expected dehiscence defects following implant placement were randomized to use either SBS or DBBM together with a bioabsorbable collagen membrane over dehiscenced implant surfaces aimed for GBR. The changes in the bone defect size were measured before the GBR procedure and 6 months after implant placement at the re-entry surgery. Secondary outcomes included peri-implant health outcomes, implant cumulative survival rates, bone level changes, and patient-reported outcomes (PROMs) at prosthesis delivery and 1-year follow-up.
RESULTS: Of the 49 included patients, 24 were treated with SBS and 25 with DBBM. In the SBS group, the defect height (DH) at implant insertion was 5.1 ± 2.6 mm and was reduced at re-entry to 1.3 ± 2.0 mm (74.5%). In the DBBM group, the respective changes in DH were 4.1 ± 1.7 mm and 1.5 ± 1.9 mm (63.4%). These differences were not statistically significant (p = 0.216). The complete defect resolution rate was also comparable in both groups without statistical difference (62.5% of patients (15/24) vs. 44% of patients (11/25)). Overall, the marginal bone levels remained stable during the 1-year follow-up in both groups.
CONCLUSIONS: The SBS is noninferior to DBBM for simultaneous GBR to implant placement at implant sites with buccal dehiscences in terms of defect resolution and evaluated secondary outcomes (KCT0008393 - this clinical trial was not registered before participant recruitment and randomization).

Guided bone regeneration (GBR) technology has been demonstrated to be an effective method for reconstructing bone defects. A membrane is used to cover the bone defect to stop soft tissue from growing into it. The biosurface design of the barrier membrane is key to the technology. In this work, an asymmetric functional gradient Janus membrane was designed to address the bidirectional environment of the bone and soft tissue during bone reconstruction. The Janus membrane was simply and efficiently prepared by the multilayer self-assembly technique, and it was divided into the polycaprolactone isolation layer (PCL layer, GBR-A) and the nanohydroxyapatite/polycaprolactone/polyethylene glycol osteogenic layer (HAn/PCL/PEG layer, GBR-B). The morphology, composition, roughness, hydrophilicity, biocompatibility, cell attachment, and osteogenic mineralization ability of the double surfaces of the Janus membrane were systematically evaluated. The GBR-A layer was smooth, dense, and hydrophobic, which could inhibit cell adhesion and resist soft tissue invasion. The GBR-B layer was rough, porous, hydrophilic, and bioactive, promoting cell adhesion, proliferation, matrix mineralization, and expression of alkaline phosphatase and RUNX2. In vitro and in vivo results showed that the membrane could bind tightly to bone, maintain long-term space stability, and significantly promote new bone formation. Moreover, the membrane could fix the bone filling material in the defect for a better healing effect. This work presents a straightforward and viable methodology for the fabrication of GBR membranes with Janus-based bioactive surfaces. This work may provide insights for the design of biomaterial surfaces and treatment of bone defects.

Complications that occur after maxillary sinus floor augmentation (MSA) can be divided into early and late complications. Early complication is a side effect that occurs during the MSA procedure or during the initial healing period. Usually, late complication refers to a side effect that occurs after 3 weeks of MSA. However, in the longer term, there are cases that occur during the follow-up period after the prosthesis is delivered, and most of them present with peri-implantitis. In the present two cases, sinus graft complications occurred 1-2 years after prosthesis delivery but were independent of peri-implantitis and had atypical features showing asymptomatic results. Although the route of the infection source is unclear, the lesions were presumed to be caused by slow and delayed inflammation of oral bacteria infiltrating the bone graft area of the maxillary sinus. Within the limitations of present case reports, bone defects were successfully managed with a guided bone regeneration (GBR) procedure that included thorough defect degranulation, surface decontamination of exposed implant, and regrafting. Periodic monitoring of radiographic images is required for the detection of unusual sinus graft complications in sinus-augmented sites.

The aim of the present systematic review was to compare three ridge augmentation procedures in order to assist clinicians in finding the ideal surgical method relative to the horizontal bone gain needed and the width of the alveolar ridge available. An electronic and hand literature search was performed in the online databases PubMed-Medline, Cochrane Central Register of Controlled Trials, EMBASE, Cochrane Oral Health Group Trials Register and Web of Science, and various specialized journals, between January 2017 and December 2022. The included studies were evaluated using the Methodological Index for Non-randomized Studies score and Cochrane\'s RoB tool. The primary variable studied in the meta-analysis was the final bone gain. The implant survival rate and initial ridge width were the secondary variables. Then four studies on ridge expansion via osseodensification (OD), seven on guided bone regeneration (GBR) and seven on the ridge-split technique (RS) were included in the review; 17 out of 18 were selected for meta-analysis. The mean horizontal bone gain for OD was 2.151 mm [1.327-2.975 mm; 95% confidence interval (CI)], for GBR was 4.036 mm (3.351-4.772 mm 95%CI) and for RS was 3.661 mm (2.991-4.399 mm 95%CI). The results were statistically significant (P=0.002). GBR reported the most bone gain horizontally, followed closely by RS and then OD. OD is a recent technique that should be taken into account when discussing the protocols of horizontally atrophied ridge rehabilitation.

UNASSIGNED: Surgical intervention is necessary to address significant three-dimensional bone loss in the posterior mandibular alveolar ridge when implants are planned, and primary stability cannot be achieved due to anatomical limitations. The objective of this study is to elucidate the surgical procedures for reconstructing significant bone loss in the posterior mandibular region and to present the outcomes and insights gained from this clinical case.
METHODS: A 42-year-old woman exhibited first lower molar loss, significant movement of the second molar, and severe bone loss at the same site. Vertical and horizontal bone augmentation was performed to enable the restoration of teeth loss by inserting dental implants.
UNASSIGNED: Significant bone loss poses a great limitation in replacing missing teeth, particularly in the posterior mandible, given anatomical constraints. Therefore, it is essential to establish an adequate amount of bone to ensure primary stability for the implants.
CONCLUSIONS: This clinical case demonstrates a restoration technique of severe bone loss in the posterior mandible to enable stable dental implant placement, highlighting the importance of combining vertical and horizontal augmentation to overcome anatomical limitations and ensure primary stability.

OBJECTIVE: To assess the clinical and radiographic outcomes of alveolar ridge augmentation using a novel three-dimensional printed individualized titanium mesh (3D-PITM) for guided bone regeneration (GBR).
METHODS: Preoperative cone-beam computed tomography (CBCT) was used to evaluate alveolar ridge defects, followed by augmentation with high-porosity 3D-PITM featuring circular and spindle-shaped pores. Postoperative CBCT scans were taken immediately and after 6 months of healing. These scans were compared with preoperative scans to calculate changes in bone volume, height, and width, along with the corresponding resorption rates. A statistical analysis of the results was then conducted.
RESULTS: A total of 21 patients participated in the study, involving alveolar ridge augmentation at 38 implant sites. After 6 months of healing, the average bone augmentation volume of 21 patients remained at 489.71 ± 252.53 mm3, with a resorption rate of 16.05% ± 8.07%. For 38 implant sites, the average vertical bone increment was 3.63 ± 2.29 mm, with a resorption rate of 17.55% ± 15.10%. The horizontal bone increment at the designed implant platform was 4.43 ± 1.85 mm, with a resorption rate of 25.26% ± 15.73%. The horizontal bone increment 2 mm below the platform was 5.50 ± 2.48 mm, with a resorption rate of 16.03% ± 9.57%. The main complication was exposure to 3D-PITM, which occurred at a rate of 15.79%.
CONCLUSIONS: The novel 3D-PITM used in GBR resulted in predictable bone augmentation. Moderate over-augmentation in the design, proper soft tissue management, and rigorous follow-ups are beneficial for reducing the graft resorption and the incidence of exposure.

The gold standard for bone regeneration in atrophic ridge patients is guided bone regeneration (GBR). This makes it possible to get enough bone volume for an appropriate implant-prosthetic rehabilitation. The barrier membranes must meet the primary GBR design requirements, which include adequate integration with the surrounding tissue, spaciousness and clinical manageability. Titanium mesh\'s superior mechanical qualities and biocompatibility have broadened the indications of GBR technology, enabling it to be used to restore alveolar ridges with more significant bone defects. GBR with titanium mesh is being used in many clinical settings and for a range of clinical procedures. Furthermore, several advancements in digitalization and material modification have resulted from the study of GBR using titanium mesh. Hence, we report a review on the various characteristics of titanium mesh and its current use in clinical settings for bone augmentation.

Background: Guided bone regeneration (GBR) is a reliable technique used in vertical and horizontal bone defects. The posterior mandibular region is an area limited by anatomic constraints. The use of resorbable membranes with a cortical component could compensate for the lack of rigidity of resorbable membranes without the complications of non-resorbable membranes. The aim of this study was to evaluate the mean bone gains of a xenogeneic cortical membrane in horizontal and vertical bone defects in comparison with other membranes in the literature. Methods: A porcine cortical membrane was used to perform 7 GBR in the posterior mandibular region of five patients. Preoperative (T0) and six months postoperative (T1) cone beam computed tomography were superimposed to measure the horizontal and vertical bone gain. Implants were positioned at all sites, six months after GBR. Complications and bone resorption around the implants were also documented. Results: The mean horizontal and vertical bone gains were 3.83 ± 1.41 mm and 4.17 ± 1.86 mm, respectively. The analysis of repeatability was 0.997. As many as 40% of patients experienced pain refractory to analgesics. No exposure or infectious phenomenon was observed. Conclusions: This xenogeneic cortical membrane seemed to provide interesting results in the regeneration of horizontal and vertical bone defects. Comparative and prospective studies are necessary to validate the effectiveness of this membrane.