Full-Digital Customized Meshes in Guided Bone Regeneration Procedures: A Scoping Review

: Meshes, especially titanium ones, are being widely applied in oral surgery. In guided bone regeneration (GBR) procedures, their use is often paired with membranes, being resorbable or non-resorbable. However, they present some limitations, such as difﬁculty in the treatment of severe bone defects, alongside frequent mesh exposure. Customized meshes, produced by a full-digital process, have been recently introduced in GBR procedures. Therefore, the focus of the present review is to describe the main ﬁndings in recent years of clinical trials regarding patient-speciﬁc mesh produced by CAD/CAM and 3D printing workﬂow, made in titanium or even PEEK, applied to GBR surgeries. The purpose is to analyze their clinical management, advantages, and complications. This scoping review considered randomized clinical trials, observational studies, cohort studies, and case series/case reports studies. Studies that did not meet inclusion criteria were excluded. The preferred reporting items for scoping reviews (PRISMA-ScR) consensus was followed. A total of 15 studies were selected for this review. Based on the studies included, the literature suggests that meshes produced by a digital process are used to restore complex and severe bone defects. Moreover, they give satisfactory aesthetic results and ﬁt the defects, counteracting grid exposure. However, more clinical trials should be conducted to evaluate long-term results, the rate of complications, and new materials for mesh manufacturing.


Introduction
The alveolar bone undergoes two successive processes after extraction or loss of a dental element: resorption and atrophy. This leads to a reduction in the alveolar ridge in the first six months in the horizontal dimension and then in the vertical dimension. Therefore, the bone is often inadequate for implant placement [1,2].
The guided bone regeneration (GBR) procedure, due to its numerous advantages, such as osteogenic stability and multidirectional osteogenesis capability, appears to be one of the most used and reliable techniques to restore bone deficits in height and/or width in association with implant treatment [3,4].
Currently, the GBR technique involves the employment of membranes, resorbable or non-resorbable, combined with bone substitute materials, depending on bone defect features [5]. the surgical field. Stiffness and strength help the osteogenesis process, stability perm bone-filling materials to maintain their volume during healing, and elasticity m decrease oral mucosa's compression [11,12].
When using surgical meshes, the main complication is wound dehiscence a subsequent mesh exposure during the healing process. Mesh exposure can be classifi as early exposure occurring within 4 weeks post-surgery and delayed mesh exposu occurring after 4 weeks post-surgery. Early dehiscence manifestation is related to reduction in new bone formation and synchronic increment in fibrous tissue; when t event occurs, the grid should be quickly eliminated, and disinfection procedures carri out [17,18]. On the other hand, late mesh exposure could potentially create substitu materials' resorption, leading to a decrease in bone dimension and inadequate quanti However, the mesh can be left in place, as disinfection with chlorhexidine, plaq management, and smoothing of the sharp edges could solve the problem witho alterations in the process of bone regeneration [19][20][21].
Standardized meshes are products with pre-determined characteristics such thickness and width; hence they must be manually modeled to adapt to the alveolar rid of the specific patient. This procedure presents many drawbacks, such as longer surge imprecise fitting, infection, pain, flap laceration, and possible future mesh exposure [2 24].
Therefore, recent clinical research has focused more on customized titanium me thanks to the latest digitalization trends and technologies available on the market (Figu 1). Pre-operative cross-sectional imaging (cone beam computed tomography-CBCT) a 3D digital models have to be collected; thus, the patient's alveolar ridge can be virtua reconstructed with CAD technology [25].
Custom-made titanium mesh can be produced with different protocols: CAD/CA 3D printing or mesh-preforming on patients' 3D jaws models [26,27].
Personalized meshes showed numerous advantages, such as quicker surge tailored fitting, less retention used to pin the mesh, smoother edges, and subseque mucosal stress reduction [11,28].  Custom-made titanium mesh can be produced with different protocols: CAD/CAM-3D printing or mesh-preforming on patients' 3D jaws models [26,27].
Personalized meshes showed numerous advantages, such as quicker surgery, tailored fitting, less retention used to pin the mesh, smoother edges, and subsequent mucosal stress reduction [11,28].
In the last decade, research has concentrated on customized mesh applications in the surgical field. Therefore, this review aims to analyze the recent literature concerning fulldigital customized mesh applied to guided bone regeneration in oral surgery, their clinical aspects and management (complex bone defects, aesthetic outcomes, bone regeneration rates), and future perspectives.

Results
The primary search identified 143 articles based on MeSH terms. Following this, 117 articles were removed (13 abstracts of articles published in non-English languages, 198 duplicates, 68 in vitro or animal clinical studies, 114 because they were not pertinent, and 9 because of the absence of Ethics Committee approval), and 26 articles were screened based on title and abstracts. The remaining 15 full-text articles were assessed for eligibility. Additionally, 11 full-text articles were further excluded because they were irrelevant articles. The 15 relevant articles were finally included and analyzed in this review. The flowchart of the review process is described in Figure 2.    [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table S4 (Supplementary Materials). A moderate risk of bias was observed in this review. Table 1. Risk of bias of the studies included in this review: the green symbol represents a low risk of bias, while the yellow symbol represents a high risk of bias.

Random Sequence Generation Allocation Concealment
Blinding Incomplete Outcome Data

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review. Table 1. Risk of bias of the studies included in this review: the green symbol represents a low risk of bias, while the yellow symbol represents a high risk of bias. De Santis et al., 2022 [55] Geletu et al., 2022 [56] hesis 2023, 5, FOR PEER REVIEW 5 [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review. Table 1. Risk of bias of the studies included in this review: the green symbol represents a low risk of bias, while the yellow symbol represents a high risk of bias.

Random Sequence Generation Allocation Concealment Blinding
Incomplete Outcome Data

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review.   [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review.   [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied included in this review (    The studies were from before-after (Pre-Post) studies [46][47][48][49][50][51], and case series/case re

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review.   [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review.   [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review.   [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied included in this review (    The studies were from before-after (Pre-Post) studies [46][47][48][49][50][51], and case series/case re

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review.  [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review.  [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review.  [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied included in this review (   The studies were from before-after (Pre-Post) studies [46][47][48][49][50][51], and case series/case re

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review. Table 1. Risk of bias of the studies included in this review: the green symbol represents a low risk of bias, while the yellow symbol represents a high risk of bias.  [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review. Table 1. Risk of bias of the studies included in this review: the green symbol represents a low risk of bias, while the yellow symbol represents a high risk of bias.  [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review. Table 1. Risk of bias of the studies included in this review: the green symbol represents a low risk of bias, while the yellow symbol represents a high risk of bias.  [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied included in this review (   The studies were from before-after (Pre-Post) studies [46][47][48][49][50][51], and case series/case re

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review. Table 1. Risk of bias of the studies included in this review: the green symbol represents a low risk of bias, while the yellow symbol represents a high risk of bias.   [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review. Table 1. Risk of bias of the studies included in this review: the green symbol represents a low risk of bias, while the yellow symbol represents a high risk of bias.   [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review. Table 1. Risk of bias of the studies included in this review: the green symbol represents a low risk of bias, while the yellow symbol represents a high risk of bias.   [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied included in this review (    The studies were from before-after (Pre-Post) studies [46][47][48][49][50][51], and case series/case re

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review. Table 1. Risk of bias of the studies included in this review: the green symbol represents a low risk of bias, while the yellow symbol represents a high risk of bias.   [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review. Table 1. Risk of bias of the studies included in this review: the green symbol represents a low risk of bias, while the yellow symbol represents a high risk of bias.   [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review. Table 1. Risk of bias of the studies included in this review: the green symbol represents a low risk of bias, while the yellow symbol represents a high risk of bias.   [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied included in this review (    The studies were from before-after (Pre-Post) studies [46][47][48][49][50][51], and case series/case re

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review.   [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review.   [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review.   [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied included in this review (    The studies were from before-after (Pre-Post) studies [46][47][48][49][50][51], and case series/case re

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review.   [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review.   [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review.   [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied included in this review (    The studies were from before-after (Pre-Post) studies [46][47][48][49][50][51], and case series/case re

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review. Table 1. Risk of bias of the studies included in this review: the green symbol represents a low risk of bias, while the yellow symbol represents a high risk of bias.   [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review. Table 1. Risk of bias of the studies included in this review: the green symbol represents a low risk of bias, while the yellow symbol represents a high risk of bias.   [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review. Table 1. Risk of bias of the studies included in this review: the green symbol represents a low risk of bias, while the yellow symbol represents a high risk of bias.   [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied included in this review (    The studies were from before-after (Pre-Post) studies [46][47][48][49][50][51], and case series/case re

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review.   [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review.   [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review.   [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied included in this review (    The studies were from before-after (Pre-Post) studies [46][47][48][49][50][51], and case series/case re

Risk of Bias
The Cochrane Collaborati included in this review (

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review.

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review.

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review.

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review. The studies were from four categories: controlled intervention studies [43,44], before-after (Pre-Post) studies with no control group [45], observational cohort studies [46][47][48][49][50][51], and case series/case report studies [52][53][54][55][56][57].

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review. The studies were from four categories: controlled intervention studies [43,44], before-after (Pre-Post) studies with no control group [45], observational cohort studies [46][47][48][49][50][51], and case series/case report studies [52][53][54][55][56][57].

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review. The studies were from four categories: c before-after (Pre-Post) studies with no control g [46][47][48][49][50][51], and case series/case report studies [52-57

Risk of Bias
The Cochrane Collaboration tool was applied included in this review ( The studies were from before-after (Pre-Post) studies [46][47][48][49][50][51], and case series/case re

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review. Table 1. Risk of bias of the studies included in this review: the green symbol represents a low risk of bias, while the yellow symbol represents a high risk of bias.   [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review. Table 1. Risk of bias of the studies included in this review: the green symbol represents a low risk of bias, while the yellow symbol represents a high risk of bias.   [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review. Table 1. Risk of bias of the studies included in this review: the green symbol represents a low risk of bias, while the yellow symbol represents a high risk of bias.   [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review. Table 1. Risk of bias of the studies included in this review: the green symbol represents a low risk of bias, while the yellow symbol represents a high risk of bias.   [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review. Table 1. Risk of bias of the studies included in this review: the green symbol represents a low risk of bias, while the yellow symbol represents a high risk of bias.   [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table  S4 (Supplementary Materials). A moderate risk of bias was observed in this review. Table 1. Risk of bias of the studies included in this review: the green symbol represents a low risk of bias, while the yellow symbol represents a high risk of bias.   [32][33][34][35][36][37][38][39][40][41][42].

Risk of Bias
The Cochrane Collaborati included in this review (   Inclusion criteria: patients who had a partial or completely edentulous maxillary alveolar ridge with apparent 3D defect following teeth loss. The ridge had to exhibit severe vertical and horizontal (3D) alveolar ridge deficiency with alveolar ridge height less than 6 mm from the alveolar crest to the basal bone and a ridge width of less than 2 mm or a clinically apparent increase in inter-arch space relative to the adjacent natural teeth.  55.9 ± 13.7 Inclusion criteria: the absence of any systemic or local contraindication to surgical treatment: acute or chronic infections in the head and neck; smoking > 10 cigarettes per day; uncontrolled diabetes; a history of radiation therapy in the head or neck region; current anti-tumor chemotherapy; liver, blood, or kidney disease; immunosuppression; everyday corticosteroid use; pregnancy; inflammatory and autoimmune disease of the oral cavity; and poor oral hygiene and motivation. The specific conditions for intervention were the presence of maxillary or mandibular complex defects (with horizontal and vertical deficits in the same site), which was considered inadequate for the placement of at least two standard fixtures (≥6 mm long and ≥3.3 wide).   Inclusion criteria: systemically healthy patients; a minimum age of 18 years; relevant or severe bone atrophy at the edentulous sites incompatible with placement of even short (≤6 mm) or narrow (<3 mm) implants in an appropriate and prosthetically guided position; adequate compliance of patients, both in terms of oral hygiene and respect the follow-up recalls; and ability to understand the proposed surgical treatment and to understand and sign the informed consent. Exclusion criteria: severe kidney and/or liver disease; congenital or acquired immunodeficiency; ongoing antiblastic chemotherapy at the time of first examination; sequelae of radiotherapy in the head and neck area; oral mucosa disease, such as lichen planus; FMPS and FMBS > 20%; non-compliant patients; tobacco (>10 cigarettes per day) or alcohol abuse; non compensated diabetes; active periodontal disease at the time of first examination (in these cases, patients underwent etiologic therapy and motivation in personal oral hygiene and were re-evaluated for surgical treatment); bisphosphonate chemotherapy in progress; and pregnant women.

Discussion
A total of 15 studies belonging to 4 different categories (controlled intervention studies, observational cohort studies, before-after (Pre-Post) studies with no control group, and case series/case report studies) were considered in this review.
In the last few years, thanks to recent digital technologies development and new materials testing, the GBR procedure has improved its clinical outcomes. Materials such as titanium (Ti) and polyether-ether-ketone (PEEK) have been used to perform alveolar bone enhancement and reconstruction thanks to their antimicrobial and osteogenic aspects [58]. Concerning oncologic, traumatological, and implantology fields, alveolar bone dimensions are fundamental to satisfy both aesthetic and functional aspects [59]. In the recent literature, several authors suggested customized mesh as an efficient device to reconstruct complex or severe bone deficits, intended as wide horizontal or vertical deficiencies or even the combination of both [45,60]. Therefore, this scoping review focuses on clinical management and clinical outcomes of the GBR procedure using custom-made full-digital meshes.

Bone Defect Dimension
The 3D technology and additive manufacturing procedure development permitted the creation of a patient-specific grid for GBR, established on the bone defect dimension, with notable properties, being physical or biological [27,61]. Contrary to standard Timesh, the 3D-printed ones have smooth margins, with the chance of reducing mucosal detriment and consequential mesh exposure, the main complication occurring after GBR surgery. Moreover, bone deficits could be reconstructed more accurately and patientspecifically [28,62].
Some studies showed that 3D precision of bone increment is not significantly related to bone deficit dimensions, being minor or major bone defects [51]. Large combined alveolar bone defects in a horizontal and vertical dimension and simultaneous implant placement could be safely and predictably treated with virtual planning and CAD/CAM patientspecific mesh manufacturing [53]. The 3D patient models used for shaping the customized mesh permit a correct fitting to the alveolar bone.
Vertical bone deficiency can be efficiently treated with up to a 90% bone regeneration rate [45,46]. In complex bone defects, patient-specific Ti-mesh has been demonstrated to potentially concur to significant bone augmentation up to 11.48 mm in horizontal and 8.90 mm in vertical dimensions, suggesting laser-sintered CAD/CAM mesh as a reliable alternative in GBR procedure related to extended atrophic alveolar ridges [49].

Aesthetic Aspects
Maxillary and mandibular defects, being related to traumatic, tumoral, or congenital conditions, can significantly impact functional and aesthetic aspects of patients' lives; thus, their reconstruction is essential [63]. A key factor to consider when restoring aesthetic and functional features is the application of a grid, which permits obtaining and reinforcing 3D bone reconstruction.
Digital planning of the surgical procedure and tailored mesh permit the maintenance of bone shape. Additionally, they cooperate in the correct positioning of graft material to place implant fixtures and enhance the precision of bone augmentation and maxillary interconnection [50,64]. Regarding the anterior maxillary region, aesthetic considerations need to be conducted. Implant placement is strictly related to an adequate volume of alveolar bone. Thus, individualized mesh seems to give promising results as far as it concerns bone augmentation and aesthetics [56].
In patients who present critical concavities of the vestibular bone, virtual bone volume augmentation and customized titanium mesh fabrication through 3D-printing technology showed a notable bone augmentation (after 6 months 3.7 mm SD ± 0.59 and after 12 months 4.3 mm (SD ± 0.83) [54].
When positioning a personalized 3D Ti-mesh, it is important to consider the chance of obtaining good soft tissue management as well as good aesthetic results with voluminous and healthy tissue characteristics without any signs of scar or fibrosis [52].
A possible solution to ensure a complex bone regeneration in the aesthetic area could be a fully digital protocol that some clinicians already apply. This combines patient-specific titanium mesh with a prosthetically guided regeneration (PGR) to achieve predictable and satisfactory outcomes (Figures 3 and 4) [57].
Specifically, overlaying a digital diagnostic wax-up can make the bone reconstruction procedure prophetically guided, allowing the maintenance of an adequate buccal cortical to ensure a satisfactory esthetic outcome [65,66]. nous and healthy tissue characteristics without any signs of scar or fibrosis A possible solution to ensure a complex bone regeneration in the aesthe be a fully digital protocol that some clinicians already apply. This combine cific titanium mesh with a prosthetically guided regeneration (PGR) to achiev and satisfactory outcomes (Figures 3 and 4) [57].   Specifically, overlaying a digital diagnostic wax-up can make the bone recons procedure prophetically guided, allowing the maintenance of an adequate buccal to ensure a satisfactory esthetic outcome [65,66].

Biological Considerations
Considering the histological characteristics of augmented alveolar bone, th digital and individualized meshes, the freshly regenerated bone appeared miner different stages. Close to the bone substitute materials residues in the connective medullary cavities, no signs of inflammation were noticed, leading to a newly rege tissue with structure, organization, vitality, and functioning processes of remode assimilation of grafting materials [47].
Associated with bone regeneration, in the case of custom-made grid pos

Biological Considerations
Considering the histological characteristics of augmented alveolar bone, thanks to digital and individualized meshes, the freshly regenerated bone appeared mineralized at different stages. Close to the bone substitute materials residues in the connective tissue or medullary cavities, no signs of inflammation were noticed, leading to a newly regenerated tissue with structure, organization, vitality, and functioning processes of remodeling and assimilation of grafting materials [47].
Associated with bone regeneration, in the case of custom-made grid positioning, rapid and natural re-epithelialization under the intern portion of the mesh was noticed. This sign may be related to the initial bone augmentation with limited depletion [49].

Clinical Success and Complications
Virtual planning and personalized grid manufacturing associated with flap layout and its control are crucial aspects to consider in order to achieve clinical success in the GBR procedure [55]. Individualized Ti-meshes are more rigid than standard ones; thus, mesh exposure could happen eventually, even with this digital procedure [67]. This may be due to mechanical stress to the mucosal tissue's flap, post-surgical removable prosthesis positioning, or eventually, the digital software learning curve and grid-projecting procedures [48].
Thus, a prudent approach must be adopted to ensure the clinical success of the procedure and avoid complications. Some authors showed that the application of a resorbable membrane above the customized mesh could reduce healing complication rates (13.3% vs. 33.3%) [43].

Early and Late Complication Management
In the case of mesh exposure, correct management can still lead to GBR success. The treatment consists of pharmacological or mechanical procedures.
Mesh exposure that occurs within 4 weeks after the surgical procedure is usually treated with chlorhexidine 0.2% (CHX) gels applied two to four times daily, followed by curettage of the interested site until tissue healing. Bone augmentation for implant positioning purposes is not limited in any way [21,68].
Alternatively, for CHX gel applications, the literature also suggests CHX mouthwashes or CHX spray with heterogeneous concentrations. However, gel preparations seem to be more effective than mouthwashes [69].
In the case of suspects of graft infection, topical antibiotic administration becomes relevant, while in the occurrence of mesh exposure, antibiotic administration is scarcely reported in the literature. This condition requires immediate mesh removal because of infection and pus. Plaque control and correct oral hygiene are also fundamental in these stages. Hence, saline washes and toothbrushes allow plaque removal [21].
For late exposure management, CHX 0.2% or, in some cases, 1% gel application two times a day until tissue healing appears to be useful and permits the maintenance of the mesh [20,70].
Mechanical smoothing of mesh edges with carbide or diamond burs for late exposure helps to create secondary healing of the wound [71,72].

New Materials
Despite titanium mesh being the most utilized material in guided-bone-regeneration processes, recently, the research has focused on different materials. Since PEEK material is starting to be broadly applied in the surgical field-orthopedic, traumatological, or even craniomaxillofacial-due to its inertness and biocompatibility, it could also be used in regenerative approaches [73,74].
In GBR procedures, customized PEEK grids have been applied to three-dimensional alveolar bone defects to place implant fixtures, and it has been demonstrated that there are no statistical differences (p-value = 0.2) between PEEK and pre-bent Ti-mesh, as far as it concerns bone regenerative processes [44].
Full-digital meshes represent one component of a digitization process that includes other stages that complete a surgical case, such as case design, CAD/CAM abutments and crowns, and other 3D-printed components [75][76][77][78].
This report presents some limitations. The search procedure could have been too specific for a scoping question. Moreover, the comparison between results could be complicated and might vary depending on the sample considered; indeed, digital software may give different results considering individual learning curves or technicians' capabilities. The same consideration should be applied to surgical procedures, mesh positioning, and management, which can vary based on clinician experience or patient compliance. Lastly, the heterogeneity of digital software and 3D-printing devices available on the market can influence clinical results and thus clinical trial outcomes.
Future studies, especially randomized clinical trials, are needed to deeply analyze customized mesh produced through digital approaches for complex defects and new material testing other than titanium, as well as their complication rates.

Conclusions
The recent development of digital technologies such as CAD/CAM and 3D printing permits the creation of full-digital customized meshes, which can be applied in GBR procedures.
Personalized meshes are used to restore complex and severe bone defects, giving satisfactory aesthetic results. They adapt to the defects, counteracting grid exposure.
However, more studies should be conducted to evaluate long-term results, the rate of complications, and eventually to test new materials or technologies for mesh manufacturing.
Supplementary Materials: The following supporting information can be downloaded at: https: //www.mdpi.com/article/10.3390/prosthesis5020033/s1, Table S1: PRISMA-ScR checklist.; Table S2: Search strategies for electronic databases; Table S3: Summary table of studies excluded in this scoping review; Table S4: Criteria for judging risk of bias in the "Risk of bias" assessment tool; Table S5: Evidence of studies included in this scoping review;